Demethyl mutactimycins, new anthracycline antibiotics from Nocardia and Streptomyces strains

Abstract

New anthracycline antibiotics 3'-O-demethyl mutactimycin and 4-O,3'-O-didemethyl mutactimycin were isolated from two actinomycetes strains, Nocardia transvalensis and Streptomyces sp. GW 60/1571. The chemical structures were elucidated by mass spectrometry and NMR spectroscopy. Antibiotic 3 displayed moderate antimicrobial activity against Gram-positive bacteria and cytotoxicity against P388, L1210 and HeLa tumor cells (IC50; 9.6, > 25 and 20 μg/ml, respectively).