Grincamycins I-K, Cytotoxic Angucycline Glycosides Derived from Marine-Derived Actinomycete Streptomyces lusitanus SCSIO LR32

Three new angucycline glycosides, designated grincamycin I ( 1 ), J ( 2 ), and K ( 3 ), together with the known congener A-7884 ( 4 ), were isolated from marine-derived actinomycete Streptomyces lusitanus SCSIO LR32. The structures of the new compounds were elucidated by comprehensive spectral data analysis. Compounds 2 and 4 exhibited antitumor activity against human cancer cells MDA-MB-435, MDA-MB-231, NCI-H460, HCT-116 and HepG2, and human normal breast epithelial cell MCF10A with IC (50) values ranging from 0.4 to 6.9 mu M. In addition, A-7884 ( 4 ) demonstrated antimicrobial activity against Micrococcus luteus with an MIC value of 1.95 mu g/mL.