[Structure of the antineoplastic antibiotic variamycin].

The results of the structural study of antitumor antibiotic variamycin and its peracetyl derivative by 1H-and 13C-NMR spectroscopy are reported. Structures of carbohydrate chains of the antibiotics molecule are revised. Variamycin is shown to be 2-[beta-cymmarosyl(1-3)-beta-oliosyl (1-3)-beta-olivosyl]-6-[beta-olivosyl (1-3)-beta-olivosyl] chromomycinone.

[Azlocillin stability in solutions and the solid state].

Stability of azlocillin in aqueous solutions at pH 1.5-12.5 was studied at various temperatures.

[Process of sodium fusidate inactivation as affected by oxygen and humidity].

The effect of oxygen and moisture on stability of sodium fusidate was studied. It was shown that inactivation of the antibiotic in the atmosphere of oxygen was due to its oxidation in the preparations with low humidity levels. In the preparations with high humidity levels, the main cause of the antibiotic inactivation was hydrolysis with respect to C-16-O-acetyl group.

[Determination of the sulfate ion content in antibiotic sulfate salts by a complexometric titration method].

A possibility of assaying antibiotic sulfates, such as gentamicin, kanamycin, monomycin, neomycin, ristomycin, streptomycin, florimycin and polymyxin M sulfates for sulfate ions by titration with barium chloride in the presence of chlorphosphonaso-III, a metal indicator immediately in the salt solutions or after elimination of the cation by means of ion exchange (sulfocation exchange resins in H+-form) was tested. The procedure was shown to be adequate to the classical weight method.

[Development of an automated information retrieval system for the identification of antibiotics].

The basic points in the development of a specialized computer information search system providing ientification of new antibiotics at early stages of their investigation are described. The system of coding the physico-chemical properties of the agents and the spectra of their antimicrobial activity presenting the substance in the information bank is developed. The task of identification is to find in the reference bank according to some specially organized keys such antibiotics which are identical or close by their properties to the substance being identified.