Antiandrogenic phenolic constituents from Dalbergia cochinchinensis.

Four new compounds, 9-hydroxy-6,7-dimethoxydalbergiquinol, 6-hydroxy-2,7-dimethoxyneoflavene, 6,4'-dihydroxy-7-methoxyflavan and 2,2',5-trihydroxy-4-methoxybenzophenone, in addition to eight known phenolic compounds including 7-hydroxy-6-methoxyflavone, have been isolated from the stems of Dalbergia cochinchinensis. Their structures were established by spectroscopic techniques including one- and two-dimensional NMR methods. The first two compounds showed potent inhibitory activity towards 5 alpha-dihydrotestosterone (DHT) which binds with an androgen receptor to form a DHT-receptor complex that causes androgen-dependent disease.