Synthesis and cytotoxicity of 1,6,8,9-substituted α-carboline derivatives.

α-Carboline (pyrido[2,3-b]indole) was selected as the basic scaffold for development of antileukemic agents by structural modification. From the structure-activity study, it was found that sequential introduction of 6-acetyl and 9-substituted benzyl groups onto an α-Carboline scaffold resulted in 6-acetyl-9-(3,5-dimethoxybenzyl)-9H-pyrido[2,3-b]indole and 6-acetyl-9-(3,4,5-trimethoxybenzyl)-9H-pyrido[2,3-b]indole with potent cytotoxicity against the HL-60 cell line. These two compounds will be used as new lead compounds for further investigation.