Abstract
The detection, fermentation, isolation, physicochemical and biological properties of violamycin, a new antibiotic produced by a strain of Streptomyces violaceus IMET JA 6844 are described. Violamycin is a mixture of the complexes violamycin A and violamycin B. Violamycin A is mainly a complex of aminoglycosides of ϵ‐isorhodomycinone, β‐rhodomycinone, and α~2~‐rhodomycinone. The sugar component is rhodosamine. Violamycin B is mainly a complex of di‐ and triglycosides of ϵ‐isorhodomycinone, β‐rhodomycinone, and α~2~‐rhodomycinone. The sugar components of the diglycoside are rhodosamine and deoxy‐L‐fucose, the sugar components of the triglycoside are rhodosamine, deoxy‐L‐fucose, and rhodinose. Violamycin complexes A and B consist of constituents which are similar to other known members of anthracycline antibiotics but can be differentiated from them by physicochemical and biological properties, specially ϵ‐isorhodomycinone which so far has not been determined as a constituent of an antibiotic. The producer of violamycin was detected by means of the “BIP” test method. Violamycin can be isolated from fermentation filtrates and mycelium by extraction with lower aliphatic alcohols and can be purified by gel filtration methods. Violamycin has indicator properties and has been shown to possess a strong antimicrobial activity against grampositive bacteria and mycobacteria, including such strains which produce inactivating enzymes for different commercial antibiotics. Violamycin has growth inhibiting activity to a lower extent also in respect of gramnegative bacteria but has no antibiotic action in respect of yeasts and fungi. In addition to its antimicrobial activity, violamycin shows cytostatic action on mammalian cells in vitro and experimentally induced tumors of the mouse. Violamycin inhibited bacterial viruses in their multiplication by intracellular action without simultaneous blocking of the metabolism and growth of the host cells. The LD~50~ of violamycin A in mice was 15 mg/kg when administered intraperitoneally and 2 mg/kg on intraperitoneal administration of violamycin B.