Constituents of the Roots of <i>Clausena lansium</i> and Their Potential Anti-inflammatory Activity

Abstract

Eight new carbazole alkaloids, claulamines C (1), D (2), and E (5) and clausenalines B-F (3, 4, 6-8), four new coumarins, clausemarins A-D (9-12), and 43 known compounds were isolated from the roots of Clausena lansium. The structures of the new compounds were established on the basis of 2D-NMR spectroscopic analysis, and their absolute configurations were established from their ECD spectra. The configuration of wampetin was revised as E using a NOESY experiment. Most of the isolated compounds were evaluated for their potential anti-inflammatory activity. The results showed that compounds 9, 13-18, and 20-22 exhibited strong inhibition of superoxide anion generation with IC50 values ranging from 1.9 to 8.4 μM, while compounds 18, 19, and 21 inhibited elastase release with IC50 values in the range from 2.0 to 6.9 μM.