New Angucycline Glycosides from a Marine-Derived Bacterium Streptomyces ardesiacus .

Chemical investigation of the ethyl acetate extract from the culture broth of the marine-derived actinobacterium Streptomyces ardesiacus 156VN-095 led to the isolation of three hitherto undescribed angucycline glycosides, including urdamycins W and X ( 1 and 2 ) and grincamycin U ( 9 ), as well as their seven known congeners. The structures of the new compounds were elucidated by means of spectroscopic methods (HRESIMS, 1D and 2 D NMR) and comparison of their experimental data with literature values. Compounds 1 - 3 and 9 were evaluated for their anti-Gram-positive bacterial effect and cytotoxicity against six cancer cell lines. Compound 1 displayed significant cytotoxicity against all the tested cell lines with GI 50 values of 0.019-0.104 µM. Collectively, these findings highlight the potential of angucycline glycosides as leading structures for the development of new anti-cancer drugs.