Activity-guided isolation of triterpenoid acyl CoA cholesteryl acyl transferase (ACAT) inhibitors from Ilex kudincha

Activity-guided fractionation of a methanol extract of the leaves of Ilex k udincha led to the isolation of seven acyl CoA cholesteryl acyl transferase (ACAT) inhibitory triterpenes. Four of them were identified by spectroscop ic methods as ulmoidol (4), 23-hydroxyursolic acid (5), 27-trans-p-coumaroy loxyursolic acid (6) and 27-cis-p-coumaroyloxyursolic acid (7), and three w ere new compounds named ilekudinols A-C (1-3). The structures of these new triterpenoids were elucidated as 2 alpha,3 beta-dihydroxy-24-nor-urs-4(23), 11-dien-28,13 beta-olide (1), 2 alpha,3 beta-dihydroxy-24-nor-urs-4(23), 12 -dien-28-oic acid (2), and 3 beta,24,28-trihydroxylupane (3). Compounds 1-7 showed potent inhibitory activity in the ACAT assay.