[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.