A New Carbazole Alkaloid from Murraya koenigii Spreng (Rutaceae)

A new carbazole alkaloid (kurryam) oxygenated at the 4-position, hitherto unknown among carbazole alkaloids, has been isolated from the seeds of an Indian medicinal plant, Murraya koenigii (Rutaceae). The structure has been established as 4-hydroxy-(2′,2′,3)-trimethyl-(6,7)-dimethoxy pyranocarbazole from extensive 2D NMR spectral studies. In addition, two known carbazole alkaloids, (2′,2′,3)-trimethyl 6-methoxy pyranocarbazole and (2′,2′,3)-trimethyl 6-hydroxy pyranocarbazole were isolated from the seeds of the same plant, of which (2′,2′,3)-trimethyl 6-methoxy pyranocarbazole exhibited significant antidiarrhoeal activity, as also did the new compound.