Actinoplanones A and B, new cytotoxic polycyclic xanthones from Actinoplanes sp.


Two new cytotoxic polycyclic xanthones, actinoplanones A (1) and B (2) were isolated from the culture broth of Actinoplanes sp. R-304 by monitoring their bioactivity against HeLa cells. Compound 1 was extremely cytotoxic (IC50 0.00004 micrograms/ml) against HeLa cells. The structures of 1 and 2 were established mainly by analyses of 2D heteronuclear… (More)