Neopterin und Neopterin-3′-phosphat als Vorläufer der Folsäure bei Mycobacterium smegmatis

1969 ◽  
Vol 24 (5) ◽  
pp. 569-574 ◽  
Author(s):  
L. Jaenicke ◽  
Ch. Molzberger ◽  
I. Schlie ◽  
R. Tschesche ◽  
K. Brandau ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Side Chain ◽  
Isotopic Data ◽  
Carbon Fragment ◽  
Folate Biosynthesis ◽  
Methylene Group

Extracts of Mycobacterium smegmatis synthesise dihydro-pteroate and dihydro-folate from dihydro-pteridine-6-carbinol as well as from dihydro-neopterin and dihydro-neopterin-3′-phosphate. The 7-isomers of the pteridine precursors are neither substrates nor inhibitors of folate biosynthesis. Side-chain 14C-labelled dihydro-neopterin yields similarly labelled dihydro-folate. From the isotopic data it is concluded that a two-carbon fragment is split off the chain and that C-1′ of dihydroneopterin becomes the bridging methylene group between the pteridine and the p-aminobenzoyl moiety of the compound produced.

One Methylene Group in the Side Chain Can Alter by 90 Degrees the Orientation of a Main-Chain Liquid Crystal on a Unidirectional Substrate

2018 ◽  
Vol 7 (4) ◽  
pp. 453-458
Author(s):  
Yaroslav Odarchenko ◽  
Matthieu Defaux ◽  
Martin Rosenthal ◽  
Azaliia Akhkiamova ◽  
Polina Bovsunovskaya ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Side Chain ◽  
Methylene Group

Microbial degradation of [14C]polystyrene and 1,3-diphenylbutane

1978 ◽  
Vol 24 (7) ◽  
pp. 798-803 ◽  
Author(s):  
M. Sielicki ◽  
D. D. Focht ◽  
J. P. Martin
Keyword(s):  
Microbial Degradation ◽  
Soil Microorganisms ◽  
Phenylacetic Acid ◽  
Side Chain ◽  
Microbial Oxidation ◽  
Initial Examination ◽  
Enrichment Cultures ◽  
Oxidative Reactions ◽  
Degradation Rates ◽  
Carbon Fragment

Microbial degradation of [β-14C]polystyrene and 1,3-diphenylbutane, a compound structurally representing the smallest repeating unit of styrene (dimer), was investigated in soil and liquid enrichment cultures. Degradation rates in soil, as determined by 14CO2 evolution from applied [14C]polystyrene, varied from 1.5 to 3.0% for a 4-month period. Although relatively low, these percentages were 15 to 30 times greater than values previously reported. Enrichment cultures, containing 1,3-diphenylbutane as the only carbon source, were used to determine the mechanisms of microbial oxidation of the polymer chain ends. Metabolism of 1,3-diphenylbutane appeared to involve the attack by a monooxygenase to form 2-phenyl-4-hydroxyphenylbutane followed by a further oxidation and subsequent fission of the benzene ring to yield 4-phenylvaleric acid and an unidentified 5-carbon fragment via the classic meta-fission pathway. Phenylacetic acid was probably formed from 4-phenylvaleric acid by subsequent β-oxidation of the side chain, methyl-oxidation, and decarboxylation. An initial examination of the population of microorganisms in the diphenylbutane enrichment cultures indicated that these oxidative reactions are carried out by common soil microorganisms of the genera Bacillus, Pseudomonas, Micrococcus, and Nocardia.

scholarly journals The role of conjugation reactions in enhancing biliary secretion of bile acids

1983 ◽  
Vol 214 (3) ◽  
pp. 923-927 ◽  
Author(s):  
D A Vessey ◽  
J Whitney ◽  
J L Gollan
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Hepatic Uptake ◽  
Biliary Secretion ◽  
Side Chain ◽  
Isolated Perfused Rat Liver ◽  
Rat Livers ◽  
Kinetics Of ◽  
Methylene Group

Shortening the five-carbon carboxylic acid side chain of cholic acid by one methylene group gave rise to a bile acid (norcholate) that was not a substrate for the bile acid-conjugating enzymes. The metabolism and biliary secretion of norcholate in intact liver was examined in the isolated perfused rat liver system. When rat livers were perfused with 14-20 microM solutions of norcholate for 10 min, norcholate was found in the unconjugated form in liver, venous effluent and bile. Neither tauronorcholate nor glyconorcholate was detectable by high-pressure liquid chromatography or fast-atom-bombardment mass spectrometry. The kinetics of hepatic uptake and biliary secretion of norcholate was compared with that for cholate, taurocholate and chemically synthesized tauronorcholate. The latter three bile acids were completely cleared from the perfusate and efficiently secreted into the bile. However, norcholate was incompletely extracted from the perfusate, and this was shown to be at least partially due to its relatively lower rate of hepatic uptake. Furthermore, the rate of norcholate secretion into bile was greatly reduced relative to the secretion of cholate or chemically synthesized tauronorcholate, even though the concentration of norcholate in the liver was comparatively high. These data demonstrate that the conjugation of bile acids greatly facilitates their secretion into bile.

Reaction of Alantolactone, an Allergenic Sesquiterpene Lactone, with some Amino Acids. Resultant Loss of Immunologic Reactivity

1974 ◽  
Vol 52 (7) ◽  
pp. 575-581 ◽  
Author(s):  
G. Dupuis ◽  
J. C. Mitchell ◽  
G. H. N. Towers
Keyword(s):  
Amino Acids ◽  
Contact Dermatitis ◽  
Sesquiterpene Lactone ◽  
Sesquiterpene Lactones ◽  
Sulfhydryl Group ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Amino Group ◽  
Michael Type Addition ◽  
Methylene Group

A study of the reaction of a hapten, alantolactone, with some amino acids is reported. Previously, we have reported than an α-methylene group attached to the γ-lactone is the immunologic requisite of alantolactone and some other sesquiterpene lactones. Such a group is known to be capable of undergoing "Michael-type addition" with the sulfhydryl group of cysteine. We confirm this finding and report that alantolactone can also undergo addition with the imidazole group of histidine and with the ε-amino group of lysine, but not with the guanido group of arginine, the hydroxyl group of serine, or the thio ether function of methionine. We selected these amino acids for further study because of their nucleophilic side chain. Samples of alantolactone that have undergone such addition no longer produce allergic eczematous contact dermatitis, as measured by patch test.

Synthesis of New 7-Alkylated Theophyllines by Chemical Modification of Dyphylline

2001 ◽  
Vol 2001 (4) ◽  
pp. 129-130 ◽  
Author(s):  
El Sayed H. El Ashry ◽  
Nagwa Rashed ◽  
Laila F. Awad ◽  
Adel A.H. Abdel-Rahman ◽  
Hanna A. Rasheed
Keyword(s):  
Chemical Modification ◽  
Side Chain ◽  
Cyclic Compounds ◽  
Methylene Group

Chemical modification of the propyl side chain of 7-(2,3-dihydroxyprop-1-yl)theophylline led to a variety of hetero-cyclic compounds linked to the theophylline by a methylene group.

Aspartame dipeptide analogues: effect of number of side-chain methylene group spacers and Cα-methylation in the second position

1997 ◽  
Vol 8 (8) ◽  
pp. 1305-1314 ◽  
Author(s):  
Eric Mossel ◽  
Fernando Formaggio ◽  
Marco Crisma ◽  
Claudio Toniolo ◽  
Quirinus B. Broxterman ◽  
...  
Keyword(s):  
Side Chain ◽  
Dipeptide Analogues ◽  
Methylene Group

scholarly journals Ethyl 2-{[2-(2-ethoxy-2-oxoethoxy)quinolin-4-yl]carbonyloxy}acetate

IUCrData ◽  
2018 ◽  
Vol 3 (10) ◽  
Author(s):  
Younos Bouzian ◽  
Fouzia Hlimi ◽  
Nada kheira Sebbar ◽  
Mohamed El Hafi ◽  
Brahim Hni ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Side Chain ◽  
Axis Direction ◽  
Π Interactions ◽  
Compound C ◽  
Group Form ◽  
Methylene Group

The conformation of the 2-ethoxy-2-oxoethoxy side chain, including a gauche Ce—O—C—C3 [72.46 (16)°] (e = ethoxy) unit, in the title compound, C18H19NO7, is partly determined by an intramolecular C—H...O hydrogen bond. In the crystal, C—H...O hydrogen bonds and C—H...π interactions arising from the same methylene group form chains extending along the a-axis direction.

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