Two new xanthones, a new lignin, and twenty phenolic compounds from Smilax china and their NO production inhibitory activities

Abstract

Two new xanthones smilone A (1), smilone B (2), and a new lignin smilgnin A (3) were isolated from the rhizomes of Smilax china L., together with three known xanthones (4–6), four lignins (7–10), two flavones (11, 12), two stilbenoids (13, 14), and ten organic phenoloids (15–24). Of them, compounds 4–6 were isolated from the genus Smilax for the first time. The structures of 1–24 were elucidated by the extensive analysis of spectral data and compared with the literature. All compounds were evaluated for their inhibitory effects against LPS-induced NO production in RAW264.7 macrophages. Among them, compound 24 exhibited significant inhibitory activity against NO production (IC50 = 1.26 µM), while compounds 3, 6, and 7 showed weak activities at the concentration of 50 μM.