Cytotoxic compounds of Physena madagascariensis from the Madagascar rain forest paragraph sign.

Two new flavanones, remangiflavanones D and E (1 and 2), were isolated from an extract of the twigs, leaves, and flowers of Physena madagascariensis together with three known flavanones, remangiflavanones A-C (3-5), and (E)-N-feruloyltyramine (6). The structures of the new compounds 1 and 2 were established on the basis of one-dimensional and two-dimensional NMR spectroscopic data interpretation. All compounds were evaluated for their cytotoxicity in the A2780 human ovarian cancer cell line. Compound 5 was the most active with an IC50 value of 2.5 microg mL-1.