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Biomedical subjects

A A Slavin

Publications and source records attributed to A A Slavin.

9 recordsLinked to original sources
PubMed1990

[Kinetics of thermal inactivation of oleandomycin in aqueous and native alkaline solutions].

The process of oleandomycin inactivation in aqueous alkaline solutions with their heating was studied by using the microbiological method of the antibiotic content assay. The initial specific rate of inactivation of crystalline oleandomycin in buffer solutions and oleandomycin in the fermentation broth filtrate was evaluated. It was shown that the inactivation was retarded by the reaction products and the components of the fermentation broth filtrate. The production rate of oleandomycin anhydro derivatives amounting to 3-40 per cent of the total mass of the inactivation product was estimated by UV spectrophotometry.

Alkalies↗
PubMed1990

[Study of oleandomycin extraction in a methylene chloride-aqueous medium system].

Influence of pH, temperature and oleandomycin concentration on distribution of the antibiotic in the methylene chloride-aqueous medium system was studied. It was shown that the oleandomycin distribution coefficient did not depend on the antibiotic concentration within the ranges of 2000 to 20,000 micrograms/ml. An equation defining relationship between the oleandomycin distribution coefficient and pH of the aqueous phase is presented.

Hydrocarbons, Chlorinated↗
PubMed1978

[Components of a native solution that displace the equilibrium distribution of oleandomycin during extraction].

A marked decrease in the coefficient of oleandomycin distribution in the system of the fermentation broth filtrate-butyl acetate was observed during the transfer from the 1st to the following extraction stages. It was supposed that the oleandomycin fermentation broth filtrate contained admixtures affecting significantly the antibiotic distribution between the aqueous phase and organic solvent.

Acetates↗
PubMed1978

[Separation of novobiocin, isnovobiocin and descarbamyl novobiocin by a thin-layer chromatographic method].

A thin-layer chromatographic method for separation of novobiocin, isonovobiocin and descarbamylnovobiocin using Silufol plates was developed. The method is simple and rapid. It provided clear separation of the components and using of diethyl ether, a simple individual separating solvent. The method allowed determination of novobiocin and the products of its isomerization in the fermentation broth, extracts and dry substances, as well as performance of operative control and regulation of the technological processes of fermentation and chemical purification of novobiocin.

Chromatography, Thin Layer↗
PubMed1978

[Increase in the oleandomycin distribution coefficient at the extraction stage by using electron carrier-acceptors].

A possibility of increasing the distribution coefficient of oleandomycin on its extraction from the aqueous solution into the organic phase containing an electron carrier-acceptor was shown. It was found that the level of the oleandomycin equilibrium shift into the organic phase depended on the carrier nature, i. e. the donor-acceptor interaction of the carrier and the antibiotic. It was shown that the oleandomycin fermentation broth contained non-identified admixtures, the interaction of which with the antibiotic was higher than its interaction with the acceptor-carriers tested.

Acetates↗
PubMed1977

[Ways to optimize the technological process of oleandomycin reextraction].

Dependence of the oleandomycin distribution coefficient on pH of the acqueous phase and temperature in the system of butylacetate extract-water acidified with orthophosphoric acid was studied. With a purpose of intensification of the process of oleandomycin reextraction, decreasing the antibiotic inactivation and evaporation of the organic solvent it was proposed to perfom oleandomycin extraction at pH 4.0--5.0 accompanied by simultaneous decreasing of the temperature.

Acetates↗
PubMed1977

[Study of the equilibrium conditions for the extractive purification of oleandomycin].

Dependence of the oleandomycin distribution coefficient on the antibiotic concentration, duration of the filtrate storage, extraction temperature and salting-out agents was studied. The distribution coefficient of oleandomycin in the system of fermentation broth filtrate--butylacetate was much lower (about 3 times) than that in the system of oleandomycin phosphate aqueous solution--butylacetate. Addition of sodium sulfate to the aqueous phase provided a significant increase in the oleandomycin distribution coefficient.

Acetates↗
PubMed1977

[Use of aluminum salts for purifying oleandomycin culture broth].

It was shown that "nepheline coagulant"--Al2 (SO4)3-18H2O was effective in coagulating the admixtures in oleandomycin fermentation broth. The use of the "nepheline coagulant" in an amount of 1 to 3 per cent (by the weight) of the volume of the oleandomycin fermentation broth provided butyl acetate extraction of the antibiotic without formation of stable emulsion. Addition of the "nepheline coagulant" in an amount of 1 to 2 per cent (by the weight) to the fermentation broth markedly increased the rate of the fermentation broth filtration.

Aluminum↗