New abietane diterpenoids from the cones of Larix kaempferi

A new podocarpane diterpene, 7α,15-dihydroxypodocarp-8(14)-en-13-one (1) and eight new abietane diterpenes, abiet-8(14)-en-7α,13β,15,18-tetraol (2), 7α,13β,15-trihydroxyabiet-8(14)-en-18-oic acid (3), 13β,18-dihydroxyabiet-8(14)-en-7-one (4), 13β,15,18-trihydroxyabiet-8(14)-en-7-one (5), 7-oxo-13β-methoxyabiet-8(14)- en-18-oic acid (7), abiet-8(14)-en-7α,12α,13β,18-tetraol (8), 7α,12α,13β-trihydroxyabiet-8(14)-en-18-oic acid (9), and abiet-8(14)-en-7α,12α,13β,15,18-pentaol (10) were isolated from the CHCl3 extract of the cones of Larix kaempferi. Their structures were determined on the basis of chemical and spectral evidence. The inhibitory effects of compounds 1-4 and 7-9 on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), were examined for a primary screening for anti-tumor promotors. Key words: Larix kaempferi, Pinaceae, cones, abietane, EBV-EA.