Constituents of the roots of Clausena lansium and their potential anti-inflammatory activity

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 IC ₅₀ 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.