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NLM database Documents
Record 1 from database: MEDLINE
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- Title
- Role of cholesterol 10-methyl group and effect of
"extra" 14-methyl group on silkworm growth and
development.
- Author
- Mamiya M; Takahashi K; Eguchi S; Morisaki M
- Address
-
- Source
- Chem Pharm Bull (Tokyo), 1989 Jul, 37:7, 1930-1
- Abstract
- In order to establish the functional importance of the
10-methyl group of cholesterol and the planarity of the
steroid ring, silkworms (Bombyx mori) were reared on an
artificial diet containing 19-norcholesterol (1), 14 alpha-methylcholesterol
(3) or 19,19-difluorocholesterol (2). The former two sterols
(1 and 3) only partially satisfied the silkworm sterol
requirement; growth and development were seriously retarded.
The fluorinated sterol (2) was much more deleterious and was
totally inadequate in meeting the sterol requirement.
- Language of Publication
- English
- Unique Identifier
- 90030589
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- MeSH Heading (Major)
- Cholesterol|AA/*PD; Silkworms|*GD
- MeSH Heading
- Animal; Structure-Activity Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0009-2363
- Country of Publication
- JAPAN
Record 2 from database: MEDLINE
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- Title
- The allyl group for protection in carbohydrate chemistry.
17. Synthesis of propyl
O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-
di-O-methyl-alpha-L-rhamnopyranosyl)-(1----2)-3-O-methyl-alpha-
L-rhamnopyranoside: the oligosaccharide portion of the major
serologically active glycolipid from Mycobacterium leprae.
- Author
- Gigg J; Gigg R; Payne S; Conant R
- Address
-
- Source
- Chem Phys Lipids, 1985 Sep, 38:3, 299-307
- Abstract
- Allyl 4-O-benzyl-alpha-L-rhamnopyranoside was converted
into allyl 4-O-benzyl-3-O-methyl-alpha-L-rhamnopyranoside
and this was condensed with
2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl chloride to give
a disaccharide derivative which was converted into allyl
4-O-benzyl-2-O-(2,3-O-isopropylidene-alpha-L-rhamnopyranosyl)-3-O-methyl
-alpha- L-rhamnopyranoside. This disaccharide derivative was
condensed with
2,4-di-O-acetyl-3,6-di-O-methyl-alpha-D-glucopyranosyl
chloride to give a trisaccharide derivative which was
converted into the title compound. This compound represents
the oligosaccharide portion of the major serologically
active glycolipid from Mycobacterium leprae which is
required to prepare a synthetic diagnostic agent for leprosy
infection at an early stage and to investigate the
specificities of monoclonal antibodies directed towards the
glycolipid.
- Language of Publication
- English
- Unique Identifier
- 86106478
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- MeSH Heading (Major)
- Glycolipids|*CS; Mycobacterium leprae|*IM;
Oligosaccharides|*CS; Trisaccharides|*CS
- MeSH Heading
- Indicators and Reagents; Optical Rotation; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0009-3084
- Country of Publication
- NETHERLANDS
Record 3 from database: MEDLINE
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- Title
- Methyl-glyoxal bis guanyl hydrazone (methyl-GAG, MGBG) in
lymphoma and Hodgkin's disease. A Phase II trial of the
Southwest Oncology Group.
- Author
- Knight WA 3d; Fabian C; Costanzi JJ; Jones SE; Coltman CA
Jr
- Address
-
- Source
- Invest New Drugs, 1983, 1:3, 235-7
- Abstract
- The Southwest Oncology Group has evaluated methyl-GAG on a
weekly schedule among patients with lymphoma and Hodgkin's
disease. Among 56 fully and partially evaluable patients
responses were seen in 3 of 10 patients with Hodgkin's
disease and 11 of 46 patients with lymphoma. Toxicity was
acceptable. Methyl-GAG has significant antitumor activity
among this group of heavily pretreated patients. Additional
trials of methyl-GAG in combination with other agents are
underway.
- Language of Publication
- English
- Unique Identifier
- 84288336
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- MeSH Heading (Major)
- Guanidines|*TU; Hodgkin Disease|*DT; Lymphoma|*DT;
Mitoguazone|AE/*TU
- MeSH Heading
- Adolescence; Adult; Aged; Drug Evaluation; Female; Human;
Male; Middle Age; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0167-6997
- Country of Publication
- UNITED STATES
Record 4 from database: MEDLINE
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- Title
- Evidence for methyl group transfer between the
methyl-accepting chemotaxis proteins in Bacillus subtilis.
- Author
- Bedale WA; Nettleton DO; Sopata CS; Thoelke MS; Ordal GW
- Address
- Department of Biochemistry, College of Medicine,
University of Illinois, Urbana 61801.
- Source
- J Bacteriol, 1988 Jan, 170:1, 223-7
- Abstract
- We present evidence for methyl (as methyl or methoxy)
transfer from the methyl-accepting chemotaxis proteins H1
and possibly H3 of Bacillus subtilis to the methyl-accepting
chemotaxis protein H2. This methyl transfer, which has been
observed in vitro (D. J. Goldman and G. W. Ordal,
Biochemistry 23:2600-2606, 1984), was strongly stimulated by
the chemoattractant aspartate and thus may play an important
role in the sensory processing system of this organism.
Although radiolabeling of H1 and H3 began at once after the
addition of [3H]methionine, radiolabeling of H2 showed a
lag. Furthermore, the addition of excess nonradioactive
methionine caused immediate exponential delabeling of H1 and
H3 while labeling of H2 continued to increase. Methylation
of H2 required the chemotactic methyltransferase, probably
to first methylate H1 and H3. Aspartate caused increased
labeling of H2 and strongly decreased labeling of H1 and H3
after the addition of nonradioactive methionine. Without the
addition of nonradioactive methionine, aspartate caused
demethylation of H1 and to a lesser extent H3, with an
approximately equal increase of methylation of H2.
- Language of Publication
- English
- Unique Identifier
- 88086873
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- MeSH Heading (Major)
- Bacillus subtilis|*ME; Chemotactic Factors|*ME; Membrane
Proteins|*ME
- MeSH Heading
- Electrophoresis, Polyacrylamide Gel; Methylation; Support,
U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9193
- Country of Publication
- UNITED STATES
Record 5 from database: MEDLINE
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- Title
- The methyl folate trap. A physiological response in man to
prevent methyl group deficiency in kwashiorkor (methionine
deficiency) and an explanation for folic-acid induced
exacerbation of subacute combined degeneration in pernicious
anaemia.
- Author
- Scott JM; Weir DG
- Address
-
- Source
- Lancet, 1981 Aug, 2:8242, 337-40
- Abstract
- It is suggested that in man the methyl folate trap is a
normal physiological response to impending methyl group
deficiency resulting from a very low supply of methionine.
This decreases cellular S-adenosyl-methionine (SAM), which
puts at risk important methylation reactions, including
those required to maintain myelin. In order to protect these
methylation reactions, the cell has evolved two mechanisms
to maintain supplies of methionine and SAM as a first
priority. (a) Decreased SAM causes the folate co-factors to
be directed through the cycle involving
5-methyl-tetrahydrofolate (5-methyl-THF) and methionine
synthetase and away from the cycles that produce purines and
pyrimidines for DNA synthesis. This enhances the
remethylation of homocysteine to methionine and SAM. In
addition, by restricting DNA biosynthesis and with it cell,
division, competition for methionine for protein synthesis
is reduced. Thus, whatever methionine is available is
conserved for the vital methylation reactions in the nerves,
brain, and elsewhere. (b) 5-methyl-THF, the form in which
almost all folate is transported in human plasma, must react
with intracellular homocysteine before it can be retained by
the cell as a polyglutamate. Since homocysteine is derived
entirely from methionine, methionine deficiency will cause
intracellular folate deficiency, and the rate of mitosis of
rapidly dividing cells will be reduced. although these two
processes have evolved as a response to methionine
deficiency, they also occur in B12 deficiency, which the
cell mistakenly interprets as lack of methionine. the
resulting response is inappropriate and gives rise to a
potentially lethal anaemia. In these circumstances the
methylation reactions are also partly protected by the
reduced rate of cell division. This explains why
administration of folic acid, which induces cell division
and use of methionine in protein synthesis, impairs
methylation of myelin and precipitates or exacerbates
subacute combined degeneration (SCD). During folate
deficiency methionine biosynthesis is also diminished. As in
methionine deficiency, the body responds to decreasing
availability of SAM by diverting folate away from DNA
biosynthesis towards the remethylation of homocysteine to
methionine and SAM. The selective use pf available folate to
conserve methionine, together with the ability of nerve
tissue to concentrate folate form the plasma, explains the
absence of SCD in folate deficiency.
- Language of Publication
- English
- Unique Identifier
- 81269413
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- MeSH Heading (Major)
- Anemia, Pernicious|*ME; Folic Acid|*PH; Kwashiorkor|*PC;
Methionine|*DF/PH; Methotrexate|*AA/ME; Models, Biological|*
- MeSH Heading
- Acute Disease; Bone Marrow|ME; Cell Division; Folic Acid
Deficiency|CO; Human; Vitamin B 12 Deficiency|CO
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0140-6736
- Country of Publication
- ENGLAND
Record 6 from database: MEDLINE
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- Title
- Influence of the presence of a methyl group on the
myocardial metabolism of 15-(paraiodophenyl)-3 methyl
pentadecanoic acid (IMPPA).
- Author
- Humbert T; Keriel C; Batlle DM; Leverve X; Luu Duc C;
Cuchet P; Comet M
- Address
- Laboratoire de Chimie Pharmacie, URA CNRS 1287, Grenoble,
France.
- Source
- Int J Rad Appl Instrum [B], 1990, 17:8, 745-9
- Abstract
- The objective of the present study was to determine the
mechanism of accumulation of myocardial activity following
i.v. injection of 15-(paraiodophenyl)-3 methyl pentadecanoic
acid (IMPPA). IMPPA and 15 phenyl-3 methyl pentadecanoic
acid (MPPA) were labeled with 14C at position 1 and used to
perfuse isolated rat hearts in a closed system. After 5 min
of perfusion, IMPPA reached 2/3 of its value at 45 min.
14CO2 production was low. Most of the myocardial activity
was in the form of free IMPPA. Analysis of IMPPA activation
by CoA SH revealed that it was very strongly inhibited. The
retention of myocardial activity is thus due to
intracellular accumulation of free IMPPA following
inhibition of activation. Comparison of results obtained
with IMPPA and MPPA showed that the presence of iodine in
the molecule accentuates the inhibition of activation.
- Language of Publication
- English
- Unique Identifier
- 91177698
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- MeSH Heading (Major)
- Iodobenzenes|*PK; Myocardium|*ME
- MeSH Heading
- Animal; Carbon Radioisotopes; Coenzyme A Ligases; Fatty
Acids|PK; Female; In Vitro; Rats; Rats, Inbred Strains
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0883-2897
- Country of Publication
- UNITED STATES
Record 7 from database: MEDLINE
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- Title
- Reductive activation of the corrinoid-containing enzyme
involved in methyl group transfer between methyl-tetrahydromethanopterin
and coenzyme M in Methanosarcina barkeri.
- Author
- van de Wijngaard WM; Lugtigheid RL; van der Drift C
- Address
- Department of Microbiology, Faculty of Science, University
of Nijmegen, The Netherlands.
- Source
- Antonie Van Leeuwenhoek, 1991 Jul, 60:1, 1-6
- Abstract
- The conversion of methyl-tetrahydromethanopterin to
methylcoenzyme M in Methanosarcina barkeri is catalyzed by
two enzymes: an enzyme with a bound corrinoid, which becomes
methylated during the reaction and an enzyme which transfers
the methyl group from this corrinoid to coenzyme M. As in
the similar methyltransfer reaction in Methanobacterium
thermoautotrophicum the corrinoid enzyme in M barkeri needs
to be activated by H2 and ATP. ATP can be replaced by
Ti(III)citrate or CO.
- Language of Publication
- English
- Unique Identifier
- 92181106
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- MeSH Heading (Major)
- Mesna|*AA/ME; Methanosarcina barkeri|*EN/ME;
Methyltransferases|*CH; Pterins|*ME
- MeSH Heading
- Adenosine Triphosphate|ME; Carbon Monoxide|ME; Citrates|ME;
Enzyme Activation; Formaldehyde|ME; Hydrogen|ME; Methylation;
Oxidation-Reduction; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-6072
- Country of Publication
- NETHERLANDS
Record 8 from database: MEDLINE
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- Title
- Methyl-glyoxal bis guanyl hydrazone (methyl-GAG, MGBG) in
advanced breast cancer. A Phase II trial of the Southwest
Oncology Group.
- Author
- Knight WA 3d; OBryan RM; Samal B; Costanzi JJ
- Address
-
- Source
- Invest New Drugs, 1984, 2:1, 71-3
- Abstract
- The Southwest Oncology Group has evaluated methyl-GAG on a
weekly schedule among patients with metastatic breast
cancer. Among 72 fully and partial evaluable patients, one
complete and four partial responses were seen. Toxicity was
similar to other trials with this compound except for
thrombocytopenia which was more frequent and severe and
probably related to tumor infiltrating marrow. In addition,
one patient experienced recall dermatitis following
methyl-GAG. This toxicity has not been previously reported
with this compound. Methyl-GAG has minimal activity at this
dose and schedule among heavily pretreated patients with
breast cancer.
- Language of Publication
- English
- Unique Identifier
- 84288364
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- MeSH Heading (Major)
- Breast Neoplasms|*DT; Guanidines|*TU; Mitoguazone|AE/*TU
- MeSH Heading
- Adult; Aged; Drug Evaluation; Female; Human; Middle Age;
Neoplasm Metastasis; Support, U.S. Gov't, P.H.S.;
Thrombocytopenia|CI
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0167-6997
- Country of Publication
- UNITED STATES
Record 9 from database: MEDLINE
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- Title
- Influence of attractants and repellents on methyl group
turnover on methyl-accepting chemotaxis proteins of Bacillus
subtilis and role of CheW.
- Author
- Hanlon DW; Carpenter PB; Ordal GW
- Address
- Department of Biochemistry, College of Medicine,
University of Illinois, Urbana 61801.
- Source
- J Bacteriol, 1992 Jul, 174:13, 4218-22
- Abstract
- The ability of attractants and repellents to affect the
turnover of methyl groups on the methyl-accepting chemotaxis
proteins (MCPs) was examined for Bacillus subtilis.
Attractants were found to cause an increase in the turnover
of methyl groups esterified to the MCPs, while repellents
caused a decrease. These reactions do not require CheW.
However, a cheW null mutant exhibits enhanced turnover in
unstimulated cells. Assuming that the turnover of methyl
groups on the MCPs reflects a change in the activity of CheA,
these results suggest that the activation of CheA via
chemoeffector binding at the receptor does not require CheW.
- Language of Publication
- English
- Unique Identifier
- 92325003
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- MeSH Heading (Major)
- Bacillus subtilis|DE/*PH; Bacterial Proteins|BI/*ME;
Chemotactic Factors|*PH
- MeSH Heading
- Butyrates|PD; Chemotaxis; Kinetics; Methionine|ME;
Methylation; Support, U.S. Gov't, P.H.S.; Tritium
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9193
- Country of Publication
- UNITED STATES
Record 10 from database: MEDLINE
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- Title
- Formation of N-(glutathion-S-methylene)-4-aminoazobenzene
following metabolic oxidation of the N-methyl group of the
carcinogen, N-methyl-4-aminoazobenzene.
- Author
- Ketterer B; Srai SK; Waynforth B; Tullis DL; Evans FE;
Kadlubar FF
- Address
-
- Source
- Chem Biol Interact, 1982 Feb, 38:3, 287-302
- Abstract
- A major biliary metabolite of the hepatocarcinogen,
N,N-dimethyl-4-aminoazobenzene (DAB), in the rat was
identified as N-(glutathion-S-methylene)-4-aminoazobenzene
(GS-CH2-AB). This conjugate was prepared synthetically by a
Mannich condensation of 4-aminoazobenzene (AB), formaldehyde
(CH2O) and glutathione (GSH) and has been characterized by
chemical analysis and by ultraviolet, visible and 13C-NMR
spectroscopy. The same conjugate was also formed in vitro by
incubating N-methyl-4-aminoazobenzene (MAB), NADPH, NADH and
GSH with rat hepatic microsomes. Evidence is presented that
GSH reacted with an intermediate resulting from a cytochrome
P-450-dependent oxidation of the N-methyl substituent. This
reactive intermediate is presumed to be either an N-methylol
or a methimine derivative of AB. The significance of this
detoxification mechanism is discussed. The presence of an
additional major aminoazo-dye GSH conjugate is also noted.
- Language of Publication
- English
- Unique Identifier
- 82137284
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- MeSH Heading (Major)
- p-Aminoazobenzene|AA/*ME; Azo Compounds|*ME;
Carcinogens|*ME
- MeSH Heading
- p-Dimethylaminoazobenzene|ME; Animal; Bile|ME; Comparative
Study; Glutathione|ME; In Vitro; Male; Metabolic
Detoxication, Drug; Microsomes, Liver|ME; Rats; Rats, Inbred
Strains; Support, Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0009-2797
- Country of Publication
- NETHERLANDS
Record 11 from database: MEDLINE
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- Title
- When is a trifluoromethyl group more lipophilic than a
methyl group? Partition coefficients and selected chemical
shifts of aliphatic alcohols and trifluoroalcohols.
- Author
- Muller N
- Address
-
- Source
- J Pharm Sci, 1986 Oct, 75:10, 987-91
- Abstract
- Octanol-water partition coefficients were determined for
12 trifluoromethylated aliphatic alcohols and their
unfluorinated counterparts. The latter values were derived
from measurements using the benzyl alcohol-water solvent
system after developing an appropriate correlation equation.
Incidentally, an empirical equation was found which allows
the partition coefficient of an unsubstituted alcohol to be
estimated given the molecular formula and boiling point.
Trifluorination strongly enhances lipophilicity only when
the trifluoromethyl group is in the alpha-position. The
enhancement is barely measurable for the beta- and gamma-(trifluoromethyl)
alcohols, while the delta- and epsilon-(trifluoromethyl)
compounds are considerably more hydrophilic than their
parent compounds. Chemical shift comparisons suggest that
the changes in relative lipophilicity are controlled
primarily by the inductive effect of the trifluoromethyl
group on the acidity-basicity of the hydroxyl group. New
synthetic procedures for obtaining some of the alcohols are
presented.
- Language of Publication
- English
- Unique Identifier
- 87086307
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- MeSH Heading (Major)
- Alcohols|*AN; Hydrocarbons, Fluorinated|*AN
- MeSH Heading
- Chemistry, Physical; Lipids; Nuclear Magnetic Resonance;
Solubility
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3549
- Country of Publication
- UNITED STATES
Record 12 from database: MEDLINE
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- Title
- Molecular structure of (m5 dC-dG)3: the role of the methyl
group on 5-methyl cytosine in stabilizing Z-DNA.
- Author
- Fujii S; Wang AH; van der Marel G; van Boom JH; Rich A
- Address
-
- Source
- Nucleic Acids Res, 1982 Dec, 10:23, 7879-92
- Abstract
- The hexamer (m5 dC-dG)3 has been synthesized and its
three-dimensional structure determined by a single crystal
X-ray diffraction analysis. The structure has been refined
to a final R value of 15.6% at 1.3 A resolution. The
molecule forms a left-handed Z-DNA helix which is similar to
the unmethylated Z-DNA structure. The presence of the methyl
group has resulted in slight changes in the twist angle
between successive base pairs and modification of some of
the interatomic contacts. Methylation of cytosine in the C5
position is associated with a relative destabilization of
the B-DNA structure and a stabilization through hydrophobic
bonding of the Z-DNA structure.
- Language of Publication
- English
- Unique Identifier
- 83116999
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- MeSH Heading (Major)
- Cytosine|*AA/AN; DNA|*; Oligodeoxyribonucleotides|*/CS;
Oligonucleotides|*/CS
- MeSH Heading
- Base Sequence; Models, Molecular; Nucleic Acid
Conformation; Support, Non-U.S. Gov't; Support, U.S. Gov't,
Non-P.H.S.; Support, U.S. Gov't, P.H.S.; X-Ray Diffraction
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0301-5610
- Country of Publication
- ENGLAND
Record 13 from database: MEDLINE
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- Title
- Methyl group turnover on methyl-accepting chemotaxis
proteins during chemotaxis by Bacillus subtilis.
- Author
- Thoelke MS; Casper JM; Ordal GW
- Address
- Department of Biochemistry, University of Illinois, Urbana
61801.
- Source
- J Biol Chem, 1990 Feb, 265:4, 1928-32
- Abstract
- The addition of attractant to Bacillus subtilis briefly
exposed to radioactive methionine causes an increase of
labeling of the methyl-accepting chemotaxis proteins. The
addition of attractant to cells radiolabeled for longer
times shows no change in the extent of methylation.
Therefore, the increase in labeling for the briefly labeled
cells is due to an increased turnover of methyl groups
caused by attractant. All amino acids gave enhanced
turnover. This turnover lasted for a prolonged time,
probably spanning the period of smooth swimming caused by
the attractant addition. Repellent did not affect the
turnover when added alone or simultaneously with attractant.
Thus, for amino acid attractants, the turnover is probably
the excitatory signal, which is seen to extend long into or
throughout the adaptation period, not just at the start of
it.
- Language of Publication
- English
- Unique Identifier
- 90130434
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- MeSH Heading (Major)
- Bacillus subtilis|DE/*ME; Chemotactic Factors|*ME;
Chemotaxis|*; Membrane Proteins|*ME
- MeSH Heading
- Amino Acids|PD; Kinetics; Methionine|ME; Methylation;
Radioisotope Dilution Technique; Support, U.S. Gov't, Non-P.H.S.;
Support, U.S. Gov't, P.H.S.; Tritium
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 14 from database: MEDLINE
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- Title
- Synthesis of benzyl
O-(2-O-methyl-beta-D-galactopyranosyl)-(1----3)-2-
acetamido-2-deoxy-beta-D-glucopyranoside [benzyl
2'-O-methyllacto-N-bioside I], and its higher saccharide
containing an O-(2-O-methyl-beta-D- galactopyranosyl)-(1----3)-2-acetamido-2-deoxy-beta-D-glucopyranosyl
group as a potential substrate for
(1---4)-alpha-L-fucosyltransferase.
- Author
- Sarkar AK; Jain RK; Matta KL
- Address
- Department of Gynecologic Oncology, Roswell Park Memorial
Institute, Buffalo, New York 14263.
- Source
- Carbohydr Res, 1990 Aug, 203:1, 33-46
- Abstract
- Treatment of benzyl O-beta-D-galactopyranosyl-(1----3)-2-acetamido-2-
deoxy-4,6-O-isopropylidene-beta-D-glucopyranoside with
tert-butylchlorodiphenylsilane afforded the
6'-O-tert-butyldiphenylsilyl ether, which was converted into
the 3',4'-O-isopropylidene derivative. Methylation and
subsequent removal of protecting groups afforded benzyl
O-(2-O-methyl-beta-D-galactopyranosyl)-
(1----3)-2-acetamido-2-deoxy-beta-D-glucopyranoside (7). The
trisaccharide methyl
O-(2-O-methyl-beta-D-galactopyranosyl)-(1----3)-O-(2-
acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----3)-beta-D-galactopyranosi
de (17) and the tetrasaccharide
O-(2-O-methyl-beta-D-galactopyranosyl)-(1----3)-O-(2-acetamido-2-deoxy-b
eta-D- glucopyranosyl)-(1----3)-O-beta-D-galactopyranosyl-(1----4)-D-glucopyran
ose (32), both containing the 2'-O-methyllacto-N-biose I
unit at the nonreducing end, were synthesized, and the
structures of 7, 17, and 32 were confirmed by 13C-n.m.r.
spectroscopy.
- Language of Publication
- English
- Unique Identifier
- 91029258
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- MeSH Heading (Major)
- Disaccharides|*CS; Fucosyltransferases|*ME;
Oligosaccharides|*CS
- MeSH Heading
- Carbohydrate Sequence; Molecular Sequence Data; Support,
U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-6215
- Country of Publication
- NETHERLANDS
Record 15 from database: MEDLINE
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- Title
- Biosynthesis of methylphosphomannosyl residues in the
oligosaccharides of Dictyostelium discoideum glycoproteins.
Evidence that the methyl group is derived from methionine.
- Author
- Freeze HH; Wolgast D
- Address
-
- Source
- J Biol Chem, 1986 Jan, 261:1, 135-41
- Abstract
- The phosphorylated oligosaccharides of Dictyostelium
discoideum contain methylphosphomannosyl residues which are
stable to mild-acid and base hydrolysis (Gabel, C. A.,
Costello, C. E., Reinhold, V. N., Kurtz, L., and Kornfeld,
S. (1984) J. Biol. Chem. 259, 13762-13769). Here we present
evidence that these methyl groups are derived from
[methyl-3H]methionine, in vivo and
[methyl-3H]S-adenosylmethionine in vitro. About 18% of the
macromolecules secreted from vegetative cells labeled with
[methyl-3H]methionine are released by digestion with
preparations of endoglycosidase/peptide N-glycosidase F. The
majority of the released molecules are sulfated, anionic
high mannose-type oligosaccharides. Strong acid hydrolysis
of the [3H]methyl-labeled molecules yields [3H]methanol with
kinetics of release similar to those found for the
generation of Man-6-P from chemically synthesized
methylphosphomannose methylglycoside. Treatment of the
[3H]methyl-labeled molecules with a phosphodiesterase from
Aspergillus niger which is known to cleave this
phosphodiester also releases [3H]methanol from a portion of
the oligosaccharides. In vitro incorporation of
[methyl-3H]S-adenosylmethionine into endogenous acceptors
found in membrane preparations shows that the [3H]methyl
group of the methylphosphomannose residues can be derived
from this molecule.
- Language of Publication
- English
- Unique Identifier
- 86085795
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- MeSH Heading (Major)
- Dictyostelium|*ME; Glycoproteins|*BI; Hexosephosphates|*BI;
Mannosephosphates|*BI; Methionine|*ME; Oligosaccharides|*BI
- MeSH Heading
- Chromatography, High Pressure Liquid; Chromatography, Ion
Exchange; Glycoside Hydrolases|ME; Hydrogen-Ion
Concentration; Kinetics; Methylation; Phosphorylation; S-Adenosylmethionine|ME;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 16 from database: MEDLINE
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- Title
- Effects of methyl-group acceptors on the regulation of
plasma cholesterol level in rats fed high cholesterol diets.
- Author
- Sugiyama K; Ohishi A; Siyu H; Takeuchi H
- Address
- Department of Applied Biological Chemistry, Faculty of
Agriculture, Shizuoka University, Japan.
- Source
- J Nutr Sci Vitaminol (Tokyo), 1989 Dec, 35:6, 613-26
- Abstract
- The effects of methyl-group acceptors such as glycine,
guanidinoacetic acid, and nicotinamide on cholesterol
metabolism and phosphatidylcholine(PC) biosynthesis were
investigated with rats fed a 25% casein diet containing
cholesterol with or without methionine supplement. The
effect of ethanolamine, an indirect methyl-group acceptor
via phosphatidylethanolamine(PE) formation, was also
compared with those of methyl-group acceptors. The
methyl-group acceptors and ethanolamine decreased or tended
to decrease plasma total cholesterol level when added to the
25% casein diet. These compounds also significantly
depressed the methionine-induced enhancement of plasma
cholesterol level. The activity of PE N-methyltransferase
was decreased by the addition of glycine, guanidinoacetic
acid, and nicotinamide, but not ethanolamine, to the
reaction mixture when assayed using the postmitochondrial
fraction of liver homogenate, suggesting that PE N-methyltransferase
activity can be depressed by glycine N-methyltransferase,
guanidinoacetic acid N-methyltransferase, and nicotinamide
N-methyltransferase systems. The PE N-methyltransferase
activity in liver microsomes, however, did not decrease in
response to the dietary addition of methyl-group acceptors.
The in vitro incorporation of [CH3-14C]methionine into PC of
liver slices was also significantly inhibited by the
addition of glycine and nicotinamide, but not
guanidinoacetic acid and ethanolamine, to the incubation
medium. It is suggested that methyl-group acceptors can
decrease plasma cholesterol level at least in part through
the depression of PC biosynthesis via PE N-methylation
pathway, and that the mechanism for the plasma
cholesterol-lowering effect of ethanolamine is different
from that of methyl-group acceptors.
- Language of Publication
- English
- Unique Identifier
- 90237922
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- MeSH Heading (Major)
- Cholesterol|*BL; Cholesterol, Dietary|*AD/PD;
Glycine|*AA/*PD; Niacinamide|*PD
- MeSH Heading
- Animal; Bile Acids and Salts|ME; Caseins|AD; Comparative
Study; Dietary Proteins|AD; Ethanolamines|PD; Feces;
Lipids|ME; Liver|AH/DE/ME; Male; Methionine|AD/PD;
Methyltransferases|ME; Microsomes, Liver|EN; Organ Weight|DE;
Rats; Rats, Inbred Strains
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0301-4800
- Country of Publication
- JAPAN
Record 17 from database: MEDLINE
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- Title
- Reduced methyl group acceptance of
1-beta-D-arabinofuranosylcytosine-containing DNA polymers.
- Author
- Grünwald S; Driever PH; Hoelzer D; Drahovsky D
- Address
- Zentrum der Biologischen Chemie, UniversitÂat Frankfurt,
F.R.G.
- Source
- Biochim Biophys Acta, 1988 Sep, 950:3, 366-73
- Abstract
- Previous studies have shown that
1-beta-D-arabinofuranosylcytosine (ara-C) can induce
differentiation of various malignant cells and that DNA
methylation patterns become altered under ara-C treatment of
those cells. The aim of this study was to investigate
whether this influence on DNA methylation is caused by a
direct effect of DNA-incorporated ara-C molecules on nuclear
DNA methylase. For this reason, we constructed various ara-C-substituted
DNA polymers and used them as substrates for highly purified
eukaryotic DNA methylase isolated from murine P815
mastocytoma cells. The ara-C incorporation into DNA polymers
was measured by either an ara-C-specific radioimmunoassay or
by use of radioactive-labelled ara-C during the synthesis of
those polymers. We found an inverse correlation between the
level of ara-C substitution of the DNA polymers and their
methyl group acceptance. Kinetic experiments performed with
ara-C-modified DNA polymers pointed out that the mode of
action of DNA methylase remains unaltered. DNA methylase is
neither detached nor fixed at an ara-C site, but is somehow
hindered in its enzymatic activity, probably by slowing down
the walking mechanism. Hence, the previously observed
hypermethylation of DNA of some eukaryotic cells, propagated
in the presence of ara-C, is apparently not due to a direct
effect of DNA-incorporated ara-C molecules on endogenous DNA
methylase.
- Language of Publication
- English
- Unique Identifier
- 89000788
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- MeSH Heading (Major)
- Cytarabine|*PD; DNA|*AA/*ME
- MeSH Heading
- Animal; Cell Line; DNA, Bacterial|ME; Kinetics;
Methylation; Mice; Polydeoxyribonucleotides|ME; Sarcoma,
Mast-Cell|EN; Site-Specific DNA Methyltransferase (Cytosine-Specific)|ME;
Structure-Activity Relationship; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 18 from database: MEDLINE
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- Title
- Effects of 5-azacytidine and methyl-group deficiency on
NAD(P)H: quinone oxidoreductase and glutathione S-transferase
in liver.
- Author
- Wagner G; Pott U; Bruckschen M; Sies H
- Address
- Institut fÂur Physiologische Chemie I, UniversitÂat DÂusseldorf,
Federal Republic of Germany.
- Source
- Biochem J, 1988 May, 251:3, 825-9
- Abstract
- Treatment with 5-azacytidine or dietary methyl-group
deficiency effected DNA hypomethylation in mouse liver. With
these treatments, NAD(P)H: quinone oxidoreductase (EC
1.6.99.2) and some glutathione S-transferase (EC 2.5.1.18)
activities were over-expressed, lactate dehydrogenase (EC
1.1.1.27) activity was unaffected and the level of
cytochrome P-450 was decreased. The 5-azacytidine induction
of NAD(P)H: quinone oxidoreductase was significantly
suppressed by puromycin, suggesting that increased enzyme
activity results from an elevated level of enzyme-protein
synthesis. Regulation at the transcriptional level was
revealed by a substantial increase in mRNA of NAD(P)H:
quinone oxidoreductase, as shown by Northern-blot analysis.
The enzyme pattern observed with 5-azacytidine and with the
(carcinogenic) dietary methyl-group deficiency resembles
that found in hepatic nodules.
- Language of Publication
- English
- Unique Identifier
- 88326222
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- MeSH Heading (Major)
- Azacitidine|*PD; Choline Deficiency|*ME; Glutathione
Transferase|*ME; Liver|DE/*EN; Methionine|*DF; Quinone
Reductases|*ME
- MeSH Heading
- Animal; DNA|ME; Electrophoresis, Agar Gel; Enzyme
Induction|DE; Male; Methylation; Mice; Mice, Inbred Strains;
Rats; Rats, Inbred Strains; RNA, Messenger|ME; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0264-6021
- Country of Publication
- ENGLAND
Record 19 from database: MEDLINE
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- Title
- Synthesis of an mRNA fragment of alanyl-tRNA synthetase
gene in Escherichia coli using the 6-methyl-3-pyridyl group
for protection of the imide functions of uridine and
guanosine.
- Author
- Welch CJ; Zhou XX; Chattopadhyaya J
- Address
-
- Source
- Acta Chem Scand [B], 1986 Nov, 40:10, 817-25
- Abstract
- The synthesis of 5'-GpGpUpGpU-3' is reported to
demonstrate the synthetic use of the 6-methyl-3-pyridyl
group for the protection of the O-4 and O-6 imide functions
of uridine and guanosine, respectively. The 2'- and
5'-hydroxyl functions of the key intermediates were
protected with two acid-labile groups:
3-methoxy-1,5-dicarbomethoxypentane-3-yl (MDMP) and
9-(4-octadecyloxyphenyl)xanthen-9-yl (C18Px), respectively.
The internucleotide phosphotriesters were protected with
2-chlorophenyl and the 9-fluorenylmethyl group was employed
for 3'-terminal phosphate protection.
- Language of Publication
- English
- Unique Identifier
- 87180488
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- MeSH Heading (Major)
- Alanine-tRNA Ligase|*GE; Amino Acyl-tRNA Ligases|*GE;
Escherichia coli|*EN/GE; Genes, Synthetic|*; RNA,
Bacterial|*BI/GE; RNA, Messenger|*BI/GE
- MeSH Heading
- Chemistry, Physical; Chromatography, High Pressure Liquid;
Guanosine|ME; Support, Non-U.S. Gov't; Uridine|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0302-4369
- Country of Publication
- DENMARK
Record 20 from database: MEDLINE
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- Title
- Disturbance of methyl group metabolism in alloxan-diabetic
sheep.
- Author
- Xue GP; Snoswell AM
- Address
-
- Source
- Biochem Int, 1985 Jun, 10:6, 897-905
- Abstract
- Alloxan-induced diabetes results in changes in the
activities of a number of enzymes related to methyl group
metabolism in sheep. Decreases in the activities of
phospholipid methyltransferase and betaine-homocysteine
methyltransferase in diabetic sheep liver indicate a reduced
rate of choline synthesis and oxidation. A 65-fold increase
in the activity of glycine methyltransferase and a 4-fold
rise in the activity of gamma-cystathionase in diabetic
sheep liver with elevated urinary excretion of cyst(e)ine
suggest that catabolism of the methyl group of methionine
and homocysteine was enhanced in the diabetic state.
- Language of Publication
- English
- Unique Identifier
- 85307017
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- MeSH Heading (Major)
- Diabetes Mellitus, Experimental|EN/*ME; Liver|*EN/ME;
Methyltransferases|*ME
- MeSH Heading
- Animal; Cystathionine beta-Synthase|ME; Cystathionine
gamma-Lyase|ME; Male; Pancreas|EN; Sheep; Support, Non-U.S.
Gov't; 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0158-5231
- Country of Publication
- AUSTRALIA
Record 21 from database: MEDLINE
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- Title
- Metabolism of S-adenosylmethionine in rat hepatocytes:
transfer of methyl group from S-adenosylmethionine by
methyltransferase reactions.
- Author
- Tsukada K; Abe T; Kuwahata T; Mitsui K
- Address
-
- Source
- Life Sci, 1985 Aug, 37:7, 665-72
- Abstract
- Treatment of rats with a methionine diet leads not only to
a marked increase of S-adenosylmethionine synthetase in
liver, but also to the increase of glycine, guanidoacetate
and betaine-homocysteine methyltransferases. The activity of
tRNA methyltransferase decreased with the increased amounts
of methionine in the diets. However, the activities of
phospholipids and S-adenosylmethionine-homocysteine
methyltransferases did not show any significant change. When
hepatocarcinogenesis induced by 2-fluorenylacetamide
progresses, the activities of glycine and guanidoacetate
methyltransferases in rat liver decreased, and could not be
detected in tumorous area 8 months after treatment. The
levels of S-adenosylmethionine in the liver also decreased
to levels of one-fifth of control animals at 8 months. The
uptake and metabolism of [methyl-3H]-methionine and -S-adenosylmethionine
have been investigated by in vivo and isolated hepatocytes.
The uptake of methionine and transfer of methyl group to
phospholipid in the cells by methionine were remarkably
higher than those by S-adenosylmethionine. These results
indicate that phospholipids in hepatocytes accept methyl
group from S-adenosylmethionine immediately, when it is
synthesized from methionine, before mixing its pool in the
cells.
- Language of Publication
- English
- Unique Identifier
- 85266984
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- MeSH Heading (Major)
- Liver|*EN; Methyltransferases|*ME; S-Adenosylmethionine|*ME
- MeSH Heading
- tRNA Methyltransferases|ME; Animal; Kinetics; Male;
Methionine Adenosyltransferase|ME; Rats; Rats, Inbred
Strains; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0024-3205
- Country of Publication
- ENGLAND
Record 22 from database: MEDLINE
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- Title
- Enhancing effect of a bay region methyl group on
tumorigenicity in newborn mice and mouse skin of
enantiomeric bay region diol epoxides formed
stereoselectively from methylchrysenes in mouse epidermis.
- Author
- Hecht SS; Amin S; Huie K; Melikian AA; Harvey RG
- Address
- Naylor Dana Institute for Disease Prevention, American
Health Foundation, Valhalla, New York 10595.
- Source
- Cancer Res, 1987 Oct, 47:20, 5310-5
- Abstract
- The stereochemistry of diol epoxide formation in mouse
epidermis upon topical application of
[3H]-1R,2R-dihydroxy-1,2-dihydro-5-methylchrysene
([3H]-5-MeC-1R,2R-diol) and [3H]-6-MeC-1R,2R-diol, and the
tumorigenicity in mouse skin and in newborn mice of the
R,S,S,R and S,R,R,S enantiomers of
1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene
(5-MeC-1,2-diol-3,4-epoxide), 5-MeC-7,8-diol-9,10-epoxide,
and 6-MeC-1,2-diol-3,4-epoxide were examined. Analysis of
tetraols and their derived tetraacetates present in mouse
epidermis, 2 h after application of [3H]-5-MeC-1R,2R-diol or
[3H]-6-MeC-1R,2R-diol, demonstrated greater than 90%
stereoselectivity in formation of
5-MeC-1R,2S-diol-3S,4R-epoxide and
6-MeC-1R,2S-diol-3S,4R-epoxide. Taken together with previous
data, these results demonstrate that there is a high degree
of stereoselectivity for formation of R,S,S,R enantiomers of
5-MeC- and 6-MeC-1,2-diol-3,4-epoxides in mouse skin. The
results of the tumorigenicity studies in mouse skin and in
newborn mice clearly demonstrated that
5-MeC-1R,2S-diol-3S,4R-epoxide was the most tumorigenic of
the diol epoxide enantiomers tested;
6-MeC-1R,2S-diol-3S,4R-epoxide was inactive. The results of
this study show that the high tumorigenicity of 5-MeC
compared to 6-MeC is due to the remarkable tumorigenic
activity of 5-MeC-1R,2S-diol-3S,4R-epoxide which, in
contrast to 6-MeC-1R,2S-diol-3S,4R-epoxide, has a methyl
group in the same bay region as the epoxide ring. We propose
that such methyl bay region diol epoxides of other
carcinogenic methylated polynuclear aromatic hydrocarbons
will also show unique tumorigenic properties.
- Language of Publication
- English
- Unique Identifier
- 88002004
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- MeSH Heading (Major)
- Animals, Newborn|*; Carcinogens|*; Chrysenes|*; Epoxy
Compounds|*; Ethers, Cyclic|*; Phenanthrenes|*; Skin|*DE;
Skin Neoplasms|*CI
- MeSH Heading
- Animal; Methylation; Mice; Stereoisomerism;
Structure-Activity Relationship; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-5472
- Country of Publication
- UNITED STATES
Record 23 from database: MEDLINE
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- Title
- Germination-initiation and inhibitory activities of L- and
D-alanine analogues for Bacillus subtilis spores.
Modification of methyl group of L- and D-alanine.
- Author
- Yasuda Y; Tochikubo K
- Address
-
- Source
- Microbiol Immunol, 1985, 29:3, 229-41
- Abstract
- The ability of 33 compounds of L-alanine analogues over a
wide range of concentrations to initiate germination of
Bacillus subtilis spores was determined, and the inhibitory
activity against L-alanine-initiated germination was
determined for the above compounds and 22 of their D- and
DL-isomers. Nineteen L-isomers were able to initiate the
germination. The maximum germination rate and the apparent
binding affinity of the germinant were obtained from
concentration-germination response curves. Not only
D-isomers but also L-isomers of many alanine analogues
showed inhibitory action on L-alanine-initiated germination.
The apparent binding affinity of an inhibitor was calculated
by Schild's method. D-Alanine, D-serine, glycine,
D-2-amino-n-butyric acid, D-cysteine, D-norvaline, and D-threonine
were competitive inhibitors for the L-alanine action.
Analysis of the relation between the structure of the side
chain of L- and D-alanine analogues and their apparent
affinity suggested that there are separate binding portions,
which differ in size and electrostatic nature, for
germination and for inhibition on the receptor. Certain L-alanine
analogues had a dualistic property of initiating germination
at low concentrations and inhibitory activity at higher
concentrations, i.e., autoinhibition. The autoinhibitory
phenomenon might be explained by the above postulation of
the presence of separate binding portions for germination
and for inhibition.
- Language of Publication
- English
- Unique Identifier
- 85239970
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- MeSH Heading (Major)
- Alanine|AA/AI/*PD; Bacillus subtilis|*PH
- MeSH Heading
- Spores, Bacterial|DE; Stereoisomerism; Structure-Activity
Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0385-5600
- Country of Publication
- JAPAN
Record 24 from database: MEDLINE
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- Title
- Effects of addition of a 2-methyl group to ethyl
nipecotates (beta-meperidines) on receptor affinities and
opiate agonist/antagonist activities.
- Author
- Lawson JA; Cheng A; DeGraw J; Frenking G; Uyeno E; Toll L;
Loew GH
- Address
- SRI International, Menlo Park, California 94025.
- Source
- J Med Chem, 1988 Oct, 31:10, 2015-21
- Abstract
- A series of
2-methyl-3-carbethoxy-3-(m-hydroxyphenyl)piperidine opiates
(13a-d) with N-substituent variations have been synthesized,
and their receptor affinities and in vivo agonist and
antagonist activities and energy-conformational profiles
have been determined. These are racemates of the alpha-epimer
at the C-2 position, with a methyl group cis to the 3-phenyl
group. One of the main goals of this study was to compare
the conformational and pharmacological behavior of these
2-methyl "beta-meperidine" analogues to their
2-desmethyl racemic counterparts (14a-c) previously reported
in the literature. The 2-desmethyl and 2-methyl analogues
were found to have very similar phenyl equatorial conformers
as their lowest energy forms with the addition of a 2-methyl
group diminishing conformational flexibility. The presence
of the 2-methyl group appears to diminish affinity at the mu-receptor
and also to somewhat diminish already weak antinociceptic
agonist activity. Given the similarity in lowest energy
conformation, this reduction is most likely caused by the
unfavorable interaction of the methyl group itself with a
local mu-receptor binding site. Superposition of the phenol
OH and protonated amine nitrogen NH of either 2-methyl
enantiomer of 13a in its lowest energy conformer with the
same OH and NH groups of metazocine, used as a high affinity
rigid analogue, leads to reasonable overlap. However, the N-substituents
and the piperidine and phenyl rings do not overlap in this
proposed pharmacophore, perhaps accounting for the rather
poor affinities found for these 3-phenylpiperidines and the
lack of N-substituent modulation of affinity and efficacy as
in fused ring opioids.
- Language of Publication
- English
- Unique Identifier
- 89011806
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- MeSH Heading (Major)
- Meperidine|*AA; Narcotic Antagonists|*PD; Receptors,
Opioid|*ME
- MeSH Heading
- Animal; Binding Sites; Male; Mice; Models, Molecular;
Nuclear Magnetic Resonance; Structure-Activity Relationship;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2623
- Country of Publication
- UNITED STATES
Record 25 from database: MEDLINE
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- Title
- Replacement of aromatic fluorine by a methoxy group during
reaction with methyl iodide in N,N-dimethylformamide
solvent.
- Author
- Chou TY; Vouros P; David M; Saha M; Giese RW
- Address
-
- Source
- Biomed Environ Mass Spectrom, 1987 Jan, 14:1, 23-7
- Abstract
- The DNA base uracil was derivatized with
pentafluorobenzoyl chloride, followed by methylation with
methyl iodide in the presence of N,N-dimethylformamide (DMF).
In addition to a 3-pentafluorobenzoyl-1-methyl derivative of
uracil, GC/MS analysis of the reaction mixture revealed the
formation of an unusual product, whose molecular weight was
12 U higher than that of the prior derivative. This
unexpected product has been identified as the
3-(para-methoxytetrafluorobenzoyl)-1-methyl derivative of
uracil. Isotopic labeling and related experiments have
revealed that the DMF solvent contributes the oxygen atom of
the methoxy group that replaces the para fluorine atom. This
work allowed a single derivative to be obtained for the
methylation reaction by changing the solvent to acetonitrile.
- Language of Publication
- English
- Unique Identifier
- 87185945
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- MeSH Heading (Major)
- Dimethylformamide|*AN; Hydrocarbons, Iodinated|*AN; Uracil|*AN
- MeSH Heading
- Acylation; Fluorine|AN; Mass Fragmentography; Methylation;
Protons; Solvents; Support, U.S. Gov't, Non-P.H.S.; Support,
U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0887-6134
- Country of Publication
- ENGLAND
Record 26 from database: MEDLINE
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- Title
- The synthesis of the neuropeptide Met-enkephalin and two
metabolic fragments labelled with 11C in the methionine
methyl group.
- Author
- NÁgren K; Ragnarsson U; LÁngström B
- Address
-
- Source
- Int J Rad Appl Instrum [A], 1986, 37:6, 537-9
- Abstract
- Starting from the corresponding N-benzyloxycarbonyl
S-benzyl homocysteine peptide benzyl esters, Met-enkephalin
and two metabolites, Gly-Phe-Met and Phe-Met, have been
labelled with 11C for application in positron emission
tomography in vivo. All labelling experiments were
accomplished in high radiochemical yields within 30-40 min
from start of the [11C]methyl iodide synthesis. Alkylations
with this reagent were performed in liquid ammonia, using
sodium to generate the free peptides with their reactive
sulphide anions, essentially as previously described for
[methyl-11C]methionine. The products were purified by liquid
chromatography (LC) to a radiochemical purity of 98% or
better.
- Language of Publication
- English
- Unique Identifier
- 87007637
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- MeSH Heading (Major)
- Enkephalin, Methionine|*CS/DU; Isotope Labeling|*
- MeSH Heading
- Carbon Radioisotopes; Peptide Fragments|CS; Tomography,
Emission-Computed
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0883-2889
- Country of Publication
- UNITED STATES
Record 27 from database: MEDLINE
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- Title
- Evidence for altered methionine methyl-group utilization
in the diabetic rat's brain.
- Author
- Dyer JR; Greenwood CE
- Address
- Dept. of Nutritional Sciences, University of Toronto,
Ontario, Canada.
- Source
- Neurochem Res, 1988 Jun, 13:6, 517-23
- Abstract
- The methionine (MET) derivative, S-adenosylmethionine
(SAM), provides methyl-groups for methylation reactions in
many neural processes. In rats made diabetic with
streptozotocin (SZ), brain SAM levels were generally lower
(10-20%) than in controls, with a constant decrease being
observed five weeks after onset of diabetes. This decrease
in SAM levels may be due to reduced precursor (MET)
availability because greatly elevating plasma MET
concentrations in SZ diabetic rats by dietary manipulation
increased their neural SAM concentrations to be
approximately or even greater than (5-20%) those of
controls. In contrast, neural levels of SAM's demethylated
product, S-adenosylhomocysteine (SAH), were reduced to a
greater extent (17-44%) than SAM levels in all groups of SZ
diabetic rats independent of their plasma MET concentrations
or brain SAM levels. This indicates that the decrease in SAH
levels is not simply due to substrate (SAM) restriction.
These changes in MET metabolites appear to be a general
effect of diabetes rather than a non-pancreatic side-effect
of SZ, because genetically diabetic BB Wistar rats also
exhibited reduced brain SAM (25%) and brain SAH (46%)
levels. These results indicate that methyl-groups from MET
are handled differently in the brain of the diabetic rat,
which considering the variety and importance of neural
methylation reactions, could have important consequences for
the diabetic.
- Language of Publication
- English
- Unique Identifier
- 88302594
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- MeSH Heading (Major)
- Brain|*ME; Diabetes Mellitus, Experimental|*ME;
Homocysteine|*AA; Methionine|*BL; S-Adenosylhomocysteine|*ME;
S-Adenosylmethionine|*ME
- MeSH Heading
- Administration, Oral; Animal; Caseins|AD; Diet; Female;
Male; Rats; Rats, Inbred Strains; Streptozocin; Support,
Non-U.S. Gov't; Time Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0364-3190
- Country of Publication
- UNITED STATES
Record 28 from database: MEDLINE
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- Title
- Chemotherapy of large bowel carcinoma--fluorouracil (FU) +
hydroxyurea (HU) vs. methyl-CCNU, oncovin, fluorouracil, and
streptozotocin (MOF-Strep). An Eastern Cooperative Oncology
Group study.
- Author
- Engstrom PF; MacIntyre JM; Schutt AJ; Douglass HO Jr
- Address
-
- Source
- Am J Clin Oncol, 1985 Oct, 8:5, 358-61
- Abstract
- In this prospective randomized study of initial
chemotherapy for advanced measurable metastatic large bowel
carcinoma, the response rate was 6/32 (19%) for FU + HU and
5/32 (16%) for MOF-Strep; the estimated median survival is
43 weeks for both treatments. Patients who received
MOF-Strep experienced substantially greater vomiting and
hematologic toxicity than patients who received FU + HU (p
less than 0.001).
- Language of Publication
- English
- Unique Identifier
- 86047676
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|TO/*TU; Colonic Neoplasms|*DT;
Rectal Neoplasms|*DT
- MeSH Heading
- Comparative Study; Drug Evaluation; Female;
Fluorouracil|AD/TO; Human; Hydroxyurea|AD/TO; Kidney
Diseases|CI; Male; Middle Age; Neutropenia|CI; Prospective
Studies; Random Allocation; Semustine|AD/TO; Streptozocin|AD/TO;
Support, U.S. Gov't, P.H.S.; Vincristine|AD/TO; Vomiting|CI
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0277-3732
- Country of Publication
- UNITED STATES
Record 29 from database: MEDLINE
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- Title
- In vivo oxidation of the methyl group of hepatic
5-methyltetrahydrofolate.
- Author
- Lumb M; Chanarin I; Deacon R; Perry J
- Address
- Haematology Section, Northwick Park Hospital, Harrow,
Middlesex.
- Source
- J Clin Pathol, 1988 Nov, 41:11, 1158-62
- Abstract
- Methionine given parenterally to rats caused rapid
disappearance of methyltetrahydrofolate from the liver and a
corresponding rise in tetrahydrofolate and
formyl-tetrahydrofolate concentrations. When
[14C]H3--H4folate was given, methionine caused an increased
[14C]0(2) excretion, indicating that oxidation of the methyl
group had occurred. Methionine was more effective than S-adenosylmethionine
at causing oxidation, but serine was ineffective. The lowest
dose of methionine to produce an effect was 0.5 mumol, which
is less than the daily dietary intake in a rat. The data
suggest that the concentration of methylfolate in rat livers
is controlled by the concentrations of methionine.
- Language of Publication
- English
- Unique Identifier
- 89093464
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- MeSH Heading (Major)
- Liver|DE/*ME; Tetrahydrofolates|*ME
- MeSH Heading
- Adenosine|AA/PD; Animal; Betaine|PD; Carbon Dioxide|ME;
Formyltetrahydrofolates|ME; Glycine|PD; Male; Methionine|PD;
Oxidation-Reduction; Rats; Rats, Inbred Strains; S-Adenosylmethionine|PD;
Serine|PD; Support, Non-U.S. Gov't; Thionucleosides|PD; Time
Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9746
- Country of Publication
- ENGLAND
Record 30 from database: MEDLINE
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- Title
- Fate of the methyl group during the conversion of
sterigmatocystin into O-methylsterigmatocystin and aflatoxin
B1 by cell-free preparations of Aspergillus parasiticus.
- Author
- Bhatnagar D; Cleveland TE
- Address
- USDA/ARS, Southern Regional Research Center, New Orleans,
LA 70179.
- Source
- Biochimie, 1988 Jun, 70:6, 743-7
- Abstract
- Cell-free extracts of fungal mycelia of two aflatoxin
non-producing isolates of Aspergillus parasiticus (SRRC 163
and SRRC 2043) were utilized for the study of enzyme
activities involved in the latter stages of aflatoxin
biosynthesis. The post-microsomal fractions (105,000 x g
supernatant) of both SRRC 163 and SRRC 2043 were able to
convert sterigmatocystin (ST) into O-methylsterigmatocystin
(OMST); whereas the microsomal (105,000 x g pellet)
preparation of only SRRC 163 was able to convert OMST into
aflatoxin B1 (AFB1). S-Adenosylmethionine (SAM) was the
primary substrate for the ST to OMST (methyltransferase)
enzymatic conversion; [3H]OMST of specific activity 0.93 Ci/mmol
was obtained in a reaction containing the [3H]SAM substrate
(specific activity 1 Ci/mmol). After the terminal enzymatic
conversion of OMST into AFB1, none of the radiolabel of the
methyl group from OMST was found in AFB1. It is postulated
that the methylation of ST may be required for subsequent
enzymatic oxidation of OMST to aflatoxin B1.
- Language of Publication
- English
- Unique Identifier
- 89000979
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- MeSH Heading (Major)
- Aflatoxins|*BI; Carcinogens|*ME; Sterigmatocystin|AA/*BI/*ME;
Xanthenes|*BI/*ME
- MeSH Heading
- Aspergillus|ME; Methylation; Oxidoreductases|ME;
Subcellular Fractions|EN
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0300-9084
- Country of Publication
- FRANCE
Record 31 from database: MEDLINE
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- Title
- The stereochemistry of the formation of the methyl group
in the glutamate mutase-catalysed reaction in Clostridium
tetanomorphum.
- Author
- Hartrampf G; Buckel W
- Address
-
- Source
- FEBS Lett, 1984 Jun, 171:1, 73-8
- Abstract
- The adenosylcobalamin-dependent enzyme glutamate mutase
from Clostridium tetanomorphum catalyses the reversible
rearrangement of (2S)-glutamate to (2S,3S)-3-
methylaspartate . In this conversion 6 carbon centers are
involved. The stereochemistry of 4 has been elucidated
whereas the formation of the methyl group from the methylene
group remains to be established. To solve this problem,
(2S,3R)- and (2S,3S)-[3,3-2H1,3H]glutamates were prepared
via the 2-oxo[3,3-2H2 or 3H] glutarates by incubation with
isocitrate dehydrogenase in deuterium oxide or tritiated
water. The labelled glutamates were fermented with growing
cells of C. tetanomorphum to butyrate and acetate. Butyrate
was further degraded to acetate in which methyl group over
90% of the tritium of the starting glutamate was retained.
The chirality of the acetates was determined with malate
synthase and fumarase. In both samples complete racemisation
was found. This result confirms the rule that racemisation
occurs in all adenosylcobalamin-dependent rearrangements in
which methyl groups are formed. A methylene radical as
intermediate could explain these observations. In a control
experiment inversion of configuration in the formation of
the methine group of (2S,3S)-3-methylaspartate from the
methylene group of (2S)-glutamate was confirmed. Glutamates
stereospecifically labelled at C-4 were synthesized from
chiral acetates via citrate.
- Language of Publication
- English
- Unique Identifier
- 84208856
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- MeSH Heading (Major)
- Amino Acid Isomerases|*ME; Clostridium|*EN
- MeSH Heading
- Carbon Radioisotopes|DU; Kinetics; Methylation; Nuclear
Magnetic Resonance; Stereoisomerism; Support, Non-U.S. Gov't;
Tritium|DU
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-5793
- Country of Publication
- NETHERLANDS
Record 32 from database: MEDLINE
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- Title
- Cold-sensitive ribosome assembly in an Escherichia coli
mutant lacking a single methyl group in ribosomal protein
L3.
- Author
- Lhoest J; Colson C
- Address
-
- Source
- Eur J Biochem, 1981 Dec, 121:1, 33-7
- Abstract
- Ribosomal protein methylation has been well documented but
its function remains unclear. We have examined this
phenomenon using an Escherichia coli mutant (prmB2), which
fails to methylate glutamine residue number 150 of ribosomal
protein L3. This mutant exhibits a cold-sensitive phenotype:
its growth rate at 22 degrees C is abnormally low in
complete medium. In addition, strains with this mutation
accumulate abnormal and unstable ribosomal particles; 50-S
and 30-S subunits are formed, but at a lower rate. Once
assembled, ribosomes with unmethylated L3 are fully active
by several criteria. (a) Protein synthesis in vitro with
purified 70-S prmB2 ribosomes is as active as wild-type
using either a natural (R17) or an artificial [poly(U)]
messenger. (b) The induction of beta-galactosidase in vivo
exhibits normal kinetics and the enzyme has a normal rate of
thermal denaturation. (c) These ribosomes are standard when
exposed in vitro to a low magnesium concentration or
increasing molarities of LiCl. Efficient methylation of L3
in vitro requires either unfolded ribosomes or a mixture of
ribosomal protein and RNA. We suggest that the L3-specific
methyltransferase may qualify as one of the postulated
'assembly factors' of the E. coli ribosome.
- Language of Publication
- English
- Unique Identifier
- 82117048
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- MeSH Heading (Major)
- Cold|*; Escherichia coli|*GE/ME; Mutation|*; Ribosomal
Proteins|*ME
- MeSH Heading
- Drug Stability; Glutamine|ME; Methylation; Proteins|BI;
Ribosomes|ME; RNA|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 33 from database: MEDLINE
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- Title
- The effect of the bay-region 12-methyl group on the
stereoselective metabolism at the K-region of
7,12-dimethylbenz[a]anthracene by rat liver microsomes.
- Author
- Yang SK; Fu PP
- Address
-
- Source
- Biochem J, 1984 Nov, 223:3, 775-82
- Abstract
- The enantiomers of a trans-5,6-dihydrodiol formed in the
metabolism of 7,12-dimethylbenz[a]anthracene by rat liver
microsomes (microsomal fractions) were resolved by chiral
stationary-phase high-performance liquid chromatography. The
major 7,12-dimethylbenz[a]anthracene trans-5,6-dihydrodiol
enantiomer and its hydrogenation product
5,6,8,9,10,11-hexahydro-trans-5,6-diol were found to have
5S,6S absolute configurations by the exciton chirality c.d.
method. The R,R/S,S enantiomer ratios of
7,12-dimethylbenz[a]anthracene trans-5,6-dihydrodiol formed
in the metabolism of 7,12-dimethylbenz[a]anthracene by liver
microsomes from untreated, 3-methylcholanthrene-treated and
phenobarbital-treated male Sprague-Dawley rats were found to
be 11:89, 6:94, and 5:95 respectively. These findings and
those reported previously on the metabolic formations of
trans-5,6-dihydrodiols from 7-methylbenz[a]anthracene and
12-methylbenz[a]anthracene suggest that the 12-methyl group
in 7,12-dimethylbenz[a]anthracene plays an important role in
determining the stereoselective metabolism at the K-region
5,6-double bond. Furthermore, the finding that formation of
5S,6S-dihydrodiol as the predominant enantiomer was not
significantly affected by the isoenzymic composition of
cytochrome P-450 present in microsomes prepared from the
livers of the rats pretreated with the different inducing
agents indicates that the stereoselectivity depends on the
substrate metabolized rather than on the precise nature of
the metabolizing-enzyme system.
- Language of Publication
- English
- Unique Identifier
- 85072043
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- MeSH Heading (Major)
- Microsomes, Liver|DE/*ME;
9,10-Dimethyl-1,2-benzanthracene|*ME
- MeSH Heading
- Animal; Chromatography, High Pressure Liquid; Circular
Dichroism; In Vitro; Male; Methylcholanthrene|PD; Molecular
Conformation; Rats; Rats, Inbred Strains; Spectrophotometry,
Ultraviolet; Stereoisomerism; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0264-6021
- Country of Publication
- ENGLAND
Record 34 from database: MEDLINE
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- Title
- Baker's antifol in combination with 5-fluorouracil and
methyl-CCNU in the treatment of metastatic colorectal
cancer: a Southwest Oncology Group Study (Protocol 7764).
- Author
- Shaw MT; Bonnet JD; Wilson H; Heilbrun LK
- Address
-
- Source
- Cancer Treat Rep, 1980 Feb, 64:2-3, 247-50
- Abstract
- Fifty-one previously untreated patients with metastatic
colorectal cancer were treated with a combination of
5-fluorouracil, methyl-CCNU, and Baker's antifol. Six of 34
fully evaluable patients achieved a response. There were no
apparent benefits obtained with this combination compared to
treatment with 5-fluorouracil alone.
- Language of Publication
- English
- Unique Identifier
- 81001569
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- MeSH Heading (Major)
- Colonic Neoplasms|*DT/PA; Fluorouracil|*AD; Folic Acid
Antagonists|*AD; Nitrosourea Compounds|*AD; Rectal Neoplasms|*DT/PA;
Semustine|*AD; Triazines|*AD
- MeSH Heading
- Adult; Aged; Blood Cell Count; Drug Administration
Schedule; Drug Therapy, Combination; Female; Human; Male;
Middle Age; Neoplasm Metastasis; Prognosis; Support, U.S.
Gov't, P.H.S.; Time Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0361-5960
- Country of Publication
- UNITED STATES
Record 35 from database: MEDLINE
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- Title
- Effect of methionine-loading on methyl group synthesis and
activation in rat brain and liver.
- Author
- Carl GF; Benesh FC; Hudson JL
- Address
-
- Source
- Biol Psychiatry, 1978 Dec, 13:6, 661-9
- Abstract
- Much greater increases in S-adenosylmethionine
concentrations are observed in the liver in response to
methionine-loading than in the brain due to differences in
the methionine adenosyltransferase activities in these
tissues. Liver methione adenosyltransferase exhibits a
bimodal saturation curve with a nonlinear Line-weaver-Burk
plot, indicating that high methionine concentrations are
required for saturation. In the brain the methionine
adenosyltransferase is saturated in vitro at a methionine
concentration less than the normal physiological
concentration. The increased S-adenosylmethionine
concentrations in the livers of methionine-treated rats also
account for the observed inhibition of
N5,N10-methylenetetrahydrofolate reductase activity in this
tissue. No inhibition of this enzyme is observed in the
brain of methionine treated animals. Nor are S-adenosylmethionine
concentrations increased significantly in brain. Serine
hydroxymethyltransferase activity responds to
methionine-loading by decreasing in brain and increasing in
liver.
- Language of Publication
- English
- Unique Identifier
- 79104098
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- MeSH Heading (Major)
- Brain|*EN; Liver|*EN; Methionine|*ME/*PD
- MeSH Heading
- Animal; Dose-Response Relationship, Drug; Glycine
Hydroxymethyltransferase|ME; Male; Methionine
Adenosyltransferase|ME; Methylation;
Methylenetetrahydrofolate Dehydrogenase|ME;
Methyltransferases|ME; Rats; S-Adenosylmethionine|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3223
- Country of Publication
- UNITED STATES
Record 36 from database: MEDLINE
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- Title
- Efficacy of MER immunotherapy when added to a regimen of
5-fluorouracil and methyl-CCNU following resection for
carcinoma of the large bowel. A Veterans Administration
Surgical Oncology Group report.
- Author
- Higgins GA; Donaldson RC; Rogers LS; Juler GL; Keehn RJ
- Address
-
- Source
- Cancer, 1984 Jul, 54:2, 193-8
- Abstract
- Two hundred four patients with a microscopically
incomplete resection for carcinoma of the colon or rectum
were accepted for study. All patients were treated with
5-fluorouracil and methyl-CCNU beginning about the second
postoperative week. Concurrent immunotherapy with the
methanol extraction residue of bacillus Calmette-Guérin (MER)
was randomly assigned to 103 patients. Treatment was
continued as long as acceptable to the patient, and until
clinical recurrence. Toxic reactions to the drug were not
increased by the addition of MER, and seldom were severe
enough to require the discrimination of therapy. No evidence
of improved survival was seen in treated patients. On the
contrary, survival in patients who experienced severe
reactions to treatment may have been impaired by MER, with
the period of impairment continuing after all adjuvant
therapy was stopped. Similar proportions of treated and
control deaths were attributable to residual or recurrent
disease.
- Language of Publication
- English
- Unique Identifier
- 84205277
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|*TU; BCG Vaccine|*TU;
Colonic Neoplasms|SU/*TH; Rectal Neoplasms|SU/*TH
- MeSH Heading
- Adult; Aged; Clinical Trials; Combined Modality Therapy;
Fluorouracil|AD/AE; Gastrointestinal Diseases|CI;
Hematologic Diseases|CI; Human; Immunotherapy; Male; Middle
Age; Palliative Care; Random Allocation; Risk; Semustine|AD/AE
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 37 from database: MEDLINE
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- Title
- Methyl group transfer from exogenous S-adenosylmethionine
on to plasma-membrane phospholipids without cellular uptake
in isolated hepatocytes.
- Author
- Van Phi L; Söling HD
- Address
-
- Source
- Biochem J, 1982 Sep, 206:3, 481-7
- Abstract
- At external concentration of 50 microM, L-methionine was
rapidly taken up by hepatocytes, whereas almost no S-adenosylmethionine
(SAM) was removed from the incubation medium. SAM did not
enter the intracellular water space but equilibrated with a
very small pool, which was most likely to be situated on the
external side of the plasma membrane. Methyl groups from
external L-methionine, but not from external SAM, were
incorporated into total and nuclear RNA. A significant
incorporation of methyl groups into phospholipids occurred
not only with methionine but also with SAM. After
subfractionation of hepatocytes it became evident that
methyl groups from SAM were mainly incorporated into
plasma-membrane phospholipids, and that phospholipid
methylation in other cellular compartments resulted from
contamination with plasma membrane. The pattern of
methylation of the various phospholipid species with SAM as
precursor was different from that obtained with
L-methionine. In contrast with external L-methionine,
external SAM did not enter the intracellular SAM pool.
According to these results a transport system for SAM does
not exist in rat hepatocytes, although methyl groups from
external SAM can be incorporated into plasma-membrane
phospholipids from the outside.
- Language of Publication
- English
- Unique Identifier
- 83074584
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- MeSH Heading (Major)
- Liver|CY/EN/*ME; Phospholipids|*ME; S-Adenosylmethionine|*ME
- MeSH Heading
- Animal; Cell Membrane|ME; In Vitro; Methylation;
Nucleotidases|ME; Rats; RNA|ME; Subcellular Fractions|ME;
Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2936
- Country of Publication
- ENGLAND
Record 38 from database: MEDLINE
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- Title
- Transfer of the methyl group of methionine to choline and
to tRNA in the honeybee Apis mellifica L.
- Author
- Tekitek A; Kerr SJ; Barbier M; Lederer E
- Address
-
- Source
- Biochimie, 1975, 57:10, 1185-8
- Abstract
- Contrary to some previous reports on the absence of
biological transmethylation reactions in some insect
species, the transfer of the methyl group of
methionine-methyl 14C leading to choline and to methylated
bases in tRNA was shown in the honeybee Apis mellifica. The
addition of antibiotics to the food of the insect does not
diminish the incorporation of radioactivity, proving that
intestinal bacteria are not responsible for the methylation
reactions observed.
- Language of Publication
- English
- Unique Identifier
- 76161481
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- MeSH Heading (Major)
- Bees|*ME; Choline|*ME; Lipids|*BI; RNA, Transfer|*ME; S-Adenosylmethionine|*ME
- MeSH Heading
- tRNA Methyltransferases|ME; Animal; Cytosine|ME; Fatty
Acids|BI; Guanine|ME; Methylation
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0300-9084
- Country of Publication
- FRANCE
Record 39 from database: MEDLINE
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- Title
- A phase II study of methyl CCNU in the treatment of solid
tumors and lymphomas: a Southwest Oncology Group study.
- Author
- Tranum BL; Haut A; Rivkin S; Weber E; Quagliana JM; Shaw
M; Tucker WG; Smith FE; Samson M; Gottlieb J
- Address
-
- Source
- Cancer, 1975 Apr, 35:4, 1148-53
- Abstract
- In March of 1972, the Southwest Oncology Group initiated a
Phase II study, No. 7200, utilizing methyl-CCNU in the
treatment of patients with solid tumors and lymphomas.
Initially, they received 200 mg/m2 orally as a single dose
every 6 weeks. The dose was subsequently reduced in
poor-risk patients to 150 mg/m2. There were 69 responses
noted in 675 evaluable patients (10%). The highest response
rates were noted in patients with Hodgkin's disease (13/31,
35%), malignant gliomas of the brain (8/29, 28%), anaplastic
carcinomas of the lung (5/20, 25%), and squamous cell
carcinomas of the head and neck (5/29, 17%). Squamous cell
tumors appeared to be more responsive than adenocarcinomas
(15% vs. 5%, respectively). Hematologic toxicity was
cumulative, and was influenced by dose and prior treatment.
There appeared to be no cross-resistance in patients
previously treated with alkylating agents. Methyl-CCNU is an
active antineoplastic agent. Further studies are indicated
in order to determine relative effectiveness.
- Language of Publication
- English
- Unique Identifier
- 75110582
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- MeSH Heading (Major)
- Antineoplastic Agents|AD/AE/*TU; Neoplasms|*DT;
Nitrosourea Compounds|AD/AE/*TU
- MeSH Heading
- Adenocarcinoma|DT; Administration, Oral; Brain
Neoplasms|DT; Carcinoma, Squamous Cell|DT; Cyclohexanes|AA/AD/TU;
Drug Evaluation; Drug Resistance; Glioma|DT; Head; Head and
Neck Neoplasms|DT; Hodgkin Disease|DT; Human; Lung
Neoplasms|DT; Lymphoma|DT; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 40 from database: MEDLINE
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- Title
- Phase I-II trial of methyl-GAG: a Southwest Oncology Group
Pilot Study.
- Author
- Knight WA 3d; Livingston RB; Fabian C; Costanzi J
- Address
-
- Source
- Cancer Treat Rep, 1979 Nov, 63:11-12, 1933-7
- Abstract
- One hundred and nine patients with advanced malignancy,
refractory to conventional therapy, were treated with a
weekly schedule of methyl-GAG. Ninety-one patients (83%)
were less than fully ambulatory. Sixty-five patients were
fully evaluable for response. There were two complete and
nine partial responses. An additional nine patients had
objective tumor regressions and were classified as improved.
The median duration of response was 5 months. Toxic effects
were primarily mucositis (17 patients) and nausea and
vomiting (14 patients). Sixty-seven patients had no
manifestations of drug toxicity. Responses observed in a
wide variety of solid tumors warrant further clinical
trials.
- Language of Publication
- English
- Unique Identifier
- 80110981
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- MeSH Heading (Major)
- Guanidines|*TU; Mitoguazone|AD/TO/*TU; Neoplasms|*DT/ME
- MeSH Heading
- Drug Evaluation; Female; Human; Male; Mucous Membrane|DE;
Polyamines|ME; Remission, Spontaneous; Support, U.S. Gov't,
P.H.S.; Vomiting|CI
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0361-5960
- Country of Publication
- UNITED STATES
Record 41 from database: MEDLINE
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- Title
- Phase II evaluation of diglycoaldehyde, VP-16-213, and the
combination of methyl-CCNU and beta-2'-deoxythioguanosine in
previously treated patients with colorectal cancer: an
Eastern Cooperative Oncology Group study (EST-1275).
- Author
- Douglass HO Jr; Lavin PT; Evans JT; Mittelman A; Carbone
PP
- Address
-
- Source
- Cancer Treat Rep, 1979 Aug, 63:8, 1355-7
- Abstract
- The Eastern Cooperative Oncology Group assessed the
activity of diglycoaldehyde (DGA), VP-16-213, and the
combination of methyl-CCNU and beta-2'-deoxythioguanosine in
previously treated patients with advanced colorectal cancer.
Objective responses were seen in two of 40 evaluable
patients receiving methyl-CCNU and
beta-2'-deoxythioguanosine and in one of 35 patients
receiving DGA. None of 33 patients responded to VP-16-213,
but one death related to sepsis and bone marrow failure
occurred. Survival of patients whose previous chemotherapy
included a nitrosourea was markedly shortened compared to
those who had not been exposed to nitrosoureas. With the
possible exception of DGA, further treatment of patients
with colorectal cancer with these therapies is not
warranted.
- Language of Publication
- English
- Unique Identifier
- 80001768
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- MeSH Heading (Major)
- Colonic Neoplasms|*DT; Deoxyguanosine|*AA/AD; Etoposide|*AD;
Inosine|*AA/AD; Nitrosourea Compounds|*AD/TU;
Podophyllotoxin|*AA; Rectal Neoplasms|*DT; Semustine|*AD;
Thionucleosides|*AD
- MeSH Heading
- Aldehydes|AD; Drug Evaluation; Drug Therapy, Combination;
Female; Human; Male; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0361-5960
- Country of Publication
- UNITED STATES
Record 42 from database: MEDLINE
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- Title
- Phase II study of 5-fluorouracil, methyl-CCNU, and
daunorubicin in colorectal cancer: a Cancer and Leukemia
Group B study.
- Author
- White LA Jr; Perry MC; Kardinal CG; Kennedy BJ; Weiss RB;
Carey RW
- Address
-
- Source
- Cancer Treat Rep, 1979 Feb, 63:2, 215-7
- Abstract
- The three-drug combination of 5-fluorouracil, methyl-CCNU,
and daunorubicin was evaluated in 38 patients with
unresectable or metastatic carcinoma of the colon. There
were five partial responses and one complete response for an
overall response rate of 16%. Although toxicity was
tolerable, daunorubicin failed to add to the 5-fluorouracil
and methyl-CCNU combination.
- Language of Publication
- English
- Unique Identifier
- 79189596
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- MeSH Heading (Major)
- Adenocarcinoma|*DT; Colonic Neoplasms|*DT; Daunorubicin|*AD/AE;
Fluorouracil|*AD/AE; Nitrosourea Compounds|*AD; Rectal
Neoplasms|*DT; Semustine|*AD/AE
- MeSH Heading
- Drug Evaluation; Drug Therapy, Combination; Female; Human;
Leukopenia|CI; Male; Middle Age; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0361-5960
- Country of Publication
- UNITED STATES
Record 43 from database: MEDLINE
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- Title
- The synthesis of D-ribofuranosyl derivatives of methyl
propiolate and a study of the activating influence of the
ester group in cycloaddition reactions.
- Author
- Buchanan JG; Edgar AR; Power MJ; Williams GC
- Address
-
- Source
- Carbohydr Res, 1977 May, 55:, 225-38
- Abstract
- 2,3,5-Tri-O-benzyl-D-ribofuranosyl bromide (17) has been
converted into methyl
3-(2,3,5-tri-O-benzyl-beta-D-ribofuranosyl) propiolate (8)
and its alpha anomer 10 in 21 and 42% yields, respectively,
by reaction with the silver salt of methyl propiolate.
Attempts to prepare 8 from (beta-D-ribofuranosyl)ethyne (1)
by standard methods were unsuccessful. The reactions of the
esters 8 and 10 and the ethyne 1 with several 1,3-dipoles
have been examined. With diazomethane, 8 and 10 gave the
pyrazole esters 20 and 28, respectively, whereast the ethyne
1 reacted more slowly to give a mixture of 23 (37%) and 26
(31%). The ester 10 was converted into the triazoles 32
(51%) and 36 (34%) by reaction with benzyl azide. Treatment
of the ester 10 with phenylhydrazine gave the pyrazolone 38
in 71% yield. A number of the products of dipolar addition
have been converted into new D-ribofuranosyl-pyrazoles and -triazoles
by hydrogenolysis.
- Language of Publication
- English
- Unique Identifier
- 77183523
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- MeSH Heading (Major)
- Ribose|*AA/CS
- MeSH Heading
- Chemistry; Stereoisomerism
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-6215
- Country of Publication
- NETHERLANDS
Record 44 from database: MEDLINE
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- Title
- Actions of N-methyl aspartate and its antagonist
aminophosphonovalerate on the A5 catecholamine cell group in
rat.
- Author
- Close JM; Neil JJ; Loewy AD
- Address
-
- Source
- Brain Res, 1982 Oct, 249:2, 393-6
- Abstract
- When N-methyl-D,L-aspartic acid was injected into the A5
catecholamine cell group of the rat, a dose-dependent
decrease in blood pressure and heart rate was obtained.
These cardiovascular changes were subsequently blocked by
the (-) and (+) isomers of the aspartate receptor blocker
2-amino-5-phosphonovalerate (2-amino-5-phosphonopentanoic
acid). The (-) isomer was 2-4 times more potent than the (+)
form.
- Language of Publication
- English
- Unique Identifier
- 83050081
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- MeSH Heading (Major)
- Aspartic Acid|*AA/PD; Brain|*DE; Receptors, Adrenergic|*DE;
Receptors, Cell Surface|*DE; Valine|*AA/PD
- MeSH Heading
- Animal; Blood Pressure|DE; Dose-Response Relationship,
Drug; Female; Heart Rate|DE; Male; Neurons|DE; Rats;
Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-8993
- Country of Publication
- NETHERLANDS
Record 45 from database: MEDLINE
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- Title
- Stereochemistry of a methyl-group rearrangement during the
biosynthesis of lanosterol.
- Author
- Phillips GT; Clifford KH
- Address
-
- Source
- Eur J Biochem, 1976 Jan, 61:1, 271-86
- Abstract
- 1. (3RS,6R)-[6-2H1,6-3H1,6-14C],
(3RS,6S)-[6-2H1,6-3H1,6-14C] and
(3RS)-[6-3H1,6-14C]mevalonolactones were synthesised from
R-[2H1,3H1,2-14C], S-[2H1,3H1,2-14C] and [3h1,2-14C]acetic
acids respectively. 2. Each mevalonate was converted into
cholesterol by a rat liver preparation. 3. Each cholesterol
specimen was converted into androsta-1,4-diene-3,17-dione by
incubation with Mycobacterium phlei in the presence of
2,2'.dipyridyl. Each specimen of
androsta-1,4-diene-3,17-dione was converted into
androsta-1,4-dien-3-one-17-ethylene ketail. 4. The samples
of androsta-1,4-dien-3-one-17-ethylene ketal were each
converted chemically into oestrones in which the methyl
group at C-18 is the only carbon atom that originated from
C-6 in mevalonolactone. 5. The oestrone from
(3RS)-[6-3H1,6-14C]mevalonolactone was oxidised chemically
to acetic acid which was converted into p-bromophenacyl
acetate and the 3H/14C ratio was measured. 6. There was no
overall loss of tritium from the methyl group of acetic
acid, as measured by determining the 3H/14C ratios of the p-bromophenacyl
esters, when the synthetic and degradative procedures 1 -- 5
were tested with [3H1,2-14C]acetic acid. 7. The oestrones
derived from the 6R and 6S-mevalonolactones were oxidised.
The chiralities of the resulting acetates were determined by
an established procedure whereby the acetates were converted
into 2S-malates which were examined for loss of tritium on
equilibration with fumarate hydratase. 8. The oestrone from
(3RS,6R)-[6-2H1,6-3H1,6-14C]mevalonate gave acetic acid
which was converted into 2S-malate that retained 68.6% of
its tritium after treatment with fumarate hydratase; the
configuration of this acetic acid was R. 9. The oestrone
from (3RS,6S)-E16-2H1,6-3H1,6-14C]mevalonate was oxidised to
acetic acid which was converted into 2S-malate that retained
31.9% of its tritium after treatment with fumarate hydratase;
the configuration of this acetic acid was S. 10. There was
no overall change in the configuration of a chiral methyl
group between C-6 of mevalonate and C-18 of oestrone. It is
cncluded that the intramolecular migration of a chiral
methyl group from C-15 in 2,3-oxidosqualene to C-13 in
lanosterol is stereospecific and occurs with overall
retention of configuration.
- Language of Publication
- English
- Unique Identifier
- 76092044
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- MeSH Heading (Major)
- Lanosterol|*BI
- MeSH Heading
- Acetic Acids|ME; Animal; Carbon Radioisotopes;
Cholesterol|BI; Deuterium; Fumarate Hydratase|ME; Isotope
Labeling; Liver|ME; Malates|ME; Mevalonic Acid|ME; Molecular
Conformation; Mycobacterium phlei|ME; Rats; Stereoisomerism;
Tritium
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 46 from database: MEDLINE
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- Title
- Selective and potent beta 2-adrenoceptor agents within the
tetrahydroisoquinoline class: effect of methyl substitution
at the benzylic carbon of the 1-(3,4,5-trimethoxybenzyl)
group of trimetoquinol.
- Author
- Sober DJ; Chang J; Fowble JW; Mukhopadhyay A; Feller DR;
Miller DD; Fairchild EH
- Address
-
- Source
- J Med Chem, 1981 Aug, 24:8, 970-4
- Abstract
- A systematic series of methyl (2 and 3) and dimethyl (4)
analogues of trimetoquinol (1) were synthesized and
evaluated for their beta 1 (atria) and beta 2 (trachea) and
adrenoceptor activities. Structural assignments for the
erythro (2) and the threo (3) diastereoisomers of
1-(3,4,5-trimethoxy-alpha-methylbenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline
were based on NMR spectra of the 6,7-dibenzyl precursors 15
and 16, respectively, and on the synthetic derivatives of
cis- and
trans-13-methyl-2,3-bis(benzyloxy)-9,10,11-trimethoxytetrahydroprotoberberine
(18 and 17). The rank order of beta 2-agonist activity for
these compounds was 3 greater than 1 greater than 2 greater
than 4. The rank order of activity as beta 1 agonists on the
guinea pig atria is 1 greater than 3 greater than 2, and 4
was inactive. The methylated analogues show selectivity for
beta 2 receptors in our preliminary pharmacological studies.
The threo isomer 3 is the most potent and selective beta 2
stimulant reported to date in the tetrahydroisoquinoline
class.
- Language of Publication
- English
- Unique Identifier
- 82122407
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- MeSH Heading (Major)
- Adrenergic beta-Agonists|*; Isoquinolines|*PD;
Tretoquinol|AA/*PD
- MeSH Heading
- Animal; Dose-Response Relationship, Drug; Guinea Pigs;
Heart|DE; Heart Rate|DE; In Vitro; Muscle Contraction|DE;
Muscle, Smooth|DE; Myocardial Contraction|DE; Support, U.S.
Gov't, P.H.S.; Trachea|DE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2623
- Country of Publication
- UNITED STATES
Record 47 from database: MEDLINE
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- Title
- Pathogenesis of subacute combined degeneration: a result
of methyl group deficiency.
- Author
- Scott JM; Dinn JJ; Wilson P; Weir DG
- Address
-
- Source
- Lancet, 1981 Aug, 2:8242, 334-7
- Abstract
- Four pairs of monkeys were maintained in an atmosphere of
nitrous oxide under conditions which had previously been
shown to produce subacute combined degeneration (SCD) of the
spinal cord. The diet of one of each pair was supplemented
with methionine. In every case the monkey with the
unsupplemented diet became ataxic at around 10 weeks and the
disorder progressed over a period of 2-3 weeks until the
animal was moribund. During this period there was no
detectable clinical change in the monkeys receiving
methionine supplementation. Microscopical examination of the
spinal cord and peripheral nerves of the unsupplemented
monkeys showed the classical changes of SCD. The
histological changes correlated with the clinical
observations. Sections form the methionine-supplemented
monkeys showed no change or only slight changes. These
results suggest that, in these animals, inability to
resynthesise methionine from homocysteine leads to SCD. It
seems probable that the primary lesion producing SCD in
human beings with pernicious anaemia is also inability to
maintain methionine biosynthesis.
- Language of Publication
- English
- Unique Identifier
- 81269412
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- MeSH Heading (Major)
- Disease Models, Animal|*; Methionine|*DF; Spinal Cord
Diseases|*ET/PA
- MeSH Heading
- Animal; Demyelinating Diseases|PA; Human; Macaca
fascicularis; Nitrous Oxide|PD; Spinal Cord|PA; Support,
Non-U.S. Gov't; Tetrahydrofolates|ME; Vitamin B 12|AI
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0140-6736
- Country of Publication
- ENGLAND
Record 48 from database: MEDLINE
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- Title
- Removal of the 9-methyl group of retinal inhibits signal
transduction in the visual process. A Fourier transform
infrared and biochemical investigation.
- Author
- Ganter UM; Schmid ED; Perez Sala D; Rando RR; Siebert F
- Address
- Institut fÂur Biophysik und Strahlenbiologie,
Albert-Ludwig-UniversitÂat Freiburg, FRG.
- Source
- Biochemistry, 1989 Jul, 28:14, 5954-62
- Abstract
- The photoreaction of opsin regenerated with
9-demethylretinal has been investigated by UV-vis
spectroscopy, flash photolysis experiments, and Fourier
transform infrared difference spectroscopy. In addition, the
capability of the illuminated pigment to activate the
retinal G-protein has been tested. The photoproduct, which
can be stabilized at 77 K, resembles more the lumirhodopsin
species, and only minor further changes occur upon warming
the sample to 170 K (stabilizing lumirhodopsin). UV-vis
spectroscopy reveals no further changes at 240 K
(stabilizing metarhodopsin I), but infrared difference
spectroscopy shows that the protein as well as the
chromophore undergoes further molecular changes which are,
however, different from those observed for unmodified
metarhodopsin I. UV-vis spectroscopy, flash photolysis
experiments, and infrared difference spectroscopy
demonstrate that an intermediate different from
metarhodopsin II is produced at room temperature, of which
the Schiff base is still protonated. The illuminated pigment
was able to activate G-protein, as assayed by monitoring the
exchange of GDP for GTP gamma S in purified G-protein, only
to a very limited extent (approximately 8% as compared to
rhodopsin). The results are interpreted in terms of a
specific steric interaction of the 9-methyl group of the
retinal in rhodopsin with the protein, which is required to
initiate the molecular changes necessary for G-protein
activation. The residual activation suggests a conformer of
the photolyzed pigment which mimics metarhodopsin II to a
very limited extent.
- Language of Publication
- English
- Unique Identifier
- 89375328
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- MeSH Heading (Major)
- Retinaldehyde|*/RE; Retinoids|*/RE
- MeSH Heading
- Animal; Fourier Analysis; G-Proteins|RE; In Vitro;
Molecular Structure; Photolysis; Rhodopsin|RE; Signal
Transduction|RE; Spectrophotometry, Infrared; Support, Non-U.S.
Gov't; Support, U.S. Gov't, P.H.S.; Vision
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 49 from database: MEDLINE
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- Title
- Methionine as methyl-group donor in the synthesis of
Mycobacterium avium envelope lipids, and its inhibition by
DL-ethionine, D-norleucine and DL-norleucine.
- Author
- David HL; Clavel Seres S; Clément F; Lazlo A; Rastogi N
- Address
- UnitÆe de la Tuberculose et des MycobactÆeries, Institut
Pasteur, Paris, France.
- Source
- Acta Leprol, 1989, 7 Suppl 1:, 77-80
- Abstract
- The radioactivity from 3H-methyl methionine was rapidly
incorporated into the surface lipids of Mycobacterium avium.
The transmethylation reaction was efficiently inhibited by
DL-ethionine, D-norleucine and DL-norleucine. The structure
of the outerlayer of the M. avium envelope was profoundly
altered in the bacteria treated with DL-norleucine.
- Language of Publication
- English
- Unique Identifier
- 89348745
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- MeSH Heading (Major)
- Membrane Lipids|*BI; Mycobacterium avium|DE/*ME/UL
- MeSH Heading
- Cell Wall|DE/ME/UL; Ethionine|PD; Methionine|ME;
Methylation; Microscopy, Electron; Norleucine|PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0001-5938
- Country of Publication
- SWITZERLAND
Record 50 from database: MEDLINE
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- Title
- 9-([2-hydroxy-1-(hydroxymethyl)ethoxy]methyl)guanine: a
selective inhibitor of herpes group virus replication.
- Author
- Field AK; Davies ME; DeWitt C; Perry HC; Liou R;
Germershausen J; Karkas JD; Ashton WT; Johnston DB; Tolman
RL
- Address
-
- Source
- Proc Natl Acad Sci U S A, 1983 Jul, 80:13, 4139-43
- Abstract
- 9-([2-Hydroxy-1-(hydroxymethyl)ethoxy]methyl)guanine
(2'-nor-2'-deoxyguanosine; 2'NDG) selectively inhibits the
replication of herpes group viruses. In cell culture studies
2'NDG was at least 10-fold more potent than acyclovir (ACV)
in inhibition of human cytomegalovirus replication and
Epstein-Barr virus-induced lymphocyte transformation and was
about as effective as ACV in inhibition of herpes simplex
viruses 1 and 2 and varicella zoster virus. Orally
administered 2'NDG was 6- to 50-fold more efficacious than
ACV in treating systemic or local HSV-1 infection or HSV-2
intravaginal infection in mice. The mode of action of 2'NDG
appears to involve phosphorylation by herpes simplex virus
thymidine kinase and subsequent phosphorylations by cellular
kinases to produce 2'NDG triphosphate, which is a potent
inhibitor of herpes virus DNA polymerase. Compared to ACV,
2'NDG was a more efficient substrate for HSV-1 thymidine
kinase (Vmax/Km for 2'NDG 30-fold higher than that of ACV),
whereas 2'NDG monophosphate is a more efficient substrate
for GMP kinase (Vmax/Km for 2'NDG monophosphate 492-fold
higher than that for ACV monophosphate). The combined effect
is more rapid production of the inhibitory triphosphate from
2'NDG than from ACV.
- Language of Publication
- English
- Unique Identifier
- 83247432
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- MeSH Heading (Major)
- Acyclovir|*AA/PD/TU; Antiviral Agents|*PD; DNA
Replication|*DE; Simplexvirus|DE/*GE
- MeSH Heading
- Animal; Cells, Cultured; Hela Cells|EN; Herpes Simplex|DT;
Human; Kidney; Phosphorylation; Rabbits; Thymidine Kinase|GE;
Virus Replication|DE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0027-8424
- Country of Publication
- UNITED STATES
Record 51 from database: MEDLINE
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- Title
- Chemical and enzymic studies on the characterization of
intermediates during the removal of the 14alpha-methyl group
in cholesterol biosynthesis. The use of 32-functionalized
lanostane derivatives.
- Author
- Akhtar M; Alexander K; Boar RB; McGhie JF; Barton DH
- Address
-
- Source
- Biochem J, 1978 Mar, 169:3, 449-63
- Abstract
- By using cell-free preparations of rat liver it was shown
that the removal of the 14alpha-methyl group (C-32) of
steroids containing either a delta7(8) or a delta8(9) double
bond is attended exclusively by the formation of the
corresponding 7,14- and 8,14-dienes respectively (structures
of types III and VIII). Cumulative evidence from a variety
of experimental approaches had led to the deduction that
delta8(14)-steroids are not involved as intermediates on the
major pathway of cholesterol biosynthesis. The metabolism of
[32-3H]lanost-7-ene-3beta,32-diol (structure of type I)
results in the formation of radioactive formic acid, no
labelled formaldehyde being formed. By using appropriately
labelled species of the compound (I) it was found that the
release of formic acid and the formation of
4,4-dimethylcholesta-7,14-dien-3beta-ol (strurcture of type
III) were closely linked processes, and that in the
conversion of compound (I) into compound (III),
3-beta-hydroxylanost-7-en-32-al (II) is an obligatory
intermediate. Both the conversion of
lanost-7-ene-3beta,32-diol (I) into
3beta-hydroxylanost-7-en-32-al (II) and the further
metabolism of the latter (II) to
4,4-dimethylcholesta-7,14-dien-3beta-ol (III) exhibited a
requirement for NADPH and O2. This suggests that the
oxidation of the 32-hydroxy group of compound (I) to the
aldehyde group of compound (II) does not occur by the
conventional alcohol dehydrogenase type of reaction, but may
proceed by a novel mechanism involving the intermediacy of a
gem-diol. A detailed overall pathway for the
14alpha-demethylation in cholesterol biosynthesis is
considered, and proposals about the mechanism of individual
steps in the pathway are made.
- Language of Publication
- English
- Unique Identifier
- 78165632
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- MeSH Heading (Major)
- Cholesterol|*BI; Lanosterol|*AA/IP/ME
- MeSH Heading
- Animal; Chemistry; Formic Acids|ME; Liver|ME; Male;
Molecular Conformation; NAD|ME; NADP|ME; Rats
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2936
- Country of Publication
- ENGLAND
Record 52 from database: MEDLINE
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- Title
- Alkyl substituent in place of the thymine methyl group
controls the A-X conformational bimorphism in poly(dA-dT).
- Author
- Vorlicková M; Sági J; Hejtmánková I; Kypr J
- Address
- Institute of Biophysics, Czechoslovak Academy of Sciences,
Brno.
- Source
- J Biomol Struct Dyn, 1991 Dec, 9:3, 571-8
- Abstract
- Circular dichroism studies of a family of poly(dA-y5dU)
polynucleotides (y = H, methyl, ethyl, propyl, butyl or
pentyl) were conducted in water-alcohol solutions containing
sodium or cesium counterions. The polynucleotides denatured
or adopted A- or X-DNA double helices depending on the
concentration and type of alcohol, type of counterions and
the length of the aliphatic substituent in place of the
thymine methyl group. Short aliphatic substituents and
sodium cations favored A-DNA while long aliphatic
substituents and cesium cations promoted X-DNA. This study
demonstrates delicacy of the conformational equilibrium of
poly(dA-dT) between the A- and X-DNA double helices which
depends on both intramolecular and intermolecular factors.
- Language of Publication
- English
- Unique Identifier
- 92273071
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- MeSH Heading (Major)
- DNA|*CH; Nucleic Acid Conformation|*; Poly dA-dT|*CH/CS
- MeSH Heading
- Alkylation; Cesium; Ethanol; Polydeoxyribonucleotides|CH;
Solutions; Trifluoroethanol
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0739-1102
- Country of Publication
- UNITED STATES
Record 53 from database: MEDLINE
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- Title
- 1H NMR analyses of methyl group-containing metabolites in
rat liver extracts--effects of starvation, anoxia, acute
glycerol and carbon tetrachloride treatment and chronic
ethanol administration on hepatic metabolism.
- Author
- Ling MF; Brauer M
- Address
- Department of Chemistry and Biochemistry.
- Source
- Physiol Chem Phys Med NMR, 1991, 23:4, 229-38
- Abstract
- 400 MHz 1H NMR spectroscopy was used to analyze methyl
group-containing metabolites in perchloric acid extracts of
livers of rats treated with carbon tetrachloride or fed with
ethanol-containing liquid diets, and sacrificed with carbon
dioxide anoxic euthanasia or pentobarbital euthanasia (with
or without 12-18 hour fasting). In all cases, coenzyme A was
detected using 1H NMR spectroscopy, but at higher levels for
chronic ethanol-treated rats. Propionate was also detected
in livers 6 hours after treatment with carbon tetrachloride.
The assignments of the 1H NMR resonances in a spectrum of
biological origin to these two metabolites have not been
previously reported. Another unusual metabolite,
1,2-propanediol, was also observed in dramatically elevated
levels in starved rats. The methyl groups for coenzyme A,
propionate, and 1,2-propanediol have 1H NMR chemical shifts
at 0.73 and 0.87 ppm, 1.18 ppm, and 1.14 ppm (from
tetramethylsilane) respectively. In addition to the above
mentioned resonances, glutamine, glutamate, proline,
acetate, leucine, alanine, lactate, ethanol, beta-hydroxybutyrate,
and valine were also observed in the 0.5-2.3 ppm methyl
region of the 1H NMR spectra. Biochemical changes were also
observed in these latter metabolites. beta-Hydroxybutyrate
was increased by chronic ethanol administration; this
increase was exacerbated by starvation. Alanine was
decreased by chronic ethanol administration. Acetate was
increased by chronic ethanol administration except when
glycerol was added to the liver or when the rat was starved.
We also observed an unassigned triplet at 0.81 ppm, and its
appearance seems to be correlated with that of
1,2-propanediol.
- Language of Publication
- English
- Unique Identifier
- 92253633
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- MeSH Heading (Major)
- Anoxia|*PP; Carbon Tetrachloride|*PD; Ethanol|*PD;
Glycerol|*PD; Liver|CH/DE/*ME; Starvation|*PP; Tissue
Extracts|*AN
- MeSH Heading
- Amino Acids|AN/ME; Animal; Coenzyme A|ME; Male; Nuclear
Magnetic Resonance; Propylene Glycols|ME; Rats; Rats, Inbred
Strains; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0748-6642
- Country of Publication
- UNITED STATES
Record 54 from database: MEDLINE
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- Title
- Addition of a methyl group changes both the catalytic
velocity and thermostability of the neutral protease from
Bacillus stearothermophilus.
- Author
- Takagi M; Imanaka T
- Address
- Department of Fermentation Technology, Faculty of
Engineering, Osaka University, Japan.
- Source
- FEBS Lett, 1989 Aug, 254:1-2, 43-6
- Abstract
- Specific activity was compared between wild-type (WT)
neutral protease from Bacillus stearothermophilus and mutant
protease (M1; Gly144 replaced by Ala144) with enhanced
thermostability. When casein was used as a substrate, M1
showed 1.5-times higher specific activity than that of WT.
In contrast, the specific activities of M1 for soluble
reduced lysozyme and insulin B chain were lower than those
of WT by 17.2 and 13.2%, respectively. After digestion of
the insulin A chain by these enzymes, the peptide products
were purified and the N-terminal amino acid sequences were
determined. WT enzyme cleaved insulin A chain at three
sites, whereas no digestion was observed with M1. Using
Z-Gly-Leu-NH2 as a substrate, the kinetic parameters were
determined. The Km values are nearly equal for both enzymes,
whereas the kcat of M1 (240 min-1) was much smaller compared
to the WT (830 min-1). The data indicate that the mutation
(addition of a methyl group) exerts an effect by changing
both the catalytic velocity and thermostability.
- Language of Publication
- English
- Unique Identifier
- 89378235
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- MeSH Heading (Major)
- Bacillus stearothermophilus|*EN; Peptide Hydrolases|GE/*IP
- MeSH Heading
- Amino Acid Sequence; Binding Sites; Comparative Study;
Enzyme Stability; Heat; Insulin|AN; Kinetics; Methylation;
Molecular Sequence Data; Mutation; Peptide Fragments|IP;
Thermolysin|AN
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-5793
- Country of Publication
- NETHERLANDS
Record 55 from database: MEDLINE
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- Title
- 1H nuclear-magnetic-resonance spectra of the methyl group
of the acetamido moiety and the structure of acid
glycosaminoglycans in solution.
- Author
- Scott JE; Heatley F
- Address
-
- Source
- Biochem J, 1979 Aug, 181:2, 445-9
- Abstract
- The 1H resonances of the methyl group in the acetamido
moiety of several types of glycosaminoglycans are reported
at 300 MHz in 2H2O. Dermatan sulphates with various L-iduronate/D-glucuronate
ratios are compared with chrondroitin sulphates with various
contents and positions of substitution of sulphate esters.
Hyaluronate oligomers are compared with
2-acetamido-2-deoxy-D-glucose, and with heparan sulphate and
keratan sulphate. The major determinant of the chemical
shift of the acetamido methyl resonance is the closeness of
approach between carboxy groups and the acetamido group, in
agreement with chemical evidence based on periodate-oxidation
kinetics.
- Language of Publication
- English
- Unique Identifier
- 80042293
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- MeSH Heading (Major)
- Glycosaminoglycans|*
- MeSH Heading
- Acetamides; Chemistry; Kinetics; Nuclear Magnetic
Resonance; Periodic Acid; Solubility; Structure-Activity
Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2936
- Country of Publication
- ENGLAND
Record 56 from database: MEDLINE
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- Title
- Phase II study of methyl-CCNU, vincristine,
5-fluorouracil, and streptozotocin in advanced colorectal
cancer. By the Gastrointestinal Tumor Study Group.
- Address
-
- Source
- J Clin Oncol, 1984 Jul, 2:7, 770-3
- Abstract
- In an attempt to confirm the previously reported response
rates with methyl-CCNU, vincristine, 5-fluorouracil, and
streptozotocin (MOF-strep) (34%) in advanced colorectal
cancer, the Gastrointestinal Tumor Study Group used the
identical treatment schedule in 40 good performance status
patients who had received no prior chemotherapy. Four
patients (10%) achieved an objective partial tumor response
and the median survival for all patients was 7.3 months. The
toxicity was evidenced by moderate nausea and vomiting and
myelosuppression with one treatment-related death. Based on
this trial further evaluation of MOF-strep for advanced
colorectal cancer cannot be recommended.
- Language of Publication
- English
- Unique Identifier
- 84241910
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|AE/*TU; Colonic Neoplasms|*DT;
Rectal Neoplasms|*DT
- MeSH Heading
- Drug Evaluation; Female; Fluorouracil|AD; Human; Liver
Neoplasms|DT/SC; Lung Neoplasms|DT/SC; Lymphatic Metastasis;
Male; Middle Age; Semustine|AD; Streptozocin|AD; Support,
U.S. Gov't, P.H.S.; Time Factors; Vincristine|AD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0732-183X
- Country of Publication
- UNITED STATES
Record 57 from database: MEDLINE
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- Title
- Methyl-GAG, ifosfamide, methotrexate and etoposide (MIME)
as salvage therapy for Hodgkin's disease and non-Hodgkin's
lymphoma. The Swedish Lymphoma Study Group.
- Author
- Enblad G; Glimelius B; Hagberg H; Lindemalm C
- Address
- Departments of Oncology, University of Uppsala, Akademiska
Hospital, Sweden.
- Source
- Acta Oncol, 1990, 29:3, 297-301
- Abstract
- One hundred and three patients with recurrent or
refractory Hodgkin's disease (HD) or non-Hodgkin's lymphoma
(NHL) treated with MIME (methyl-GAG, ifosfamide,
methotrexate, etoposide) were retrospectively studied.
Thirty-seven of the 44 patients with HD, 34/47 with
high-grade malignant and 9/12 with low-grade malignant NHL
were evaluable for response. Of the 37 evaluable patients
with HD, 16 (43%) achieved complete remission (CR) and 4
partial remission (PR), giving a total response rate of 54%.
Of the 34 evaluable patients with high-grade NHL, 5 achieved
CR and 8 PR, giving a response rate of 38%. Of 9 evaluable
patients with low-grade NHL, 2 achieved CR. The main
toxicity was leukopenia, thrombocytopenia and infections.
Twenty-six per cent of the patients developed septicaemia,
which was fatal in 6 cases (6%). We conclude that MIME as
salvage regimen can induce complete remissions in lymphoma
patients, particularly in HD with previous heavy treatment,
and that it is relatively well tolerated.
- Language of Publication
- English
- Unique Identifier
- 90303818
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|AE/*TU; Hodgkin
Disease|*DT; Lymphoma, Non-Hodgkin|*DT
- MeSH Heading
- Adult; Aged; Etoposide|AD; Female; Follow-Up Studies;
Human; Ifosfamide|AD; Male; Methotrexate|AD; Middle Age;
Mitoguazone|AD; Recurrence; Remission Induction;
Retrospective Studies
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0284-186X
- Country of Publication
- SWEDEN
Record 58 from database: MEDLINE
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- Title
- Central-nervous-system methyl-group metabolism in children
with neurological complications of HIV infection [see
comments]
- Author
- Surtees R; Hyland K; Smith I
- Address
- Department of Child Health, Institute of Child Health,
London, UK.
- Source
- Lancet, 1990 Mar, 335:8690, 619-21
- Abstract
- To assess methyl-group metabolism in the central nervous
system in infection with human immunodeficiency virus (HIV),
levels of 5-methyltetrahydrofolate, methionine, and S-adenosylmethionine
were measured by high-performance liquid chromatography in
cerebrospinal fluid (CSF) from six children with congenital
HIV infection and neurological complications. Total
neopterins were also measured, as a marker of macrophage
activation. In all six children concentrations of one or
more methyl-group carriers were lower than those in a
reference population of children, and all of the five in
whom CSF neopterins were measured had higher than normal
levels. Defective methylation may play a part in the
neurological damage caused by HIV infection.
- Language of Publication
- English
- Unique Identifier
- 90190086
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- MeSH Heading (Major)
- Biopterin|*AA/CF; Encephalitis|*CF/ET; HIV Seropositivity|*CF/CN/CO;
Methionine|*CF; S-Adenosylmethionine|*CF; Tetrahydrofolates|*CF
- MeSH Heading
- Child, Preschool; Human; Infant; Methylation; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0140-6736
- Country of Publication
- ENGLAND
Record 59 from database: MEDLINE
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- Title
- Absence of metabolic turnover of N-methyl groups in non-histone
and high mobility group chromosomal proteins.
- Author
- Byvoet P; Wiener DV
- Address
-
- Source
- Cell Biol Int Rep, 1983 Aug, 7:8, 587-91
- Abstract
- Turnover of N-methyl groups in non-histone chromosomal (NHC)
and high mobility group (HMG) proteins from chinese hamster
ovary cell nuclei was compared with that of the peptide
backbone. Cells grown with tritiated amino-acids and
methionine (Me-14C) were resuspended in unlabeled medium,
and aliquots removed at 4 time points. Halflives were
calculated from the decay of the respective specific
activities by the method of least squares. Ratios of
halflives for 14C and 3H calculated from the first order
rate decay curves of the specific activities were shown to
be close to unity.
- Language of Publication
- English
- Unique Identifier
- 84002308
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- MeSH Heading (Major)
- Chromosomal Proteins, Non-Histone|*ME
- MeSH Heading
- Animal; Cell Line; Comparative Study; Female; Half-Life;
Hamsters; Histones|ME; Methylation; Ovary; Support, U.S.
Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0309-1651
- Country of Publication
- ENGLAND
Record 60 from database: MEDLINE
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- Title
- Acyloxy neighboring-group participation in the
acid-catalyzed cleavage of methyl
2,3-anhydro-beta-D-ribofuranoside.
- Author
- Hollenberg DH; Watanabe KA; Fox JJ
- Address
-
- Source
- Carbohydr Res, 1975 Jul, 42:2, 241-9
- Abstract
- The reaction of methyl 2,3-anhydro-beta-D-ribofuranoside
with hydrogen bromide in an acetic acid-acetic anhydride
solution leads to the formation of methyl
2,3-di-O-acetyl-5-bromo-5-deoxy-alpha,beta-D-xylofuranoside.
Similar treatment of methyl
2,3-anhydro-5-O-benzoyl-beta-D-robofuranoside provided
methyl
2-O-acetyl-3-O-benzoyl-5-bromo-5-deoxy-alpha,beta-D-xylofuranosides.
The position of halogen substitution was ascertained by
hydrogenolysis to the resultant 5-deoxy sugars, which were
characterized by their n.m.r. spectra. Confirmation of the
structural assignment for methyl
2-O-acetyl-3-O-benzoyl-5-deoxy-alpha,beta-D-xylofuranoside
was obtained by synthesis from
1,2-O-isopropylidene-alpha-D-xylofuranose. The formation of
the 5-bromo derivatives under the reported conditions
probably occurred through the intermediacy of the
3,5-acyloxonium ions. Similar conversions were observed when
the starting compound was treated with hydrogen chloride,
acetyl bromide, or acetyl chloride in acetic acid-acetic
anhydride solutions.
- Language of Publication
- English
- Unique Identifier
- 75185399
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- MeSH Heading (Major)
- Deoxy Sugars|*CS; Methylglycosides|*; Ribose|*AA; Xylose|*AA
- MeSH Heading
- Bromine; Chromatography; Chromatography, Thin Layer;
Methods; Nuclear Magnetic Resonance; Silicon Dioxide;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-6215
- Country of Publication
- NETHERLANDS
Record 61 from database: MEDLINE
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- Title
- An Eastern Cooperative Oncology Group evaluation of
combinations of methyl-CCNU, mitomycin C, Adriamycin, and
5-fluorouracil in advanced measurable gastric cancer (EST
2277).
- Author
- Douglass HO Jr; Lavin PT; Goudsmit A; Klaassen DJ; Paul AR
- Address
-
- Source
- J Clin Oncol, 1984 Dec, 2:12, 1372-81
- Abstract
- In a prospectively randomized trial, patients with
advanced locally recurrent or metastatic gastric
adenocarcinoma were randomized to receive 5-fluorouracil
(5-FU) and methyl-CCNU; 5-FU, Adriamycin (Adria
Laboratories, Columbus, Ohio), and methyl-CCNU; 5-FU,
Adriamycin, and mitomycin C; or Adriamycin and mitomycin C
alone. One hundred eighty-three previously untreated
evaluable patients were randomized among the four arms. An
additional 39 patients previously treated with 5-FU, were
assigned to treatment directly to Adriamycin and mitomycin
C. Response rates were 14%, 29%, 39%, and 29%, respectively,
among previously untreated patients and 21% for Adriamycin
and mitomycin C among previously treated patients.
5-Fluorouracil, Adriamycin, and mitomycin C, the arm
containing the largest number of responders (18), was the
combination associated with the longest median survival. A
larger proportion of patients in this arm survived one year
or more. In addition, the 5-FU, Adriamycin, and mitomycin C
program had the lowest rate of severe or worse toxicity of
any of the treatments and was effective in patients who were
less than fully ambulatory and in those who had lost weight.
5-Fluorouracil, Adriamycin, and mitomycin C appear to be a
likely combination to be considered in a surgical adjuvant
program.
- Language of Publication
- English
- Unique Identifier
- 85082210
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- MeSH Heading (Major)
- Adenocarcinoma|*DT; Antineoplastic Agents,
Combined|*AD/AE; Stomach Neoplasms|*DT
- MeSH Heading
- Adult; Aged; Doxorubicin|AD; Female; Fluorouracil|AD;
Human; Male; Middle Age; Mitomycins|AD; Semustine|AD;
Support, U.S. Gov't, P.H.S.
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0732-183X
- Country of Publication
- UNITED STATES
Record 62 from database: MEDLINE
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- Title
- Semisynthesis of A23187 (calcimycin) analogs. II.
Introduction of a methyl group on the benzoxazole ring.
- Author
- Prudhomme M; Dauphin G; Guyot J; Jeminet G
- Address
-
- Source
- J Antibiot (Tokyo), 1984 Jun, 37:6, 627-34
- Abstract
- Semisynthesis of two demethylamino A23187 with a methyl
group in the 4- or 5-position on the benzene ring were
carried out via the cleavage of A23187 oxazole ring and
rebuilding of modified benzoxazoles. These compounds were
shown to release Ca++ and MG++ from mitochondria and to keep
part the antibacterial activity of the natural metabolite.
- Language of Publication
- English
- Unique Identifier
- 84264085
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- MeSH Heading (Major)
- Calcimycin|AA/*CS/TO
- MeSH Heading
- Comparative Study; Indicators and Reagents; Microbial
Sensitivity Tests; Nuclear Magnetic Resonance;
Structure-Activity Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-8820
- Country of Publication
- JAPAN
Record 63 from database: MEDLINE
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- Title
- Rotational frequencies of methyl group tunneling.
- Author
- Barlow MJ; Clough S; Horsewill AJ; Mohammed MA
- Address
- Department of Physics, University of Nottingham, UK.
- Source
- Solid State Nucl Magn Reson, 1992 Nov, 1:4, 197-204
- Abstract
- Methyl tunnel frequencies, measured at 4 K, are found to
be 455 +/- 8 kHz in methyl malonamide and 496 +/- 8 kHz in
methyl ethyl ketone. The first is unaffected by deuteration
of the amide groups. Measurements of the temperature
dependence of the spin lattice relaxation time are also
reported for methyl malonamide and a further test is made of
a previously reported correlation between tunnel frequency
and the temperature of the T1 minimum. The measurements are
in good agreement with the universal correlation curve.
- Language of Publication
- English
- Unique Identifier
- 95135862
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- MeSH Heading (Major)
- Nuclear Magnetic Resonance|*MT
- MeSH Heading
- Butanones|CH; Malonates|CH; Methylation; Models, Chemical;
Molecular Structure; Rotation; Support, Non-U.S. Gov't;
Temperature; Thermodynamics
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0926-2040
- Country of Publication
- NETHERLANDS
Record 64 from database: MEDLINE
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- Title
- Mitoxantrone, cisplatin, and methyl-glyoxal
bis-guanylhydrazone chemotherapy for refractory malignant
lymphoma: a Southwest Oncology Group phase II trial.
- Author
- Dana B; Dahlberg S; Schnitzer B; Kjeldsberg CR; Jones SE;
Carden J; Mundis R; Tranum B
- Address
- Oregon Health Sciences University.
- Source
- Invest New Drugs, 1989 Jul, 7:2-3, 247-50
- Abstract
- A phase II trial of combination chemotherapy with
mitoxantrone, cisplatin, and methyl-glyoxal
bix-guanylhydrazone (MGBG) was conducted in 32 patients with
unfavorable histology malignant lymphoma. All patients had
relapsed after only one prior chemotherapy regimen
(CHOP--56%; mBACOD--28%). There were three complete and
eight partial responses (overall response rate--34%) among
32 eligible patients. The median duration of remission was
6.0 months. Severe granulocytopenia was common, with 19/32
patients (63%) suffering life-threatening, and 1/32 (3%)
suffering fatal, granulocytopenia. We conclude that
mitoxantrone-cisplatin-MGBG has modest activity as salvage
treatment in malignant lymphoma patients, but produces
severe toxicity.
- Language of Publication
- English
- Unique Identifier
- 90008033
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|AE/*TU; Lymphoma|*DT
- MeSH Heading
- Adolescence; Adult; Aged; Aged, 80 and over; Cisplatin|AD/AE;
Drug Evaluation; Female; Human; Male; Middle Age;
Mitoguazone|AD/AE; Mitoxantrone|AD/AE; Support, U.S. Gov't,
P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0167-6997
- Country of Publication
- UNITED STATES
Record 65 from database: MEDLINE
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- Title
- Effect of dietary methyl group deficiency on folate
metabolism in rats.
- Author
- Horne DW; Cook RJ; Wagner C
- Address
- Department of Biochemistry, Vanderbilt University School
of Medicine, Nashville, TN 37212.
- Source
- J Nutr, 1989 Apr, 119:4, 618-21
- Abstract
- The carcinogenic effects of methyl-deficient, amino
acid-defined diets have been attributed to alterations in
cellular methylation reactions. These diets contain no
choline, and methionine is replaced by homocysteine. Hence,
all methyl groups needed for methionine biosynthesis with
subsequent formation of S-adenosylmethionine and polyamines
must be formed de novo utilizing folate-dependent reduction
of one-carbon units. In rats fed the methyl-deficient diet,
there was a marked decrease in total liver folate levels.
This decrease was apparent in the levels of the individual
forms of folate: 10-HCO-H4folate, 5-HCO-H4folate,
5-CH3-H4folate and H4folate. The percent of the total folate
pool made up by 5-CH3-H4folate did not change, however,
until after the rats had been fed the methyl-deficient diet
for 4 wk, and then an increase was seen. After the
methyl-deficient rats were switched to a nutritionally
adequate control diet containing methionine and choline, all
values rapidly reversed. Increased use of folate for methyl
group biosynthesis may be responsible for the loss of
folates from the liver.
- Language of Publication
- English
- Unique Identifier
- 89199129
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- MeSH Heading (Major)
- Choline Deficiency|*ME; Diet|*; Folic Acid|*ME; Liver|*ME;
Methionine|*DF
- MeSH Heading
- Amino Acids|AD; Animal; Chromatography, High Pressure
Liquid; Leucovorin|AA/ME; Male; Methylation; Rats; Rats,
Inbred F344; Support, Non-U.S. Gov't; Support, U.S. Gov't,
Non-P.H.S.; Support, U.S. Gov't, P.H.S.;
Tetrahydrofolates|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3166
- Country of Publication
- UNITED STATES
Record 66 from database: MEDLINE
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- Title
- Synthesis and kinetic studies of protease substrates
containing the 1-methyl-6-aminoquinolinium ion as a
fluorogenic leaving group.
- Author
- Andrade Gordon P; Gordon D; Brynes PJ; Wu CW
- Address
-
- Source
- J Med Chem, 1984 Sep, 27:9, 1166-70
- Abstract
- Several sensitive substrates for porcine pancreatic
elastase, chymotrypsin, and trypsin were prepared that
utilize the permanently charged, fluorogenic cation
1-methyl-6-aminoquinoline (MAQ+) as the leaving group.
Kinetic rates for the hydrolysis of substrates were
determined fluorimetrically and compared with analogues
having 6-aminoquinoline (6-AQ) as an uncharged leaving
group. It was found that substrates containing the
quaternized leaving group generally have a higher kcat/Km
ratio. An exception to this trend was noted with a trypsin
substrate, Bz-DL-Arg-MAQ+. During the course of this
investigation, several significant advantages of the MAQ+
ion as a fluorogenic leaving group in protease substrates
were found: (a) its appearance can be measured
fluorimetrically using wavelengths of light that result in
its maximal fluorescence, while under these conditions, the
unhydrolyzed substrate is essentially nonfluorescent, (b) it
confers a high degree of water solubility to hydrophobic
peptides, thereby eliminating the need for organic
cosolvents to dissolve substrates, and (c) quaternized
substrates can be prepared readily and in good yield from
the corresponding 6-(peptidylamido)quinolines. These
positively charged synthetic fluorogenic substrates are,
therefore, useful probes for investigating the steric and
electronic properties of the active-site environment of
proteolytic enzymes.
- Language of Publication
- English
- Unique Identifier
- 84292228
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- MeSH Heading (Major)
- Aminoquinolines|*CS; Peptide Hydrolases|*AN/ME
- MeSH Heading
- Chymotrypsin|AN; Kinetics; Pancreas|EN;
Pancreatopeptidase|AN; Spectrometry, Fluorescence; Support,
U.S. Gov't, P.H.S.; Trypsin|AN
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2623
- Country of Publication
- UNITED STATES
Record 67 from database: MEDLINE
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- Title
- Preliminary assignments of the aromatic and some methyl
group resonances of the 1H-NMR spectrum of the oxidized form
of uteroglobin. Application to the interaction of oxidized
uteroglobin with progesterone.
- Author
- Jamin N; Roy P; Fridlansky F; Delepierre M; Milgrom E;
Roques BP; Mornon JP
- Address
- UniversitÆe RenÆe Descartes, DÆepartment de Chimie
organique, Paris.
- Source
- Eur J Biochem, 1989 Jul, 183:1, 219-26
- Abstract
- Two-dimensional NMR methods have been used to assign
aromatic and methyl group resonances in the 1H-NMR spectrum
of oxidized uteroglobin. Assignments to specific amino acids
are based on X-ray-determined structures of two crystal
forms (C222(1) and P2(1] and on an energy-minimized X-ray
structure of the C222(1) form of uteroglobin. These
preliminary assignments are sufficient to probe the
interaction of oxidized uteroglobin with progesterone in
solution. The protein global structure is unmodified but
some direct or indirect conformational changes are induced
in the H1H4(H1'H4') pockets and close to Phe28 by
progesterone.
- Language of Publication
- English
- Unique Identifier
- 89325339
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- MeSH Heading (Major)
- Glycoproteins|*AN; Progesterone|*AN; Uteroglobin|*AN
- MeSH Heading
- Binding Sites; Energy Transfer; Female; Human; Methylation;
Nuclear Magnetic Resonance; Oxidation-Reduction; Support,
Non-U.S. Gov't; Uterus|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 68 from database: MEDLINE
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- Title
- Efficacy of prolonged intermittent therapy with combined
5-fluorouracil and methyl-CCNU following resection for
carcinoma of the large bowel. A Veterans Administration
Surgical Oncology Group report.
- Author
- Higgins GA Jr; Amadeo JH; McElhinney J; McCaughan JJ;
Keehn RJ
- Address
-
- Source
- Cancer, 1984 Jan, 53:1, 1-8
- Abstract
- This prospective evaluation of 5-FU and methyl-CCNU
administered in combination to patients with curative
surgery for histologically proved colorectal adenocarcinoma
is based upon 645 patients randomized between August 1973
and July 1979. Beyond the requirement that the resection be
clinically and microscopically complete, patients were not
stratified prior to random treatment assignment to surgery
alone or surgery followed by adjuvant chemotherapy. Drug
therapy consisted of discrete 5-day courses administered at
7-week intervals, start to start. Toxic reactions were
reported in association with 40% of courses. In 10% of
patients with hematologic toxicity, the reactions were
sufficiently severe to require the suspension or
discontinuation of treatment. Treated patients experienced a
slightly more favorable survival than did controls. However,
the advantage was seen only in the 216 patients (34% of
total) with one to four positive lymph nodes in the resected
specimen. Similar proportions of treated and control deaths
were attributed to residual or recurrent disease.
- Language of Publication
- English
- Unique Identifier
- 84081728
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- MeSH Heading (Major)
- Adenocarcinoma|*DT/SU; Antineoplastic Agents, Combined|*TU;
Colonic Neoplasms|*DT/MO/SU
- MeSH Heading
- Adult; Aged; Clinical Trials; Combined Modality Therapy;
Fluorouracil|AD; Gastrointestinal Diseases|CI; Hematologic
Diseases|CI; Human; Middle Age; Random Allocation; Rectal
Neoplasms|DT/SU; Recurrence; Semustine|AD
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 69 from database: MEDLINE
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- Title
- Efficacy of prolonged intermittent therapy with combined
5-FU and methyl-CCNU following resection for gastric
carcinoma. A Veterans Administration Surgical Oncology,
Group report.
- Author
- Higgins GA; Amadeo JH; Smith DE; Humphrey EW; Keehn RJ
- Address
-
- Source
- Cancer, 1983 Sep, 52:6, 1105-12
- Abstract
- This prospective evaluation of 5-fluorouracil (5-FU) and
methyl-CCNU administered in combination to patients with
surgery for histologically proved gastric adenocarcinoma is
based upon 312 patients randomized between August 1974 and
May 1980. Patients were stratified into three categories of
resectability, (1) complete, (2) proven incomplete, and (3)
nonresectable, prior to random treatment assignment to
surgery alone or surgery followed by adjuvant chemotherapy.
Drug therapy consisted of discrete 5-day courses
administered at 7-week intervals. Toxic reactions were
reported in association with 42% of the courses. Treatment
was suspended or discontinued in 6% of the courses because
of hematologic toxicity. Treated patients with curative
resections experienced a more favorable survival than did
controls, but the early advantage was lost by the end of the
second follow-up year. However, no statistically significant
improvements in survival or reductions in risks of
recurrence were observed. Similar proportions of treated and
control deaths were attributable to residual or recurrent
disease.
- Language of Publication
- English
- Unique Identifier
- 83284743
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- MeSH Heading (Major)
- Adenocarcinoma|*DT/MO/SU; Fluorouracil|*AD; Nitrosourea
Compounds|*AD; Semustine|*AD; Stomach Neoplasms|*DT/MO/SU
- MeSH Heading
- Aged; Clinical Trials; Drug Therapy, Combination;
Gastrectomy; Human; Laparotomy; Middle Age; Neoplasm
Recurrence, Local; Probability; Random Allocation
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 70 from database: MEDLINE
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- Title
- 5 FU infusion with mitomycin-C vs. 5 FU infusion with
methyl-CCNU in the treatment of advanced upper
gastrointestinal cancer: a Southwest Oncology Group Study.
- Author
- Buroker T; Kim PN; Groppe C; McCracken J; OBryan R;
Panettiere F; Costanzi J; Bottomley R; King GW; Bonnet J;
Thigpen T; Whitecar J; Haas C; Vaitkevicius VK; Hoogstraten
B; Heilbrun L
- Address
-
- Source
- Cancer, 1979 Oct, 44:4, 1215-21
- Abstract
- A randomized trial was conducted by the Southwest Oncology
Group (SWOG) in advanced carcinoma of the stomach and
pancreas. Patients were assigned to receive monthly
5-fluorouracil 96-hour continuous infusions with either
bolus mitomycin-C or oral methyl-CCNU. Mitomycin-C and
methyl-CCNU were administered every eight weeks. The 5
FU-mitomycin combination produced a 14% and 22% response
rate in disseminated stomach and pancreatic carcinoma,
respectively. The combination of infusion 5 FU and
methyl-CCNU achieved responses in 9% and 5% of stomach and
pancreatic tumors, respectively. There was no significant
difference in survival between limbs for either tumor.
Median survival in gastric carcinoma on the 5 FU-mitomycin
regimen was 25 weeks vs. 18 weeks on the 5 FU-METHYL-CCNU
arm. In pancreatic carcinoma median survival on the
mitomycin limb was 19 weeks as compared to 17 weeks on the
methyl-CCNU program. Leukopenia was greater for the first
course on the mitomycin limb. Regression analysis
demonstrated that performance status was the most important
pretreatment characteristic for predicting survival in both
tumors. Neither 5 FU infusion combination appears to
significantly alter the dismal prognosis of advanced upper
gastrointestinal neoplasms.
- Language of Publication
- English
- Unique Identifier
- 80044520
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- MeSH Heading (Major)
- Fluorouracil|*AD; Mitomycins|*AD; Nitrosourea
Compounds|*AD; Pancreatic Neoplasms|*DT; Semustine|*AD;
Stomach Neoplasms|*DT
- MeSH Heading
- Antineoplastic Agents|AE; Bone Marrow|DE; Clinical Trials;
Comparative Study; Drug Therapy, Combination; Female; Human;
Infusions, Parenteral; Male; Remission, Spontaneous;
Support, U.S. Gov't, P.H.S.; Time Factors
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 71 from database: MEDLINE
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- Title
- Solid phase synthesis of oligoribonucleotides using the
1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl (Ctmp)
group for the protection of the 2'-hydroxy functions and the
H-phosphonate approach.
- Author
- Sakatsume O; Ohtsuki M; Takaku H; Reese CB
- Address
- Department of Industrial Chemistry, Chiba Institute of
Technology, Japan.
- Source
- Nucleic Acids Res, 1989 May, 17:10, 3689-97
- Abstract
- The solid phase synthesis of oligoribonucleotides using
the H-phosphonate approach and the
1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl (Ctmp)
and dimethoxytrityl (DMTr) groups, respectively, for the
protection of the 2'- and 5'-hydroxy functions is described.
The use of a new reagent,
tris-(1,1,1,3,3,3-hexafluoro-2-propyl) phosphite for the
preparation of nucleoside H-phosphonate units is also
discussed in detail.
- Language of Publication
- English
- Unique Identifier
- 89282376
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- MeSH Heading (Major)
- Oligoribonucleotides|*CS
- MeSH Heading
- Base Sequence; Chromatography, High Pressure Liquid;
Indicators and Reagents; Nuclear Magnetic Resonance;
Phosphonic Acids; Phosphorus; Piperidines; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0305-1048
- Country of Publication
- ENGLAND
Record 72 from database: MEDLINE
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- Title
- Chemotherapy of advanced measurable colon and rectal
carcinoma with oral 5-fluorouracil, alone or in combination
with cyclophosphamide or 6-thioguanine, with intravenous
5-fluorouracil or beta-2'-deoxythioguanosine or with oral
3(4-methyl-cyclohexyl)-1(2-chlorethyl)-1-nitrosourea: a
Phase II-III study of the Eastern Cooperative Oncology Group
(EST 4273).
- Author
- Douglass HO Jr; Lavin PT; Woll J; Conroy JF; Carbone P
- Address
-
- Source
- Cancer, 1978 Dec, 42:6, 2538-45
- Abstract
- In a randomized multi-institutional trial of the Eastern
Cooperative Oncology Group, 316 patients with advanced
measurable colorectal adenocarcinoma were treated with a
weekly schedule of 5-fluorouracil given orally and
intravenously with oral-5-fluorouracil in combination with
cyclophosphamide or 6-thioguanine, or with oral Methyl CCNU
administered once every eight weeks. On failure or
progression, 133 protocol patients crossed-over to a
secondary therapy, while 116 other patients previously
treated with 5-fluorouracil off protocol were randomized to
treatment with Methyl CCNU or B-2'-deoxythioguanosine.
Response rates among patients who had received no prior
chemotherapy were 18% to oral 5-FU, 15% to intravenous 5-FU
and to MeCCNU, 12% to 5-FU and 6-thioguanine and 5% to
cyclophosphamide and 5-FU, with little activity (3% response
rate) in crossover or previously treated patients. Treatment
with 5-FU, particularly oral 5-FU was associated with the
least drug-related toxicity. Hematologic toxicity was
greatest with Methyl CCNU, but was no more frequent in
previously treated than in untreated patients. A tendency
toward cumulative bone marrow depression was noted. 5-FU was
effective only in ambulatory patients, whereas responses
among non-ambulatory patients were seen only in the group
treated with Methyl-CCNU.
- Language of Publication
- English
- Unique Identifier
- 79083888
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- MeSH Heading (Major)
- Adenocarcinoma|*DT; Antineoplastic Agents|*AD/AE; Colonic
Neoplasms|*DT; Rectal Neoplasms|*DT
- MeSH Heading
- Bone Marrow|DE; Clinical Trials; Comparative Study;
Cyclophosphamide|AD; Deoxyguanosine|AA/AD; Drug Therapy,
Combination; Female; Fluorouracil|AD; Human; Male; Neoplasm
Metastasis|DT; Semustine|AD; Support, U.S. Gov't, P.H.S.;
Thioguanine|AD; Thionucleosides|AD
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 73 from database: MEDLINE
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- Title
- 5FU infusion with mitomycin-C versus 5 FU infusion with
methyl-CCNU in the treatment of advanced colon cancer: a
Southwest Oncology Group Study.
- Author
- Buroker T; Kim PN; Groppe C; McCracken J; OBryan R;
Panettiere F; Coltman C; Bottomley R; Wilson H; Bonnet J;
Thigpen T; Vaitkevicius VK; Hoogstraten B; Heilbrun L
- Address
-
- Source
- Cancer, 1978 Sep, 42:3, 1228-33
- Abstract
- The Southwest Oncology Group (SWOG) in a randomized trial
evaluated 5FU infusions in combination with either
Mitomycin-C or Methyl-CCNU in patients with disseminated
large bowel cancer. A response rate of 18% was noted on the
5FU-Mitomycin limb as compared to 16% on the Methyl-CCNU arm
(p = .39). Median survival for all treated patients was 43
weeks on both arms. Myelosuppression was found to be more
significant on the Mitomycin-C arm. Regression analysis
demonstrated that performance status, sex, and primary site
were significant pretreatment characteristics for predicting
survival. The response rates associated with this burdensome
method of 5FU administration in combination with either
Mitomycin-C or Methyl-CCNU appear to offer little advantage
over bolus 5FU alone.
- Language of Publication
- English
- Unique Identifier
- 79022780
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- MeSH Heading (Major)
- Adenocarcinoma|*DT; Colonic Neoplasms|*DT;
Fluorouracil|*AD/AE; Mitomycins|*AD/AE; Nitrosourea
Compounds|*AD; Semustine|*AD/AE
- MeSH Heading
- Bone Marrow|DE; Clinical Trials; Comparative Study;
Female; Human; Infusions, Parenteral; Male; Prognosis;
Remission, Spontaneous; Support, U.S. Gov't, P.H.S.; Time
Factors
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 74 from database: MEDLINE
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- Title
- Metabolism of delta24-sterols by yeast mutants blocked in
removal of the C-14 methyl group.
- Author
- Pierce AM; Mueller RB; Unrau AM; Oehlschlager AC
- Address
-
- Source
- Can J Biochem, 1978 Aug, 56:8, 794-800
- Abstract
- We have investigated the metabolism of exogenously
provided delta24-sterols by whole cell cultures of a
polyene-resistant mutant (D10) of Candida albicans blocked
at removal of the C-14 methyl group. Comparison of the
relative efficiencies of transmethylation at C-24 of
selected sterol substrates revealed the following substrate
preferences of the Candida delta24-sterol methyltransferase
(EC 2.1.1.41): zymosterol greater than
4alpha-methylzymosterol greater than
14alpha-methylzymosterol. Exogenous 4,4-dimethylzymosterol
was not transmethylated by mutant D10. Incorporation of the
14C-labelled methyl group of
S-adenosyl-L-[methyl-14C]methionine into the sterols of a
D10 culture preloaded with zymosterol indicated that
zymosterol was a better (40 X) substrate than endogenous
lanosterolmfeeding zymosterol to D10 and a polyene-resistant
strain of Saccharomyces cerevisiae (Nys-P100) that was also
blocked at removal of the C-14 methyl group gave 24-methyl
sterols possessing delta22 and ring B unsaturation. Mutant
D10 was able to produce ergosterol from zymosterol whereas
Nys-P100 produced ergosta-7,22-dienol. When grown in the
presence of 3 micrometer 25-aza-24,25-dihydrozymosterol, a
known inhibitor of the delta24-sterol methyltransferase,
Nys-P100 accumulated 14alpha-methylzymosterol, a minor
metabolite in this mutant under normal growth conditions and
hitherto unidentified as a yeast sterol.
- Language of Publication
- English
- Unique Identifier
- 79001317
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- MeSH Heading (Major)
- Candida albicans|*ME; Lanosterol|*ME;
Methyltransferases|*ME; Saccharomyces cerevisiae|EN/*ME;
Sterols|*ME
- MeSH Heading
- Chemistry; Mutation
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-4018
- Country of Publication
- CANADA
Record 75 from database: MEDLINE
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- Title
- Effect of dietary methyl group deficiency on one-carbon
metabolism in rats.
- Author
- Cook RJ; Horne DW; Wagner C
- Address
- Department of Biochemistry, Vanderbilt University School
of Medicine, Nashville, TN 37212.
- Source
- J Nutr, 1989 Apr, 119:4, 612-7
- Abstract
- Amino acid-defined diets deficient in methyl groups have
been shown to result in a very high incidence of
hepatocellular carcinoma. It has been suggested that this is
a result of decreased levels of S-adenosylmethionine and the
undermethylation of DNA. Accordingly, the enzyme glycine
N-methyltransferase (GNMT, EC 2.1.1.20) may play a major
role in maintaining the levels of S-adenosylmethionine in
liver in response to changes in dietary methionine. The
effect of methyl-deficient, amino acid-defined diets on GNMT
activity and S-adenosylmethionine levels in rat liver was
therefore investigated. When rats were fed a defined amino
acid diet containing no choline in which homocysteine was
substituted for the methionine of the control diet at an
equimolar level, there was a rapid and marked decrease in
growth rate in spite of the fact that the rats consumed 85%
of the food eaten by control rats fed a nutritionally
adequate, defined amino acid diet. The GNMT activity in
livers of methyl-deficient rats decreased rapidly, but there
was no difference in amount of GNMT protein as measured
immunologically. In methyl-deficient rats, the levels of
S-adenosylmethionine were maintained but the levels of
S-adenosylhomocysteine were rapidly elevated compared to
control values. These changes are consistent with the
postulated role of GNMT in regulating methyl group
metabolism.
- Language of Publication
- English
- Unique Identifier
- 89199128
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- MeSH Heading (Major)
- Carbon|*ME; Choline Deficiency|*ME; Diet|*; Liver|*ME/PA;
Methionine|*DF; Methyltransferases|*ME;
S-Adenosylmethionine|*ME
- MeSH Heading
- Amino Acids|AD; Animal; Male; Methylation; Organ Weight;
Rats; Rats, Inbred F344; S-Adenosylhomocysteine|ME; Support,
Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.; Support,
U.S. Gov't, P.H.S.; Weight Gain
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3166
- Country of Publication
- UNITED STATES
Record 76 from database: MEDLINE
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- Title
- Yeast mutants blocked in removing the methyl group of
lanosterol at C-14. Separation of sterols by high-pressure
liquid chromatography.
- Author
- Trocha PJ; Jasne SJ; Sprinson DB
- Address
-
- Source
- Biochemistry, 1977 Oct, 16:21, 4721-6
- Abstract
- Sterols of a nystatin resistant mutant of the wild type
parent of Saccharomyces cerevisiae were separated by a newly
developed procedure involving high-pressure liquid
chromatography and were identified. The mutant contained
larger amounts of squalene and lanosterol (I) than the wild
type, as well as 4,14-dimethylcholesta-8,24-dien-3beta-ol
(II), 4,14-dimethylergosta-8,24(28)-dien-3beta-ol (III), and
14-methylergosta-8,24(28)-dien-3beta-ol (IV), which were not
hitherto found in yeast. These results indicated a block in
removal of the methyl group at C-14 of lanosterol. An
ergosterol requiring derivative of the mutant which carried
in addition a mutation in heme biosynthesis had the same
sterols as the parent, but at one-third the concentration.
The low level of sterols may be due to a requirement for a
heme or cytochrome in oxygenation reactions between
lanosterol and ergosterol.
- Language of Publication
- English
- Unique Identifier
- 78020850
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- MeSH Heading (Major)
- Lanosterol|IP/*ME; Saccharomyces cerevisiae|*ME;
Sterols|*/IP/ME
- MeSH Heading
- Chromatography, High Pressure Liquid; Mutation; Nuclear
Magnetic Resonance; Species Specificity; Spectrum Analysis,
Mass; Support, U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't,
P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 77 from database: MEDLINE
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- Title
- Vitamin B6 antagonists obtained by replacing or modifying
the 2-methyl group.
- Author
- Korytnyk W; Angelino N
- Address
-
- Source
- J Med Chem, 1977 Jun, 20:6, 745-9
- Abstract
- The 2-methyl group of pyridoxol was replaced with various
other groups, including 2-amino and 2-methylamino as
examples of electron-donating substituents and including
2-carboxyl, 2-carboxamide, and 2-halo as examples of
electron-withdrawing substituents. The key intermediate in
the synthesis was
3-O-benzyl-alpha4,alpha5-O-isopropylidene-alpha2-pyridoxol
(15) or the corresponding 2-aldehyde (2). Another approach
for modifying the 2 position, but chemically less
successful, started with 3-O-methylpyridoxol, which was
oxidized to the tricarboxylic acid, decarboxylated,
esterfied, and reduced with LiAlH4, providing derivatives in
which the 2-CH3 group was replaced with H. The analogues
were tested for their growth-inhibitory activity against
mouse mammary adenocarcinoma cells in culture. The 2-azine,
2-chloro, and 2-amino analogues were active as inhibitors at
ID50 approximately or equal to 10(-5) M, whereas the
2-fluoro and 2-carboxylic acid analogues were inactive at 1
X 10(-4) M. The results are contrasted with those found
earlier for similar modifications in other positions of the
vitamin B6 molecule. Although the 2-chloro analogue was
found to inhibit pyridoxal phosphokinase (KI=24 micron), the
6-chloro analogue was inactive as an inhibitor at 1 mM.
- Language of Publication
- English
- Unique Identifier
- 77209849
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- MeSH Heading (Major)
- Pyridoxine|*AA/*AI/CS
- MeSH Heading
- Adenocarcinoma|ME; Animal; Cells, Cultured; Depression,
Chemical; Mammary Neoplasms, Experimental|ME; Mice;
Structure-Activity Relationship; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2623
- Country of Publication
- UNITED STATES
Record 78 from database: MEDLINE
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- Title
- Methyl group metabolism in the pancreas of
folate-deficient rats.
- Author
- Balaghi M; Wagner C
- Address
- Department of Biochemistry, Vanderbilt University School
of Medicine, Nashville, TN.
- Source
- J Nutr, 1992 Jul, 122:7, 1391-6
- Abstract
- Several studies have suggested that the metabolism of
one-carbon compounds may have a special role in the function
of the exocrine pancreas. An amino acid-defined diet was
used to produce folate deficiency in a group of male rats.
These rats were compared with a group of rats pair-fed the
same diet supplemented with adequate folate and with a third
group fed the folate-supplemented diet with ad libitum
access. Pancreatic folate concentrations were already
severely depleted after 4 wk of feeding the deficient diet
(0.95 +/- 0.10, 5.81 +/- 0.29 and 4.58 +/- 0.30 nmol/g for
the deficient, pair-fed control and ad libitum-fed control
groups, respectively). The level of folate present in the
pancreas of nondeficient animals was second only to that
reported for liver. Urinary amylase excretion by animals in
the deficient group was higher than that by the other groups
(245.5 +/- 21.9, compared with 181.9 +/- 14.5 and 195.3 +/-
10.9 units/mg creatinine for the deficient, pair-fed control
and ad libitum-fed control groups, respectively) after 4 wk.
The ratio of S-adenosylmethionine to S-adenosylhomocysteine
was 18.6 +/- 1.6 and 14.5 +/- 1.0 after 4 wk for the ad
libitum-fed control and pair-fed control groups,
respectively, but was significantly lower at 6.3 +/- 1.1 for
the deficient group. These results indicate a profound
effect of folate deficiency upon methyl group metabolism of
the pancreas and suggest that this may result in decreased
pancreatic function.
- Language of Publication
- English
- Unique Identifier
- 92318006
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- MeSH Heading (Major)
- Folic Acid Deficiency|*ME; Pancreas|*ME;
S-Adenosylhomocysteine|*ME; S-Adenosylmethionine|*ME
- MeSH Heading
- Animal; Body Weight; Diet; Folic Acid|AD/AN; Male; Organ
Weight; Rats; Rats, Inbred Strains; Support, U.S. Gov't,
Non-P.H.S.; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3166
- Country of Publication
- UNITED STATES
Record 79 from database: MEDLINE
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- Title
- Synthesis of
N-acetyl-muramyl-L-alanyl-D-glutamic-alpha-amide(MDP) or
-alpha-methyl ester derivatives, bearing a lipophilic group
at the C-terminal peptide end.
- Author
- Lefrancier P; Petitou M; Level M; Derrien M; Choay J;
Lederer E
- Address
-
- Source
- Int J Pept Protein Res, 1979, 14:5, 437-44
- Abstract
- We report the synthesis of nine lipophilic derivatives of
N-acetyl-muramyl-L-alanyl-D-glutamic-alpha-amide (MDP) or
-alpha-methyl ester in which the gamma-carboxyl function of
the D-glutamyl residue is either esterified by a medium
chain alcohol or substituted by an L-alanyl residue
esterified by a medium or long chain alcohol. A new method
is described which easily allows one to obtain derivatives
of MDP, bearing a free or substituted amino-acyl or peptidyl
residue on the gamma-carboxyl function.
- Language of Publication
- English
- Unique Identifier
- 80136481
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- MeSH Heading (Major)
- Acetylmuramyl-Alanyl-Isoglutamine|AA/*CS;
Glycopeptides|*CS
- MeSH Heading
- Chemistry; Esters; Methods
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0300-9769
- Country of Publication
- DENMARK
Record 80 from database: MEDLINE
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- Title
- Conformation of the N(CH3)2 group in cytosine and in
simple model pyrimidines and pyridines. Steric effects of
ortho-methyl substitution on infrared spectra and molecular
dipole moments.
- Author
- Litonska E; Proba Z; Ku…akowska I; Wierzchowski KL
- Address
-
- Source
- Acta Biochim Pol, 1979, 26:1-2, 39-54
- Abstract
- Infrared spectra of amino and dimethylamino derivatives
with and without an ortho-methyl group of 4- and
5-substituted pyrimidines, 4-substituted pyridine, benzene
and of the respective cytosines were recorded in the region
of skeletal ring vibrations. Integrated intensities of ring
vibration(s) v8 at about 1600 cm-1 sensitive to the presence
of electron-donating substituents were used for elucidation
of the steric effects of ortho-methyl on the mesomeric
interaction between the -N(CH3)2 group and the ring.
Molecular dipole moments were also determined experimentally
in benzene for simple pyrimidine and pyridine derivatives
and analysed vectorially with the use of component group
moments in terms of the N(CH3)2 group conformation. The data
point to a progressive twist of the dimethylamino group in
hindered derivatives in the order: pyrimidine-5 greater than
pyridine-4 greater than pyrimidine-4. They are also in
agreement with the essential planarity of sterically crowded
m41,4,4,5cytosine.
- Language of Publication
- English
- Unique Identifier
- 80061584
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- MeSH Heading (Major)
- Aminopyridines|*AN; Bone and Bones|*AN; Cytosine|*AN;
Dimethylamines|*AN; Pyrimidines|*AN
- MeSH Heading
- Benzene|AN; Molecular Conformation; Spectrophotometry,
Infrared
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0001-527X
- Country of Publication
- POLAND
Record 81 from database: MEDLINE
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- Title
- The 4 beta-methyl group of substrate does not affect the
activity of lanosterol 14 alpha-demethylase (P-450(14)DM) of
yeast: difference between the substrate recognition by yeast
and plant sterol 14 alpha-demethylases.
- Author
- Aoyama Y; Yoshida Y
- Address
- Faculty of Pharmaceutical Sciences, Mukogawa Women's
University, Nishinomiya, Japan.
- Source
- Biochem Biophys Res Commun, 1992 Mar, 183:3, 1266-72
- Abstract
- Interaction of obtusifoliol and 24,28-dihydroobtusifoliol
with yeast lanosterol 14 alpha-demethylase (P-450(14)DM) was
studied to elucidate the role of the 4 beta-methyl group of
substrate. P-450(14)DM of Saccharomyces cerevisiae catalyzed
14 alpha-demethylation of obtusifoliol. Apparent Vmax of
obtusifoliol demethylation (15.4 nmol/min/nmol P-450) was
similar to that of 24-methylene-24,25-dihydrolanosterol
demethylation and was a little higher than those of
lanosterol and 24,25-dihydrolanosterol demethylations.
Apparent Km for obtusifoliol (12.0 microM) was higher than
those for lanosterol and
24-methylene-24,25-dihydrolanosterol but was lower than that
for 24,25-dihydrolanosterol. 24,28-Dihydroobtusifoliol was a
very poor substrate for yeast P-450(14)DM. These facts
suggest that the 4 beta-methyl group of sterol slightly
affects the activity of yeast P-450(14)DM, while
hydrogenation of a double bond in the sterol side-chain
considerably impairs the activity. This finding is a
contrast to the fact that the plant P-450(14)DM could not
catalyze demethylation of sterols having 4 beta-methyl
group, but favorably interacts with sterols having saturated
side chain.
- Language of Publication
- English
- Unique Identifier
- 92231893
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- MeSH Heading (Major)
- Cytochrome P-450|*ME; Oxidoreductases|*ME; Saccharomyces
cerevisiae|*EN
- MeSH Heading
- Cholestadienols|ME; Ergosterol|AA/ME; Plants|EN; Substrate
Specificity; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-291X
- Country of Publication
- UNITED STATES
Record 82 from database: MEDLINE
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- Title
- Properties of flavins where the 8-methyl group is replaced
by mercapto- residues.
- Author
- Moore EG; Ghisla S; Massey V
- Address
-
- Source
- J Biol Chem, 1979 Sep, 254:17, 8173-8
- Abstract
- Sulfur functions in position 8 of the flavin nucleus give
rise to new modified flavin derivatives, which should prove
useful as probes of the flavin binding domains of
flavoproteins. Here, we report on some properties of
8-nor-8-alkylmercaptoflavins and 8-nor-8-mercaptoflavin
which are readily formed by nucleophilic displacement by
alkylmercaptides or sulfide, with 8-nor-8-chloroflavins as
starting material. The new flavins are characterized by
extensive shifts in spectral properties, with very high
extinction coefficients. 8-nor-8-mercaptoriboflavin is
easily and reversibly converted to its (-S-S-) dimer.
Oxidation of the sulfur group by peracids forms first
sulfoxides and then sulfones, in which the characteristic
usual flavin spectrum is regained. A comparison of
8-SR-8-nor-flavins with 8-OR-8-nor-flavins (Ghisla, S., and
Mayhew, S.G. (1976) Eur. J. Biochem 63, 373-390) indicates
that in both classes of compounds, optical properties,
ionization constants, and oxidation-reduction potentials
follow similar patterns.
- Language of Publication
- English
- Unique Identifier
- 79239419
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- MeSH Heading (Major)
- Riboflavin|*AA; Sulfhydryl Compounds|*
- MeSH Heading
- Disulfides; Oxidation-Reduction; Spectrophotometry;
Structure-Activity Relationship; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 83 from database: MEDLINE
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- Title
- Uracil interference, a rapid and general method for
defining protein-DNA interactions involving the 5-methyl
group of thymines: the GCN4-DNA complex.
- Author
- Pu WT; Struhl K
- Address
- Department of Biological Chemistry and Molecular
Pharmacology, Harvard Medical School, Boston, MA 02115.
- Source
- Nucleic Acids Res, 1992 Feb, 20:4, 771-5
- Abstract
- We describe a novel uracil interference method for
examining protein contacts with the 5-methyl group of
thymines. The protein of interest is incubated with target
DNA containing randomly distributed deoxyuracil
substitutions that is generated by carrying out the
polymerase chain reaction in the presence of a mixture of
TTP and dUTP. After separating DNA-protein complexes away
from unbound DNA, the locations of deoxyuracil residues that
either do or do not interfere with DNA-binding are
determined by cleavage with uracil-N-glycosylase followed by
piperidine. Using this uracil interference assay, we show
that the methyl groups of the four core thymines, but not
the two peripheral thymines, of the optimal binding site
(ATG-ACTCAT) are important for high affinity binding of
GCN4. Similar, but not identical, results are obtained using
KMnO4 interference, another method used for studying
protein-DNA interactions involving thymine residues. These
observations strongly suggest that GCN4 directly contacts
the 5-methyl groups of the four core thymines that lie in
the major groove of the target DNA. Besides providing
specific structural information about protein-DNA complexes,
uracil interference should also be useful for identifying
DNA-binding proteins and their target sites in eukaryotic
promoter regions.
- Language of Publication
- English
- Unique Identifier
- 92178971
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- MeSH Heading (Major)
- DNA-Binding Proteins|*ME; Fungal Proteins|*ME;
Oligodeoxyribonucleotides|*ME; Thymine|*ME; Transcription
Factors|*ME; Uracil|*ME
- MeSH Heading
- Base Sequence; Binding Sites|GE; Molecular Sequence Data;
Polymerase Chain Reaction; Potassium Permanganate|ME;
Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0305-1048
- Country of Publication
- ENGLAND
Record 84 from database: MEDLINE
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- Title
- Human metabolism of antipyrine labelled with 14C in the
pyrazolone ring or in the N-methyl group.
- Author
- Uchino H; Inaba T; Kalow W
- Address
-
- Source
- Xenobiotica, 1983 Mar, 13:3, 155-62
- Abstract
- After ingestion of [N-14CH3]antipyrine by two healthy male
subjects, the urinary recoveries of radioactivity plus
norantipyrine (non-radioactive) were 63 and 73%. After
ingestion of [3-14C]antipyrine in the same two subjects, the
urinary recoveries of radioactivity were 84 and 99%.
Therefore, N-demethylated metabolites which have not been
identified before, besides norantipyrine, must account for
21--26% of the dose. Serum half-lives of total 14C were
about 50% greater than those of unchanged antipyrine. The
difference was less in the saliva. Three major metabolites
of antipyrine, norantipyrine, 4-hydroxyantipyrine and
3-hydroxymethylantipyrine, in urine were determined by
radio-t.l.c. and g.l.c. These three metabolites and
antipyrine accounted for 50--69% of the administered dose.
The urinary excretion half-lives of these three metabolites
were similar to each other and to the serum half-life of
antipyrine. 3-Hydroxymethylantipyrine in one subject was
excreted more slowly than the other metabolites. The
radioactive metabolite not extracted from urine by organic
solvents was very polar, as judged by t.l.c.
- Language of Publication
- English
- Unique Identifier
- 83304129
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- MeSH Heading (Major)
- Antipyrine|*ME
- MeSH Heading
- Adult; Biotransformation; Carbon Radioisotopes|DU;
Dealkylation; Half-Life; Human; Male; Middle Age; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0049-8254
- Country of Publication
- ENGLAND
Record 85 from database: MEDLINE
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- Title
- Methyl group metabolism in sheep.
- Author
- Snoswell AM; Xue GP
- Address
- Department of Animal Sciences, University of Adelaide,
Glen Osmond, South Australia.
- Source
- Comp Biochem Physiol [B], 1987, 88:2, 383-94
- Abstract
- 1. Sheep have a very low intake of methyl nutrients in the
post-ruminant state, due to the almost complete degradation
of dietary choline by rumen microorganisms, the lack of
dietary creatine and the relatively low content of
methionine in microbial proteins. 2. Methylneogenesis
provides a major source of labile methyl groups in
post-ruminant sheep and impairment of the methylneogenesis
leads to a marked reduction of the labile methyl pool. 3.
S-Adenosylmethionine (AdoMet) metabolism via
transmethylation is most active in sheep liver and pancreas
and is regulated by the availability of methionine and
intracellular ratios of AdoMet to S-adenosylhomocysteine
(AdoHcy). 4. Adaptive mechanisms which arise as a
consequence of the poor methyl nutrition in post-ruminant
sheep are a marked reduction of labile methyl catabolism and
an increase in the capacity of methylneogenesis.
- Language of Publication
- English
- Unique Identifier
- 88110428
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- MeSH Heading (Major)
- Methylation|*; Sheep|*ME
- MeSH Heading
- Adaptation, Physiological; Animal; Animal Nutrition;
S-Adenosylmethionine|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE; REVIEW; REVIEW, ACADEMIC
- ISSN
- 0305-0491
- Country of Publication
- ENGLAND
Record 86 from database: MEDLINE
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- Title
- An EORTC Gastrointestinal Group phase III evaluation of
combinations of methyl-CCNU, 5-fluorouracil, and adriamycin
in advanced gastric cancer.
- Author
- Lacave A; Wils J; Bleiberg H; Diaz Rubio E; Duez N;
Dalesio O
- Address
-
- Source
- J Clin Oncol, 1987 Sep, 5:9, 1387-93
- Abstract
- In a prospective phase III multicenter trial, 189 patients
with advanced measurable and nonmeasurable gastric cancer
were randomized to receive 5-fluorouracil (5-FU) combined
with Adriamycin (FA) or FA plus methyl-CCNU (MeFA). The
response rate in patients with measurable disease was 10%
(three of 29), and 18% (five of 28), respectively. No
difference in the duration of survival was detected (P =
.14; log rank test). Median survivals were 21 and 32 weeks,
respectively. Toxicity was moderate, but there have been two
toxic deaths among the patients who received FA. Because of
the low response rate and the short survival, neither
regimen can be recommended for the treatment of advanced
gastric cancer.
- Language of Publication
- English
- Unique Identifier
- 87310591
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- MeSH Heading (Major)
- Antineoplastic Agents, Combined|*TU; Doxorubicin|*AD;
Fluorouracil|*AD; Nitrosourea Compounds|*AD; Semustine|*AD;
Stomach Neoplasms|*DT
- MeSH Heading
- Adenocarcinoma|DT; Adult; Aged; Clinical Trials;
Comparative Study; Female; Human; Male; Middle Age;
Prospective Studies; Random Allocation; Support, U.S. Gov't,
P.H.S.
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE; RANDOMIZED CONTROLLED
TRIAL
- ISSN
- 0732-183X
- Country of Publication
- UNITED STATES
Record 87 from database: MEDLINE
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- Title
- Isotope effects on the metabolism and pulmonary toxicity
of butylated hydroxytoluene in mice by deuteration of the
4-methyl group.
- Author
- Mizutani T; Yamamoto K; Tajima K
- Address
-
- Source
- Toxicol Appl Pharmacol, 1983 Jun, 69:2, 283-90
- Abstract
- A comparative test in mice for pulmonary toxicity between
butylated hydroxytoluene (2,6-di-tert.-butyl-4-methylphenol,
BHT) and 2,6-di-tert.-butyl-4-[alpha, alpha,
alpha-2H3]methylphenol (BHT-d3) showed a significantly lower
toxic potency of the latter. The rate of in vitro BHT
metabolism to
2,6-di-tert.-butyl-4-methylene-2,5-cyclohexadienone (BHT-QM)
was slowed by deuterating BHT in the 4-methyl group. On the
other hand, the rate of in vitro metabolism to
2,6-di-tert.-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone
(BHT-OH) was increased with the deuteration. A similar
isotope effect of the deuterium substitution on the in vivo
metabolic rates of BHT was observed. These observations
support the concept that the lung damage caused by BHT is
mediated by BHT-QM. The pulmonary toxicity of
2-tert.-butyl-4-ethylphenol (4-EP) and their deuterated
analogs was also compared.
2-tert.-Butyl-4-[1,1-2H2]ethylphenol (4-EP-d2) showed a
significantly lower toxic potency than 4-EP, whereas
2-tert.-butyl-4-[2,2,2-2H3]ethylphenol (4-EP-d3) showed a
toxic potency comparable to that of 4-EP. This result is
consistent with the hypothesis that a quinone methide
metabolite is responsible for the onset of lung damage
produced by 4-EP as well as BHT.
- Language of Publication
- English
- Unique Identifier
- 83250019
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- MeSH Heading (Major)
- Butylated Hydroxytoluene|AA/*ME/TO; Lung Diseases|*CI
- MeSH Heading
- Animal; Biotransformation; Cyclohexanones|ME; Deuterium;
In Vitro; Liver|ME; Male; Mice
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0041-008X
- Country of Publication
- UNITED STATES
Record 88 from database: MEDLINE
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- Title
- Altered metabolism of the methionine methyl group in the
leukocytes of patients with schizophrenia.
- Author
- Ismail L; Sargent T 3d; Dobson EL; Pollycove M
- Address
-
- Source
- Biol Psychiatry, 1978 Dec, 13:6, 649-60
- Abstract
- Previous work has indicated that abnormal methylation
processes may be associated with schizophrenia. In this
study, leukocytes from patients with schizophrenia were
incubated with methyl-14C-L-methionine and the evolved 14CO2
measured. With increasing concentration of methionine, the
evolved 14CO2 was lower in the patients than in normal
control subjects. The incorporation of 14C into protein was
the same in both groups, and when carboxyl-14C-L-methionine
was used the evolved 14CO2 was the same in both groups, thus
excluding the possibility that altered incorporation into
protein or oxidation of the methionine molecule as a whole
were responsible. The observed differences in
methionine-methyl metabolism suggest that an abnormality in
transmethylation processes or in oxidation of the methyl
group to CO2 is associated with schizophrenia. That this
occurs in a peripheral tissue indicates that the abnormality
is not restricted to the central nervous system.
- Language of Publication
- English
- Unique Identifier
- 79104097
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- MeSH Heading (Major)
- Leukocytes|*ME; Methionine|*BL; Schizophrenia|*BL
- MeSH Heading
- Adult; Carbon Dioxide|BL; Female; Human; Male;
Methylation; Middle Age; Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3223
- Country of Publication
- UNITED STATES
Record 89 from database: MEDLINE
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- Title
- Methyl beta-glycosides of
N-acetyl-6-O-(omega-aminoacyl)muramyl-L-alanyl-D-isoglutamines,
and their conjugates with meningococcal group C
polysaccharide.
- Author
- Ponpipom MM; Rupprecht KM
- Address
-
- Source
- Carbohydr Res, 1983 Feb, 113:1, 45-56
- Abstract
- Spacer arms 2.1-3.7 nm (21-37 A) long were prepared, and
coupled with the methyl beta-glycoside of
N-acetylmuramyl-L-alanyl-D-isoglutamine benzyl ester, to
give blocked 6-acylates. Deprotection was effected with
palladium chloride and triethyl-silane. Chemical conjugates
of MDP-meningococcal group C polysaccharide were then
synthesized, in attempts to enhance the immunogenicity of
the polysaccharide antigen.
- Language of Publication
- English
- Unique Identifier
- 83180292
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- MeSH Heading (Major)
- Acetylmuramyl-Alanyl-Isoglutamine|*AA;
Methylglycosides|*CS; Polysaccharides, Bacterial|*IM
- MeSH Heading
- Indicators and Reagents; Structure-Activity Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-6215
- Country of Publication
- NETHERLANDS
Record 90 from database: MEDLINE
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- Title
- Significance of the methyl group on the oxazine ring of
ofloxacin derivatives in the inhibition of bacterial and
mammalian type II topoisomerases.
- Author
- Hoshino K; Sato K; Akahane K; Yoshida A; Hayakawa I; Sato
M; Une T; Osada Y
- Address
- Research Institute, Daiichi Pharmaceutical Co., Ltd.,
Tokyo, Japan.
- Source
- Antimicrob Agents Chemother, 1991 Feb, 35:2, 309-12
- Abstract
- A study was made of the correlation between the in vitro
inhibitory effects of several quinolones, including four
ofloxacin derivatives, on bacterial DNA gyrase from
Escherichia coli KL-16 and on topoisomerase II from fetal
calf thymus. No correlation was observed between the
inhibitions of DNA gyrase activity and topoisomerase II
activity. On the other hand, the inhibitory effects of these
quinolones against topoisomerase II were closely correlated
with their inhibition of cell growth. Furthermore, among the
oxazine derivatives tested, the derivative with a methyl
group at position 3 in an S configuration showed the highest
activity against DNA gyrase and derivatives without a methyl
group on the oxazine ring were more potent against
topoisomerase II than those with a methyl group. Among these
derivatives, DR-3355, the S isomer of ofloxacin, showed the
highest activity against DNA gyrase and low activity against
topoisomerase II. These results indicate that the methyl
group on the oxazine ring plays an important role in the
inhibitory activities of ofloxacin derivatives for these
enzymes.
- Language of Publication
- English
- Unique Identifier
- 91221603
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- MeSH Heading (Major)
- DNA Topoisomerase (ATP-Hydrolysing)|*AI; Ofloxacin|AA/*PD
- MeSH Heading
- Animal; Bacteria|IM; Cattle; Cell Division; Colony-Forming
Units Assay; DNA, Bacterial|AN; Escherichia coli|EN; Mice;
Microbial Sensitivity Tests; Molecular Conformation; Stem
Cells|DE; Structure-Activity Relationship; Thymus Gland|EN
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0066-4804
- Country of Publication
- UNITED STATES
Record 91 from database: MEDLINE
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- Title
- Developmental changes in the activities of enzymes related
to methyl group metabolism in sheep tissues.
- Author
- Xue GP; Snoswell AM
- Address
-
- Source
- Comp Biochem Physiol [B], 1986, 83:1, 115-20
- Abstract
- The activities of choline oxidase and betaine-homocysteine
methyltransferase increased markedly in pre-ruminant lamb
liver after birth and subsequently decreased when the lambs
reached the ruminant state, while the developmental changes
in hepatic 5-methyl-H4folate-homocysteine methyltransferase
were negatively correlated with those of
betaine-homocysteine methyltransferase. Hepatic phospholipid
methyltransferase was elevated almost four-fold by the 10th
postnatal day, but declined thereafter. Hepatic glycine
methyltransferase in one-day-old lambs increased 55-fold,
compared with that of fetuses, and thereafter decreased
dramatically with age. Guanidoacetate methyltransferase,
glycine methyltransferase and betaine-homocysteine
methyltransferase in sheep pancreas increased markedly with
age and were many times higher than the hepatic enzymes in
adult sheep. Choline oxidase, betaine-homocysteine
methyltransferase, cystathionine beta-synthase and glycine
methyltransferase in adult sheep liver were much lower than
those in rat. These results illustrate the conservative
features of methyl group metabolism in postruminant sheep.
- Language of Publication
- English
- Unique Identifier
- 86107232
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- MeSH Heading (Major)
- Liver|EN/*GD; Methyltransferases|*ME; Sheep|*GD
- MeSH Heading
- Aging; Alcohol Oxidoreductases|ME; Animal; Kinetics;
Methylation; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0305-0491
- Country of Publication
- ENGLAND
Record 92 from database: MEDLINE
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- Title
- Observation of the terminal methyl group in fatty acids of
the linolenic series by a new 1H NMR pulse sequence
providing spectral editing and solvent suppression.
Application to excised frog muscle and rat brain.
- Author
- Arús C; Westler WM; Bárány M; Markley JL
- Address
-
- Source
- Biochemistry, 1986 Jun, 25:11, 3346-51
- Abstract
- A new 1H NMR pulse sequence is described that combines
water suppression with the selective observation of signals
from coupled spin systems. The pulse sequence is easy to set
up and compensates for pulse width inhomogeneity in the
biological sample. Suppression of the water signal is
achieved by pulses that return the water spins to their
equilibrium position; spectral editing is based on the J
modulation present in spin-echo spectra and its inhibition
by coherent decoupling at one of the resonances of the spin
system of interest. The pulse sequence, which was designed
for 1H NMR spectroscopy of tissue, was tested at 470 MHz on
excised frog muscle and rat brain. The lactate methyl
resonance of caffeine-treated frog sartorius muscle was
observed selectively by irradiation at the position of its
alcoholic proton. The terminal methyl signal of linolenic
acid, along with other fatty acids of the linolenic series
(first double bond in the omega-3 position), was observed
selectively by irradiation at the position of its omega-1
methylene group. 1H NMR spectra of rat brain were edited to
reveal the terminal methyl of either linolenic series or all
other fatty acids. The results suggest that the terminal
methyl groups of fatty acids of the linolenic series (mostly
docosahexaenoic acid, 22:6) have higher mobility than those
of all other fatty acids.
- Language of Publication
- English
- Unique Identifier
- 86269918
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- MeSH Heading (Major)
- Brain Chemistry|*; Linolenic Acids|*AN; Muscles|*AN
- MeSH Heading
- Animal; Nuclear Magnetic Resonance|MT; Rana pipiens; Rats;
Structure-Activity Relationship; Support, Non-U.S. Gov't;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 93 from database: MEDLINE
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- Title
- Destabilization of the duplex and the high-salt Z-form of
poly(dG-methyl5dC) by substitution of ethyl for the 5-methyl
group.
- Author
- Sági J; Szemzö A; Otvös L; Vorlícková M; Kypr J
- Address
- Central Research Institute for Chemistry, Hungarian
Academy of Sciences, Budapest.
- Source
- Int J Biol Macromol, 1991 Dec, 13:6, 329-36
- Abstract
- The B-to-Z conformational transition of poly(dG-dC) is
highly promoted by 5-methyl substitution of the dC moiety,
i.e. in poly(dG-methyl5dC). By the synthesis of a new
poly(dG-dC) analogue, poly(dG-ethyl5dC), the effect of a
longer alkyl-chain substituent of dC on structure and
conformation has been studied with ultraviolet absorption
melting profiles and circular dichroism spectroscopy. The
5-ethyl substituent in poly(dG-ethyl5dC) destabilizes the
duplex structure against thermal denaturation compared with
both poly(dG-methyl5dC) and poly(dG-dC). C.d. studies also
reveal that for the high-salt B-Z transition of
poly(dG-ethyl5dC) a higher NaCl concentration is required
than for that of poly(dG-methyl5dC), although much lower
than for poly(dG-dC). However low-salt Z-DNA in
poly(dG-ethyl5dC) shows unique features, e.g. it needs no
divalent cations to be stable. The low-salt B-Z transition
of poly(dG-ethyl5dC) can also be observed by the
absorption-temperature melting profile, in contrast to both
poly(dG-methyl5dC) and poly(dG-dC). The effects of MgCl2
concentration, temperature, acid pH and trifluorethanol on
the conformation of poly(dG-ethyl5dC) have also been
determined.
- Language of Publication
- English
- Unique Identifier
- 92126596
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- MeSH Heading (Major)
- Deoxyribonucleosides|*CH; DNA|*CH
- MeSH Heading
- Circular Dichroism; Hydrogen-Ion Concentration; Nucleic
Acid Conformation; Polydeoxyribonucleotides|CH; Sodium
Chloride|CH; Support, Non-U.S. Gov't; Temperature;
Trifluoroethanol|CH
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0141-8130
- Country of Publication
- ENGLAND
Record 94 from database: MEDLINE
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- Title
- Base stacking and molecular polarizability: effect of a
methyl group in the 5-position of pyrimidines.
- Author
- Sowers LC; Shaw BR; Sedwick WD
- Address
- Department of Medicine, Duke University, Durham, N.C.
- Source
- Biochem Biophys Res Commun, 1987 Oct, 148:2, 790-4
- Abstract
- Substitution of a methyl group in the 5-position of
pyrimidines increases melting temperatures and modifies
biological properties of DNA. Increased DNA stability is
often attributed to hydrophobic interactions between water
and the methyl group. However, we present evidence that the
major effect of methyl substitution is to increase the
molecular polarizability of the pyrimidine, thereby
increasing the base stacking. Experimentally determined base
stacking interaction constants for free bases in water are
shown to correlate well with calculated molecular
polarizability and DNA melting temperatures.
- Language of Publication
- English
- Unique Identifier
- 88076957
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- MeSH Heading (Major)
- Adenine|*; DNA|*; Nucleic Acid Conformation|*;
Pyrimidines|*
- MeSH Heading
- Methylation; Solubility; Spectrophotometry, Ultraviolet;
Structure-Activity Relationship
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-291X
- Country of Publication
- UNITED STATES
Record 95 from database: MEDLINE
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- Title
- Repair of alkylated DNA in Escherichia coli. Methyl group
transfer from O6-methylguanine to a protein cysteine
residue.
- Author
- Olsson M; Lindahl T
- Address
-
- Source
- J Biol Chem, 1980 Nov, 255:22, 10569-71
- Abstract
- O6-Methylguanine residues disappear from alkylated DNA by
an inducible repair process in Escherichia coli. The
reaction can be studied in a cell-free system, using DNA
treated with a radioactive methylating agent as substrate.
The disappearance of labeled O6-methylguanine from DNA is
not accompanied by release of radioactive material in an
acid-soluble form. Instead, the methyl group of
O6-methylguanine appears to be transferred enzymatically to
a protein cysteine residue. Radioactively labeled
S-methylcysteine has been identified in protein hydrolysates
after incubation of the alkylated DNA with a partly purified
E. coli methyltransferase activity. The radioactive amino
acid residue shows properties identical with those of
S-methylcysteine by automatic amino acid analysis and paper
chromatography in several solvent systems. Moreover,
oxidation of the compound with hydrogen peroxide yields a
product which co-chromatographs with S-methylcysteine
sulfone.
- Language of Publication
- English
- Unique Identifier
- 81046903
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- MeSH Heading (Major)
- DNA Repair|*; DNA, Bacterial|*ME; Escherichia coli|*ME
- MeSH Heading
- Alkylation; Bacterial Proteins|ME; Cysteine|AA/AN/ME;
Guanine|AA; Methylation; Methyltransferases|ME; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 96 from database: MEDLINE
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- Title
- Thiol-group reactivity, hydrophilicity and stability of
alloxan, its reduction products and its N-methyl derivatives
and a comparison with ninhydrin.
- Author
- Lenzen S; Munday R
- Address
- Institute of Pharmacology and Toxicology, University of GÂottingen,
Germany.
- Source
- Biochem Pharmacol, 1991 Sep, 42:7, 1385-91
- Abstract
- The diabetogenic agent, alloxan, is a hydrophilic and
chemically unstable compound. The logarithm of the
octanol/water partition coefficient of alloxan was found to
be -1.86; its half-life at pH 7.4 and 37 degrees in
phosphate buffer was 1.5 min. The partition coefficients and
half-lives of the alloxan reduction products, alloxantin and
dialuric acid, were very similar to those of the parent
compound; N-methylalloxan and N,N'-dimethylalloxan were less
hydrophilic but more unstable. Ninhydrin was found also to
be hydrophilic although this compound, in contrast to
alloxan and its derivatives, was quite stable in aqueous
solution. Alloxan and its N-methyl derivatives were reduced
by thiols and in the presence of glutathione and cysteine,
rapid redox cycling occurred, with formation of 'active
oxygen' species; no such reaction was observed, however,
with ninhydrin. Comparatively slow redox cycling was
recorded with alloxan derivatives and dithiothreitol
although rapid cycling occurred with ninhydrin and this
dithiol. Such differences may explain why ninhydrin does not
share with alloxan a selective toxic effect upon the
pancreatic B-cell.
- Language of Publication
- English
- Unique Identifier
- 92029020
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- MeSH Heading (Major)
- Alloxan|AA/*CH; Ninhydrin|*CH; Sulfhydryl Compounds|*CH
- MeSH Heading
- Barbiturates|CH; Buffers; Comparative Study;
Oxidation-Reduction; Solubility; Spectrophotometry; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2952
- Country of Publication
- ENGLAND
Record 97 from database: MEDLINE
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- Title
- 5-Fluorouracil, methyl-CCNU, and radiotherapy with or
without testolactone for localized adenocarcinoma of the
exocrine pancreas: a Southwest Oncology Group Study.
- Author
- McCracken JD; Ray P; Heilbrun LK; Vaitkevicius VK; Saiki
JH; Rivkin SE; Rossof AH; Moore TN
- Address
-
- Source
- Cancer, 1980 Oct, 46:7, 1518-22
- Abstract
- Since August 1975, 69 patients with localized pancreatic
carcinoma (extent of tumor confined to a 15 cm x 15 cm
radiotherapy port) have received either Regimen A,
comprising radiotherapy (6,000 rad) to the tumor area with
simultaneous combination chemotherapy utilizing methyl-CCNU,
125 mg/m2 orally, every six weeks, and 5-fluorouracil, 400
mg/m2 intravenously, weekly; or Regimen B, comprising
Regimen A with the addition of testolactone, 200 mg, orally
every day. Thirty-eight patients on Regimen A and 30
patients on Regimen B are currently evaluable. Median
survival, which appeared not to be affected by the addition
of testolactone, was 38 weeks for those on Regimen A and 30
weeks for those on Regimen B (P = 0.677). The median
survival time for all patients was 38 weeks. Good
performance status did correlate with improved survival vs.
poor performance status (46 weeks vs. 20 weeks, P = .008).
Fifteen patients have survived for more than 52 weeks, with
the longest survival time being 160 + weeks, and in 3 cases
all therapy has been discontinued. However, most patients
experienced moderate to severe hematologic toxic reactions.
There was one treatment-related death and significant
gastrointestinal bleeding developed in 6. Because of the
toxic reactions of this program, it should not be considered
in favor of similar less aggressive programs.
- Language of Publication
- English
- Unique Identifier
- 81022525
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- MeSH Heading (Major)
- Adenocarcinoma|*TH; Fluorouracil|*AD; Nitrosourea
Compounds|*AD; Pancreatic Neoplasms|*TH; Semustine|*AD;
Testolactone|*AD
- MeSH Heading
- Aged; Agranulocytosis|CI; Anorexia|CI; Antineoplastic
Agents|AE; Clinical Trials; Dose-Response Relationship,
Radiation; Drug Administration Schedule; Drug Therapy,
Combination; Gastrointestinal Hemorrhage|CI; Human; Middle
Age; Nausea|CI; Prognosis; Support, U.S. Gov't, P.H.S.;
Thrombocytopenia|CI; Vomiting|CI
- Publication Type
- CLINICAL TRIAL; JOURNAL ARTICLE
- ISSN
- 0008-543X
- Country of Publication
- UNITED STATES
Record 98 from database: MEDLINE
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- Title
- Structure--activity relationships in cephalosporins
prepared from penicillins. 2. Analogues of cephalexin
substituted in the 3-methyl group.
- Author
- Brain EG; Eglington AJ; James BG; Nayler JH; Osborne NF;
Pearson MJ; Smale TC; Southgate R; Tolliday P; Basker MJ;
Mizen LW; Sutherland R
- Address
-
- Source
- J Med Chem, 1977 Aug, 20:8, 1086-90
- Abstract
- A previously outlined general procedure for preparing
various 3-substituted cephalosporins from the penicillin
nucleus has been used, with modifications where required, to
prepare a series of analogues of cephalexin with various
substituents in the 3-methyl group. The 3-substituents most
conducive to broad-spectrum antibacterial activity were
3-pyridylmethyl and m- or p-carboxybenzyl. The compounds
were only poorly absorbed by the oral route in mice, but the
3-(carboxybenzyl) compounds gave more prolonged useful serum
levels than the usual cephalosporins.
- Language of Publication
- English
- Unique Identifier
- 77252232
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- MeSH Heading (Major)
- Cephalexin|*AA/BL/CS/PD
- MeSH Heading
- Animal; Bacteria|DE; Mice; Microbial Sensitivity Tests;
Staphylococcus aureus|DE; Structure-Activity Relationship;
Time Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2623
- Country of Publication
- UNITED STATES
Record 99 from database: MEDLINE
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- Title
- Methyl group analysis of virion-associated
high-molecular-weight RNA synthesized in vitro by purified
vaccinia virus.
- Author
- Nuss DL; Paoletti E
- Address
-
- Source
- J Virol, 1977 Jul, 23:1, 110-6
- Abstract
- The methylation pattern of virion-associated
high-molecular-weight RNA synthesized in vitro by purified
vaccinia virus has been determined. Analysis of purified
high-molecular-weight RNA synthesized with
S-[methyl-3H]-adenosylmethionine and alpha[32P]UTP as
precursors gave the following results. (i) Eessentially all
molecules contained blocked and methylated structures of the
type m7G(5')ppp(5')Gm and m7G(5')ppp(5')Am. (ii) There was
no detectable methylation at internal sites. (iii) Under
several different conditions of synthesis, the ratio of
molecules containing m7G(5')ppp(5')Gm to those containing
m7G(5')ppp(5')Am was imilar for both the virion-associated
high-molecular-weight RNA and the virion-released 8-12S
mRNA.
- Language of Publication
- English
- Unique Identifier
- 77230582
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- MeSH Heading (Major)
- RNA, Messenger|*BI; RNA, Viral|*BI; Vaccinia Virus|*ME
- MeSH Heading
- Base Sequence; Cell-Free System; Hela Cells; Methylation;
Molecular Weight; S-Adenosylmethionine|ME; Uracil
Nucleotides|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-538X
- Country of Publication
- UNITED STATES
Record 100 from database: MEDLINE
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- Title
- Synthesis and biochemical studies of analogs of
platelet-activating factor bearing a methyl group at C2 of
the glycerol backbone.
- Author
- Bittman R; Witzke NM; Lee TC; Blank ML; Snyder F
- Address
-
- Source
- J Lipid Res, 1987 Jun, 28:6, 733-8
- Abstract
- Two platelet-activating factor (PAF) analogs containing a
methyl group at C2 of the glycerol moiety were synthesized,
and some of their biochemical properties were investigated.
1-O-Hexadecyl-2-C,O-dimethyl-rac-glycero-3-phosphocholine
(2-methyl-2-methoxy PAF) was prepared in a synthetic scheme
beginning with the etherification of 2-methylpropen-1-ol. A
reaction sequence involving hydroxylation, tritylation,
alkylation, and detritylation afforded
1-O-hexadecyl-2-C,O-dimethyl-rac-glycerol, which was
converted into the phosphocholine. A 2-lyso derivative of
this PAF analog (2-methyl-lyso PAF) was synthesized from
1-O-hexadecyl-2-C-methyl-3-O-trityl-rac-glycerol.
Benzylation followed by detritylation gave
1-O-hexadecyl-2-C-methyl-2-O-benzyl-rac-glycerol, which was
converted into the phosphocholine compound. Hydrogenolysis
afforded 1-O-hexadecyl-2-C-methyl-rac-glycero-3-phospholine
(2-methyl-lyso PAF). The 2-methyl-lyso PAF analog served as
a substrate for the acetyl-CoA-dependent acetyltransferase
that acetylates
1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine. However,
2-methyl-lyso PAF did not have a significant effect on the
activities of a CoA-independent transacylase or of the
acetylhydrolase that inactivates PAF, and thus does not
appear to be a substrate or an inhibitor, respectively, for
these enzymes. In addition, this analog exhibited only
one-half of the antitumor activity of
rac-1-O-alkyl-2-methoxy-rac-glycero-3-phosphocholine in
human leukemic (HL-60) cells, and elicited no hypotensive
response in rats and no platelet-activating
activity.(ABSTRACT TRUNCATED AT 250 WORDS)
- Language of Publication
- English
- Unique Identifier
- 87282090
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- MeSH Heading (Major)
- Platelet Activating Factor|*AA/CS/PD; Serotonin|*SE
- MeSH Heading
- Acetylation; Acetyltransferases|ME; Animal;
Antihypertensive Agents|CS; Antineoplastic Agents|CS; Blood
Platelets|DE/SE; Comparative Study; Methylation;
Phospholipases A|BL; Rats; Rats, Inbred F344; Support, U.S.
Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-2275
- Country of Publication
- UNITED STATES
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