[Determination of nystatin component composition using HPLC and TLC with densitometry]. / Opredelenie komponentnogo sostava nistatina metodami VEZhKh i TSKh s ispol'zovaniem densitometrii.

The component composition of nystatin produced by an improved strain of Streptomyces noursei was determined by HPLC on Milichrom chromatograph (USSR). It was shown that the antibiotic consisted of nystatins A1, A2, A3 and B and admixture substances. The data appeared to be in good agreement with the results of the complex TLC investigation, by using densitometry. The component composition of the samples was evidenced by SIEAP mass spectrometry. Physiochemical and biological characteristics of separate components are presented.

[Study of components of standard samples of polyene macrolide antibiotics by the methods of high performance liquid chromatography and SIEAP mass spectrometry]. / Izuchenie komponentnogo sostava standartnykh obraztsov polienovykh makrolidnykh antibiotikov metodom vysokoéffektivnoi zhidkostnoi khromatografii i mass-spektrometrii ERIAD.

The component composition of reference samples of polyenic macrolide antibiotics such as nystatin, mycoheptin, amphotericin B and levorin was studied by HPLC and chromatographic mass spectrometry in comparison to the WHO standards. It was shown that the samples were close by their component composition to the analogous samples of the WHO standards.

[Structure of pentaene antibiotic lavendofuseomycin]. / Struktura pentaenovogo antibiotika lavendofuzeomitsina.

By its UV spectrum lavendofuseomycin, a macrolide pentaene antibiotic, was referred to the subgroup of adeopentaenes with the spectral symmetrical patterns. The antibiotic contains a carbonyl, the end and 4 isolated double bonds and hemiketal ring. The molecule is lacking sugar. After the hydroantibiotic oxidation 2-methylhexadecane dicarboxylic and 4'-methyloctanoic acids were isolated. The antibiotic carbon skeleton was asserted on the basis of the mass spectral analysis of the products of the antibiotic complete reduction and the products of the antibiotic retroaldol cleavage. Determination of the position of the isolated double bonds, localization of chromophore, oxygen functions and the position of the amino group in the molecule resulted from investigation of the antibiotic azonolysis products.

[Azo derivatives of levorin]. / Azoproizvodnye levorina.

Levorin, an aromatic heptaenic antibiotic and sodium nitrite in solution of acetic acid formed a diazo compound. In the diazo reaction this compound interacted with beta-napthol or H-acid. The resulting azo compounds were readily soluble in organic solvents. In water their nitrites formed true solutions. The biological activity of the azo levorins was 100-200 times lower than that of the initial levorin. The physico-chemical characteristics of the azo levorins are presented.

[Effect of antioxidants and complexons on the stability of the microbiological standard for mycoheptin]. / Izuchenie vliianiia antioksidantov i kompleksonov na stabil'nost' mikrobiologicheskogo standarta mikogeptina.

Stability is one of the most important indices of the quality of antibiotic microbiological standards. At present the expiry date of the mycoheptin standard (a specially purified preparation) is 1 year when stored in sealed ampoules in an inert gas at a temperature of -20 degrees C. To prolong the expiry date of the standard the effect of various antiohidants and complexons on its stability was studied with the method of "accelerated aging". Sodium hexametaphosphate and Trilon B were tested as complexing agents and propyl gallate, ionol, N-phenyl-2-napththyl amine, mannitol and their mixtures were tested as antioxidants. The substances were applied in an amount of 3 per cent of the antibiotic weight. The favourable effect of the complexons on mycoheptin stability was shown. Their stabilizing effect was potentiated by addition of certain antioxidants.

[Physiochemical properties of LIA-0191 A and B antibiotics]. / Fiziko-khimicheskie svoistva antibiotikov LIA-0191 A i B.

An antifungal antibiotic LIA-0191 was isolated from the mycelium by methanol extraction. It was shown with thin-layer chromatography that it consisted of components A and B. Component A was isolated with collumn chromatography on silica gel, recrystalization from the solvent mixture as a monocomponent crystalline substance. On the basis of the physicochemical and biological properties it was identified with sentacidin. Component B was obtained from preparation LIA-0191 by the method of counter-current distribution and recrystalization from methanol. Comparison of its physico-chemical and biological properties with those of the known purines and pyrimidine pyrrol showed that antibiotic LIA-0191 B is new.

[Isolation and physicochemical characteristics of antibiotics from the LIA-0773 and LIA-0780 s trains]. / Vydelenie i fiziko-khimicheskaia kharakteristika antibiotikov iz shtammov LIA-0773 i LIA-0780

Individual components of the antibiotics from strains LIA-0773 and LIA-0708 were isolated with the method of counter-current distribution. Physico-chemical and biological properties of these substances were studied. It was shown that the substances differed from each other and chondamycin, and antifungal antibiotic by the values of their chromatographic mobility, physico-chemical and biological properties.

[Comparative characteristics of some actnomycetes, producers of antifungal antibiotics related to chondamycin]. / Sravnitel'naia kharakteristika nekotorykh aktinomitsetov--produtsentov protivogribkovykh antibiotikov, rodstvennykh khondamitsinu

Three actinomycetous strains designated as LIA-0773, LIA-0783 and LIA-0780 were isolated from various soil samples. The cultures actively inhibited the growth of Trichophyton gipseum and produced a non-polyenic antibiotic of the chondamycin type. The strains were identified with Act. griseochromogenes Fukunaga et. al., 1955. The cultures differed within the species by some morphological, cultural, physiological and antibiotic properties, as well as by the component composition of the antibiotic produced. Thus, strain LIA-0773 had larger spiral sporophores, satisfactorily hydrolized starch and inverted sucrose. The strain inhibited the growth of not only the fungi but also grampositive bacteria and mycobacteria and produced an antibiotic composed of 6 components. Strain LIA-0780 had small sporophores with close spirals and low amilolytic activity. It inhibited only the growth of the fungi and produced a monocomponent antibiotic. Strain LIA-0783 was intermediate. By its biological properties it was closer to strain LIA-0780. The antibiotic produced by it consisted of 6 components, while by its physico-chemical properties the antibiotic was close to that produced by strain LIA-0780. All the 3 actinomycetous cultures were considered as different variants of Act. griseochromogenes Fukunaga et al., 1955.