Two new carbazole alkaloids designated as koenigine-quinone A and koenigine-quinone B were isolated from the alcoholic extract of the stem bark of Murraya koenigii and their structures were established as 7-methoxy-3-methylcarbazole-1,4-quinone and 6,7-dimethoxy-3-methylcarbazole-1,4-quinone, respectively, from spectral data and synthetic evidences. (C) 1998 Elsevier Science Ltd. All rights reserved.