Cytotoxic constituents from Butea superba Roxb

A carpin (3-hydroxy-9-methoxypterocarpan) (Medicarpin) (1) and four isoflavones, 7-hydroxy-4'-methoxy-isoflavone (Formononetin) (2); 7,4'-dimethoxyisoflavone (3); 5,4'-dihydroxy-7-methoxy-isoflavone (Prunetin) (4) and 7-hydroxy-6,4'-dimethoxyisoflavone (5) were isolated from the tuber roots of Butea superba Roxb. Compounds 2 and 4 showed moderate cytotoxic activity on KB cell lines with IC(50) (microM) values of 37.3+/-2.5 and 71.1+/-0.8 and on BC cell lines with IC(50) (microM) values of 32.7+/-1.5 and 47.3+/-0.3, respectively.