Biologically active carbazole alkaloids from Murraya koenigii

The bioassay guided fractionation of the acetone extract of the fresh leave s of Murraya koenigii resulted in the isolation of three bioactive carbazol e alkaloids, mahanimbine (1), murrayanol (2), and mahanine (3), as confirme d from their H-1 and C-13 NMR spectral data. Compound 2 showed an IC50 of 1 09 mu g/mL against hPGHS-1 and an IC50 of 218 mu g/mL against hPGHS-2 in an tiinflammatory assays, while compound 1 displayed antioxidant activity at 3 3.1 mu g/mL. All three compounds were mosquitocidal and antimicrobial and e xhibited topoisomerase I and II inhibition activities.