Cytotoxic rearranged angucycline glycosides from deep sea-derived Streptomyces lusitanus SCSIO LR32

Two new rearranged linear angucycline glycosides, designated grincamycins G and H ( 1 and 2 ), together with three known congers P-1894B (vineomycin A 1 , 3 ), saquayamycin B ( 4 ) and vineomycin B 2 ( 5 ), were obtained from marine-derived actinomycete Streptomyces lusitanus SCSIO LR32. The structures of 1 and 2 were elucidated by MS, 1D and 2D NMR techniques. Compounds 2 – 5 showed significant inhibitory effect on Jurkat T-cell proliferation with IC 50 values of 3.0, 0.011, 0.037 and 0.3 μ M , respectively.