Synthesis and antitumor activity of quaternary salts of 2-(2'-oxoalkoxy)-9-hydroxyellipticines

Various kinds of water-soluble quaternary salts of 2-(2'-oxoalkoxy)-9-hydroxyellipticines were synthesized in a search for compounds with potent antitumor activity and low toxicity. Some compounds exhibited more potent antitumor activities than elliptinium (1) and SUN 4599 (3). In particular, 2-(3'-methoxy-2'-oxopropanoxy)-9- hydroxy-5,11-dimethyl-6H-pyrido[4,3-b]carbazolium bromide (4d) showed potent antitumor activities against P388 leukemia, colon 26, and Lewis lung carcinoma.