Clauemarazoles A-G, seven carbazole alkaloids from the stems of Clausena emarginata

Seven new carbazole alkaloids, clauemarazoles A-G, together with 19 known analogues were isolated from the stems of Clausena emarginata. Their structures were established on the basis of spectroscopic analyses, and the absolute configurations of compounds 1a, 1b, 5a, and 5b were confirmed by their ECD spectroscopy. Compounds 4, 13, 15, and 17 exhibited inhibitory abilities on LPS-induced NO production. Compounds 10-12, 20, 22, and 24 displayed hepatoprotective effects against DL-galactosamine-induced damage in WB-F344 cells. (C) 2015 Elsevier B.V. All rights reserved.