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 IC50 values of 3.0, 0.011, 0.037 and 0.3 mu M, respectively.