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C Mitra

Publications and source records attributed to C Mitra.

28 records · Page 2Linked to original sources
PubMed1978

Molecular orbital studies on the structure of nucleoside analogs. I. Conformation of 8-azapurine nucleosides.

PCILO (perturbative configuration interaction using localized orbitals) computations have been carried out for the conformational properties of 8-azapurine nucleosides. The results indicate an anti conformation for Xcn and a gg conformation for phiC(4')-C(5') for C(2')-endo 8-aza analogs compared to the syn and gg conformation for the corresponding purine nucleosides. For C(3')-endo sugar puckering, both molecules prefer the syn conformation due to intramolecular hydrogen bonding between O(5')-H of the sugar and N(3) of the base, the preference being more profound in 8-aza analogs. The crystallographic conformation 8-azaadenosine has been attributed to crystal forces. The available NMR data on 8-azapurine nucleosides are in agreement with the PCILO predictions.

Adenosine↗
PubMed1978

Inhibition of rat liver mitochondrial monoamine oxidase by chloramphenicol and 2-amino-1-p-nitrophenylpropane-1,3-diol.

Inhibition of rat liver mitochondrial monoamine oxidase by chloramphenicol and its hydrolytic product, 2-amino-1-p-nitrophenylpropane-1,3-diol, was studied. The enzyme activity and its inhibition by these two compounds were optimum at pH 7.0 after preincubation for 60 min, the time needed for maximum enzyme--inhibitor complex formation. Enzyme activity could be restored after prolonged dialysis. Monamine oxidase inhibition by chloramphenicol and its hydrolytic product was noncompetitive and reversible. Deamination of various monamines was not to the same degree by these compounds. Of the different antimicrobials studied, only chloramphenicol and its hydrolytic produced has a strong inhibitory effect on monoamine oxidase.

Animals↗
PubMed1977

Smooth muscle relaxant properties and vasomotor actions of 2-amino-1-p-nitrophenylpropane-1,3-diol.

Experiments with the guinea pig ileum, trachea, and vas deferens, the rat fundal strip, the rabbit jejunum and aortic strip, and the toad heart indicated that 2-amino-1-p-nitrophenylpropane-1,3-diol, the hydrolytic product of chloramphenicol, inhibited smooth muscles. Its action was direct and not through any mediators. After intravenous administration, the compound produced vasodepression followed by an overshooting rise of blood pressure. Vasodepression was not mediated by adrenergic, cholinergic, or histaminergic mechanisms. Hypertension was a sympathomimetic effect. Muscle relaxant and cardiovascular effects of the compound were similar to those of chloramphenicol, although it had no antibacterial effect.

Animals↗
PubMed1976

Muscle relaxant properties of chloramphenicol.

Experiments with the guinea pig ileum, guinea pig trachea, rat fundal strip, rat colon, rat vas deferens, and toad heart indicated that chloramphenicol inhibited smooth muscles, decreasing both the height and frequency of spontaneous contraction. Chloramphenicol-induced relaxation was not mediated through adrenergic, cholinergic, or histaminergic mechanisms. The degree of muscle relaxation was related to the concentration of chloramphenicol, and the relaxant effect could be reversed by removing chloramphenicol from site of action by washing. Its action appears to be direct on the muscle, possibly by interfering with the energy-generating mechanism.

Animals↗