NEW XANTHONES FROM GARCINIA BRACTEATA AND THEIR CYTOTOXICITIES

摘要

Two new xanthones, bracthones A (1) and B (2), together with four known xanthones (3-6) were isolated from the stems of Garcinia bracteata. Their structures were elucidated by spectroscopic methods, including extensive 1D-and 2D-NMR techniques. Compounds 1-6 were tested for their cytotoxicities against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7). Compounds 1 and 2 showed high cytotoxicities against PC3 cell with IC_(50) values of 3.24 and 2.15 μM, respectively.