Daturmetesides A-E, five new ergostane-type C28 sterols from the leaves of Datura metel L.

Five undescribed ergostane-type C₂₈ sterols, daturmetesides A-E (1-5), were isolated from the leaves of Datura metel L. The chemical structures of these new compounds were characterized through extensive spectroscopic analysis and comparison with literatures. Among them, the absolute structures of daturmetesides A and C were unambiguously determined by X-ray crystallography. The anti-inflammatory effect of daturmetesides A-E was all tested by measuring nitric oxide production in lipopolysaccharide-activated RAW264.7 cells. Daturmetesides A, C and D moderatelylowered the NO production with IC₅₀ values ranging from 17.05 ± 0.35 to 24.88 ± 0.93 μM.