[Studies on the triterpenes from Bemeuxia thibetica Decne].

Four triterpenes were isolated from the alcoholic extract of Bemeuxia thibetica Decne. A new triterpene, 16 alpha, 21 beta, 22 alpha, 28-tetrahydroxyolean-12-en-3-one, named bemeuxin (I), was identified on the basis of spectral evidences. The other three triterpenes were identified as 21-tigloylbarringtogenol C(II), 2 alpha, 3 alpha-dihydroxyursolic acid (III) and 2 alpha, 3 beta-dihydroxyursolic acid (IV).