Lignan Glycosides from Urena lobata.

Four new lignan glycosides; urenalignosides A-D (1-4), along with 12 known ones (5-16) were isolated from Urena lobata. Their structures were determined on the basis of extensive spectroscopic and spectrometric data (1D and 2D NMR; IR; CD; and HRESIMS). Compounds 2-4; 6; 7; 10; and 11 showed inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophage cells with IC₅₀ values in the range of 25.5-98.4 μM (positive control; quercetin; IC₅₀ = 7.2 ± 0.2 μM).