Terpenoid constituents of Abies chensiensis with potential anti-inflammatory activity.

Six new triterpenes (neoabieslactones A-F, 1-6) and 17 known compounds were isolated from the aerial parts of Abies chensiensis. The structures of the new triterpenes were proposed by 1D and 2D NMR spectroscopy. Compound 1 was confirmed structurally by X-ray crystallography. In a bioassay against LPS-induced NO production in RAW264.7 macrophages, three compounds, neoabieslactone E (5), (12R,13R)-8,12-epoxy-14-labden-13-ol (7), and manool (8), exhibited IC(50) values of 9.1, 1.9, and 9.6 microg/mL, respectively.