Anti-inflammatory sesquiterpenoids from the leaves of Datura metel L.

Nine new (1-9) and three known (10-12) sesquiterpenoids were isolated from the ethanol-water (7:3, v/v) extract of the Datura metel L. leaves. The structures of 1-9 were elucidated by detailed spectroscopic analyses, including 1D and 2D NMR, HR-ESI-MS. All isolates (1-12) were evaluated for anti-inflammatory activity against the production of nitrogen oxide in lipopolysaccharide-induced RAW264.7 cells and compound 5 possessed the best inhibitory effect among them, with the IC₅₀ value reaching 9.33-11.67 μM, which was lower than positive control, L-NMMA, with IC₅₀ range from 13.64 to 17.02 μM.