[Physico-chemical characteristics of the new antitumor antibiotic virenomycin].

Virenomycin, a new crystalline antitumor antibiotic was isolated from the mycelium of Streptomyces virens. The antibiotic contained: C 64.87 per cent, H 5.66 per cent, methoxylic groups 9.5 per cent. The melting temperature was 255-260 degrees (dec.), [alpha]20D=-17 (c 0.142, chloroform). Virenomycin had a complex UV spectrum with lambdamax. 245 (677), 265 (453), 275 (542), 287 (507), 395 (222) nm. A chromofor fragment and carbohydrate (C7H14O5) were found in the methanolysis products. Virenomycin was close to antibiotic c B-21085 BY THe physico-chemical properties and differed from it in the character of the UV spectrum and the values of the specific absorption, as well as by the optic rotation in dimethyl sulphoxide and acetic acid.