Resveratrol tetramers from Vatica diospyroides

Vatdiospyroidol (1), a novel cytotoxic resveratrol tetramer, was isolated f rom the stems of Vatica diospyroides Sym. (Dipterocarpaceae) by bioassay-gu ided fractionation monitored with a human oral epidermoid carcinoma (KB) ce ll line. Another novel resveratrol tetramer, vaticaphenol B (2), was obtain ed as a noncytotoxic constituent, along with the known compounds, bergenin, betulin, betulinic acid, mangiferonic acid, and (E)-resveratrol 3-O-beta-D -glucopyranoside. The structures of compounds 1 and 2 were elucidated by sp ectral analysis, including 1D and 2D NMR experiments, and by molecular mode ling.