Triterpenoids from the Flower of Campsis grandiflora K. Schum. as Human Acyl-CoA: Cholesterol Acyltransferase Inhibitors

The flower of Campsis grandiflora K. Schum. was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and H2O. From the EtOAc fraction, seven triterpenoids were isolated through the repeated silica gel, ODS column chromatographies and preparative HPLC. From the result of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as 3β-hydroxyolean-12-en-28-oic acid (oleanolic acid, 1), 3β-hydroxyurs-12-en-28-oic acid (ursolic acid, 2), 3β-hydroxyurs-12-en-28-al (ursolic aldehyde, 3), 2α,3β-dihydroxyolean-12-en-28-oic acid (maslinic acid, 4), 2α,3β-dihydroxyurs-12-en-28-oic acid (corosolic acid, 5), 3β,23-dihydroxyurs-12-en-28-oic acid (23-hydroxyursolic acid, 6) and 2α,3β,23-thhydroxyolean-12-en-28-oic acid (arjunolic acid, 7). These teriterpenoids were isolated for the first time from this plant. Also, compounds 4, 5, 6, and 7 revealed relatively high hACAT-1 inhibitory activity with the value of 46.2±1.1, 46.7±0.9, 41.5±1.3 and 60.8±1.1% at the concentration of 100 μg/mL, respectively.