Three new xanthones from the resin of Garcinia hanburyi.

Three new xanthones, 22,23-dihydroxydihydrogambogenic acid (1), 12-hydroxygambogefic acid A (2), and hanburixanthone (3), along with thirteen known compounds were isolated from the resin of Garcinia hanburyi. The structures of the new compounds were determined by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds. All compounds were tested for their cytotoxicities against A549, HCT116, and MDA-MB-231, and most of them showed significant effects on the cell lines.