[The structure of tripterygone]

Three triterpene compounds have been isolated from the roots of Tripterygium wilfordii Hook F. The structure of the new compound, 3-hydroxy-25-norfriedel-3, 1 (10)-dien-2-one-30 oic acid named tripterygone (III), and the identity of others, 3 beta, 22 beta-dihydroxy-delta 12-oleanen-29-oic acid (I) and 2 alpha, 3 alpha, 24-trihydroxy-delta 12-ursene-28-oic acid (II) have been established by spectral data and physical properties. Compound II was isolated for the first time from the title plant.