Demethyl Mutactimycins, New Anthracycline Antibiotics from Nocardia and Streptomyces Strains

Abstract

New anthracycline antibiotics 3′-O-demethyl mutactimycin (3) and 4-O, 3′-O-didemethyl mutactimycin (4) 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).