An anti-inflammatory C-stiryl iridoid from Camptosorus sibiricus Rupr.

A new iridoid glycoside, named camptoside (1), together with three known compounds as dehydrodiconiferyl alcohol-9'-O-β-d-glucopyranoside (2), aesculetin (3) and vajicoside (4), have been isolated from Camptosorus sibiricus Rupr. (Aspleniaceae). Their structures were established on the basis of spectroscopic analysis, especially 1D- and 2D-NMR data, and by comparison of their spectroscopic and physical data with those reported in the literature. Compounds 1-3 exhibited inhibitions of nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages with IC₅₀ values of 11.2, 8.3 and 9.4 μM, respectively.