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Biomedical subjects

A S Mezentsev

Publications and source records attributed to A S Mezentsev.

13 recordsLinked to original sources

[Synthesis and study of the properties of (3S-trans)-3-amino-4-methylmonobactamic acid].

The process for production of (3S-trans)-3-amino-4-methylmonobactamic acid (3-AMMA) was studied. It included transformation of L-threonine into amide, protection and activation of the functional groups, cyclization of the resulting beta-mesyloxyacylsulfomate into azetidinone followed by removal of the protecting group. For estimation of the completeness of the process separate stages and their optimization chromatography and spectroscopy were used. Stability, optical activity and chromatographic mobility of 3-AMMA under various conditions were studied. It was shown that solutions of 3-AMMA were rather stable in weak acid and neutral media and degraded at pH greater than 9.0. Control of this process was provided by circular dichroism.

Anti-Bacterial Agents

[A method of quality control of 3-phenyl-5-methylisoxazole-4-carbonic acid chloranhydride using high performance liquid chromatography].

A method of quantitative determination of 3-phenyl-5-methyl-isoxazole-4-carbonyl chloride useful for its qualitative estimation at all stages of oxacillin industrial synthesis was developed. The methods is based on transformation of this semi-product into isopropyl ester followed by high efficiency liquid chromatography with the use of the "Milikhrom" chromatograph mad in the USSR. A variant of the typical method for determination of 3-phenyl-5-methyl-isoxazole-4-carbonyl chloride concentration in solution is described.

Animals

[Distribution of carbenicillin, benzylpenicillin and phenylmalonic acid in an organic solvent-water system].

Distribution of carbenicillin, benzylpenicillin and phenylmalonic acid in butyl acetate-water and methylene chloride-water systems within wide ranges of pH of the aqueous phase was studied. The experimental data were reviewed taking into account the distribution between the phases of the compound molecules and dissociation of the acids in the aqueous solution. The distribution constants of the compound molecules were calculated to be 37 (the literature data), 11.6 and 5.2 for every antibiotic respectively in the first system and 10 and 0.24 for carbenicillin and benzylpenicillin in the second system (the value for phenylmalonic acid was not calculated). When the concentration of carbenicillin in butyl acetate is high, dimerization of the acid molecule in the nonaqueous phase should be taken into the account. The dimerization constant is equal to 16.6 M-1.

Carbenicillin