A bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana resulted in the isolation and characterization of two new triterpenoids, 23-trans-p-coumaroyloxy-2alpha,3alpha-dihydroxyolean-12-en-28-oic acid (1), and 23-cis-p-coumaroyloxy-2alpha,3alpha-dihydroxyolean-12-en-28-oic acid (2), along with seven known triterpenoids (3-9). The structures of the new compound...