Constituents of Eugenia sandwicensis with potential cancer chemopreventive activity

A triterpenoid. 3 beta -cis-p-coumaroyloxy-2 alpha ,23-dihydroxyolean-12-en-28-oic acid (1), and two natural products, 3 beta -trans-p-coumaroyloxy-2 alpha ,23-dihydroxyolean-12-en-28-oic acid (2) and 23-trans-p-coumaroyloxy-2 alpha ,3 beta -dihydroxyolean-12-en-28-oic acid (3). were isolated from a chloroform-soluble extract of the stems of Eugenia sandwicensis, along with 10 known compounds. Of these compounds. 2 showed significant inhibitory activity (79.2% at 4 mug/ml) in a 7,12-dimethylbenz[a]anthracene-induced mouse mammary organ culture assay system of relevance to cancer chemoprevention. Gallic acid was isolated as an antioxidative constituent of an ethyl acetate-soluble extract of E. sandwicensis stems. Isolates 1-3 were characterized on the basis of spectral and chemical evidence. (C) 2001 Elsevier Science Ltd. All rights reserved.