Biosynthesis of anthracycline antibiotics by Streptomyces galilaeus. II. Structure of new anthracycline antibiotics obtained by microbial glycosidation and biological activity.

New anthracycline antibiotics derived from epsilon-, gamma- and beta-rhodomycinones and epsilon-isorhodomycinone by the microbial glycosidation using an aclacinomycin-negative mutant, the strain KE303, of Streptomyces galilaeus MA144-M1 were studied to elucidate their structures and biological activities. These antibiotics were the products in which the anthracyclinones added as precursors were linked at C-7 or C-10 position with the same trisaccharide moiety (cinerulosyl-2-deoxyfucosyl-rhodosaminyl group) as in the parental antibiotic aclacinomycin A. In addition to antimicrobial activity, they exhibited the growth inhibition of cultured L1210 leukemia cells and the marked inhibition against DNA and RNA synthesis.