The chemical investiation of the dried tubers of Butea superba Roxb. from Lampang province gave seven compounds from methanol crude extract. The structures of seven compounds were established on the basis of physical properties and spectroscopic data including 1D-NMR, 2D-NMR, MS and UV-Vis techniques. A mixture of steroids; including campesterol, stigmasterol and B-sitosterol(1), medicarpin (2), four isoflavones; prunetin (3), formononetin (4), 7-dydroxy-6-4'-dimethoxyisoflavone (5) and 7,4'-dimethoxyisoflavone (6), and hexacosanoic acid 2,3-dihydroxypropyl ester (7) were identified. Compound (2) and (3) were active against BC and KB cancer. IC50 value of compound (2) against BC and KC cancer were 12.9+0.3 and 19.2+0.8 ug/ml and IC50 value of compound (3) against BC and KC cancer were 8.8+1.5 and 10.0+2.5 ug/ml, respectively. They were active against NCI-H 187 cell line at concentration more than 20 ug/ml. Compound (1), (4), (5) and (6) were active against BC cell line, KB cell line and NCI-H 187 cell line at concentration more than 20 ug/ml, respectively.
