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 kudincha led to the isolation of seven acyl CoA cholesteryl acyl transferase (ACAT) inhibitory triterpenes. Four of them were identified by spectroscopic methods as ulmoidol (4), 23-hydroxyursolic acid (5), 27-trans-p-coumaroyloxyursolic acid (6) and 27-cis-p-coumaroyloxyursolic acid (7), and three were 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.