Isolation, structure, and bioactivities of abiesadines A-Y, 25 new diterpenes from Abies georgei Orr

Twenty-five new (abiesadines A-Y, 1-25) and 29 known (26-54) diterpenes were isolated from the aerial parts of Abies georgei. Abiesadine A ( 1) is a novel 8,14-seco-abietane, while abiesadine B ( 2) is a novel 9,10-seco-abietane. The structures of the new compounds were established on the basis of spectroscopic data analysis. Manool ( 52) showed the strongest effect against LPS-induced NO production in RAW264.7 macrophages with the IC50 value of 11.0 mu g/mL. In another anti-inflammatory assay against TNF alpha-triggered NF-kappa B activity, (12R, 13R)-8,12-epoxy-14-labden-13-ol ( 54) exhibited the strongest effect (IC50 = 8.7 mu g/mL). For antitumor assays, pomiferin A (26) and 8,11,13-abietatriene-7 alpha, 18-diol (29) both showed the most significant activity against LOVO cells (IC50 = 9.2 mu g/mL). While 7-oxocallitrisic acid ( 46) exhibited significant cytotoxicity against QGY-7703 tumor cells (IC50 = 10.2 mu g/mL). Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.