Coumarins and carbazoles from Clausena excavata exhibited antimycobacterial and antifungal activities

Four known coumarins, dentatin (1), nor-dentatin (2), clausenidin (3) and xanthoxyletin (5), and six known carbazole derivatives, 3-formylcarbazole (6), mukonal (7), 3-methoxycarbonyl-carbazole (8), murrayanine (9), 2-hydroxy-3-formyl-7-methoxy-carbazole (10) and clauszoline J (11) were isolated from Clausena excavata. Compounds 1 and 6 were first isolated from the crude chloroform extract of the rhizomes. Compounds 1, 2, 3, 6, 7, 8, 10 and 11 showed anti- mycobacterial activity at a minimum inhibitory concentration (MIC) of 50,100, 200, 100, 200, 50, 100 and 100mug/mL, respectively. O-Methylated clausenidin (4), prepared from 3, exhibited anti mycobacterial activity at MIC 50 mug/mL. Compounds 6, 7, 8 and 10 showed antifungal activity with IC50 values of 13.6, 29.3, 9.5 and 2.8 mug/mL, respectively. All compounds demonstrated no cytotoxicity against KB and BC-1 cell lines.