Bioactive triterpenoids from the stem bark of Picea glehni

Two new triterpenoids, 3 alpha -methoxyserrat-14-en-21 beta -yl formate (1) , and 24-methylcycloartenone (2), were isolated from the stem bark of Picea glehni (Fr. Schm.) Masters together with three known triterpenoids, 3-meth oxyserrat-14-en-21 beta -ol, 3 beta -methoxyserrat-14-en-21 beta -ol, and p iceanonol A. Compounds 1, 2, and a synthetic sample, 3 alpha -methoxyserrat -13-en-21 beta -yl formate showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O -tetradecanoylphorbol-13-acetate (TPA).