A new prenylated stilbene, mappain (1), was isolated from leaves of Macaranga mappa by bioassay-guided fractionation. The structure was established by application of spectroscopic methods. Mappain is cytotoxic but it appears to be a poor substrate for P-glycoprotein-mediated transport because it is
Bioassay-guided fractionation of an extract of the fruit of Macaranga alnifolia from Madagascar led to the isolation of four new prenylated stilbenes, schweinfurthins E-H (1-4), and one new geranylated dihydroflavonol, alnifoliol (5). The known prenylated stilbene vedelianin (6) and the known