Adamantyl derivatives and rearranged benzophenones from Garcinia xanthochymus fruits

Garcinia xanthochymus is a tropical fruit yielding tree native to South East Asia. Its fruit is used to treat bilious conditions, diarrhea and dysentery. In this study, three new adamantyl derivatives, two new rearranged benzophenones, named as garcixanthochymones A-E (1-5), together with 12 known compounds including 7 xanthones (6-12) and 5 flavonoids (13-17) were isolated from the fruits of G. xanthochymus. Their structures were elucidated by detailed spectroscopic analyses. All isolated compounds were evaluated for their anti-proliferative activities against four human tumor cells (HepG2, A549, SGC7901, MCF-7). Adamantyl derivatives (1-3) and rearranged benzophenones (4-5) displayed potential inhibitory activity against four human cancer cell lines with IC50 values of 5.16-16.45 mu M. These data suggested that the extracts of the fruits of G. xanthochymus are potent candidates for cancer prevention.