Nitric oxide inhibitory terpenes and its glycosides from Ainsliaea bonatii.

Seven new terpenes and its derivatives classified into a p-menthane glycoside (1), a guaianolide glycoside (2), three eudesmane and its glycosides (3-5), and two mono-terpene derivatives (9 and 10) were isolated from Ainsliaea bonatii, together with three known guaianolides (6-8). Their structures were elucidated by spectroscopic data analysis, and absolute configurations were determined by DP4+ probability analysis via calculated 13C NMR data of isomers. Compounds 6 and 9 showed nitric oxide (NO) inhibitory effects in LPS-induced RAW 264.7 macrophage cells with IC50 values of 9.3 and 10.6 μM, respectively.