An antiproliferative xanthone of Symphonia pauciflora from the Madagascar rainforest.

Investigation of a Malagasy endemic plant identified as Symphonia pauciflora Baker (Clusiaceae) for antiproliferative activities against the A2780 ovarian cancer cell line led to the isolation of a new compound identified as 2-(3,3-dimethylallyl)-7-methoxy-l,5,6-trihydroxy-2",2"-dimethylpyrano(6",5":3,4) xanthone (1) and the two known guttiferones A (2) and I (3). The structure elucidation of 1 was based on the analysis of its 1D and 2D NMR and mass spectral data. Compound 1 showed good antiproliferative activity with an IC50 value of 3.