Aceriphyllic acid A, A new ACAT inhibitory triterpenoid, from Aceriphyllum rossii.

Two new triterpenoids along with three known ones, 3-oxoolean-12-en-27-oic acid (1), 3alpha-hydroxyolean-12-en-27-oic acid (2) and 3beta-hydroxyolean-12-en-27-oic acid (3), were isolated from Aceriphyllum rossii. The structures of the new compounds were determined to be a 3alpha,23-dihydroxyolean-12-en-27-oic acid (4) and a 3alpha,23-dihydroxyolean-12-en-29-oic acid (5) by spectroscopic and chemical methods; they were designated aceriphyllic acids A and B, respectively. Compounds 2, 3 and 4 remarkably inhibited the activity of ACAT.