SIBIROMYCIN: ISOLATION AND CHARACTERIZATION

Abstract

Sibiromycin, possessing strong antitumor activity in animal experiments, is produced by Streptosporangium sibiricum. Sibiromycin can be isolated from culture filtrate using ion-exchange or by solvent extraction. The antibiotic was obtained as a crystalline substance with ultraviolet absorption maxima at 230 and 310 nm, [α]_D+525° (in dimethylformamide); the empirical formula-C₂₄H₃₁N₃O₇. In 1 N hydrochloric acid, sibiromycin is transformed into "the product of acidic inactivation" (PAI), C₂₄H₂₉N₃O₆. Hydrolysis of PAI with 6 NHC1 affords "the product of acidic hydrolysis" (PAH), C₁₆H₁₄N₂O₃. Methanolysis of sibiromycin and PAI yields the methylglycoside of a new amino sugar sibirosamine, C₈H₁₆NO₃ (OCH₃). Aqueous alkaline hydrolysis of PAI and PAH affords the crystalline substance C₈H₉NO.