Abstract
An aclacinomycin-negative mutant strain KE303 which required aklavinone aglycone for the production of anthracycline antibiotics was derived from Streptomyces galilaeus, and employed for the glycosidation of various anthracyclinones. ε-, γ- and β-Rhodomycinones, ε-isorhodomycinone, ε- and β-pyrromycinones and chemically modified aklavinones were found to be glycosidated to the biologically active anthracyclines, when they were fed to the growing culture. However, the feeding of daunomycinone, 13-deoxydaunomycinone, adriamycinone and steffimycinone did not yield any glycoside. The bioconversion of presumptive precursor glycosides revealed that aclacinomycin A is biosynthesized by the step-wise glycosidation from aklavinone via aklavin and MA144 S1.