Four new carbazole alkaloids (1-4) and fourteen known carbazole alkaloids (5-18) were isolated from Murraya koenigii. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 4, 6, 16, and 17 (10 mu M) had moderate hepatoprotective activities against D-galactosamine-induced HL-7702 cell damage. Compounds 11, 12 and 18 showed significant PTP1B inhibitory activity with IC50 values of 1.773, 1.875 and 2.286 mu M, respectively. (c) 2013 Elsevier B.V. All rights reserved.