Xanthones and a benzophenone from the roots of Pentadesma butyracea and their antiproliferative activity

A xanthone, 3,4-dihydro-8,10,12-trihydroxy-2,2-dimethylpyrano[2,3-b]xanthen-11(2H)-one (1), together with the known 30-epi-cambogin, 1,7-dihydroxyxanthone and 1,5-dihydroxyxanthone were isolated from the roots of Pentadesma butyracea Sabine. Their structures were established by high-field NMR techniques and EIMS. The antiproliferative activities of the EtOAc extract and the compounds were evaluated against Drosophila S2 cells and two human cancer cell lines, THP-1 (leukemia) and HCT116 (colon cancer).