Bisabolane sesquiterpenes from Clausena sanki with their potential anti-inflammatory activities

The investigation on the stems and leaves of Clausena sanki led to the isolation of a previously undescribed bisabolane sesquiterpene, clausemargic A (1), together with six known analogues (2–7). The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. All known compounds (2–7) were isolated from C. sanki for the first time. All isolated compounds were evaluated for their anti-inflammatory activities via examining the inhibitory activity on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro. Compounds 1–7 showed significant inhibitory activities with IC50 values comparable to that of hydrocortisone.