9alpha,13alpha-Epidioxyabiet-8(14)-en-18-oic acid
9alpha,13alpha-Epidioxyabiet-8(14)-en-18-oic acid shows potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.