Inhibitory effects of compounds from Styrax obassia on NO production.

Two new benzofurans, 2-(3,4-dimethoxyphenyl)-5-(1,3-dihydroxypropyl)-7-methoxybenzofuran (1) and 2-(3,4-methylenedioxyphenyl)-5-(3-hydroxymethyletoxy-1-hydroxypropyl)-7-methoxybenzofuran (2), a new triterpene, 3β, 6β, 21β-trihydroxyolean-12-ene (3), and eleven known compounds were isolated from the stem bark of Styrax obassia. The structures of the isolated compounds were established by extensive spectroscopic analyses, including 1D and 2D NMR and HRMS. Their anti-inflammatory activities were evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages. Compound 1 was shown to reduce LPS-induced iNOS expression in a dose-dependent manner. In addition, pretreating cells with 1 significantly suppressed their LPS-induced expression of COX-2 protein.