Cytotoxic flavonoids from two species.

A new isoflavone, 4'-prenyloxyvigvexin A () and a new pterocarpan, (6a,11a)-3,8-dimethoxybitucarpin B () were isolated from the leaves of and the stem bark of , respectively. The extract of also gave four known isoflavones, maximaisoflavone H, 7,2'-dimethoxy-3',4'-methylenedioxyisoflavone, 6,7,3'-trimethoxy-4',5'-methylenedioxyisoflavone, durmillone; a chalcone, 4-hydroxylonchocarpin; a geranylated phenylpropanol, colenemol; and two known pterocarpans, (6a,11a)-maackiain and (6a,11a)-edunol. (6a,11a)-Edunol was also isolated from the stem bark of . The structures of the isolated compounds were elucidated by spectroscopy. The cytotoxicity of the compounds was tested by resazurin assay using drug-sensitive and multidrug-resistant cancer cell lines. Significant antiproliferative effects with IC values below 10 μM were observed for the isoflavones 6,7,3'-trimethoxy-4',5'-methylenedioxyisoflavone and durmillone against leukemia CCRF-CEM cells; for the chalcone, 4-hydroxylonchocarpin and durmillone against its resistant counterpart CEM/ADR5000 cells; as well as for durmillone against the resistant breast adenocarcinoma MDA-MB231/ cells and resistant gliobastoma U87MGΔ cells.