SUBSTITUTED 2,5'-BI-1H-BENZIMIDAZOLES - TOPOISOMERASE-I INHIBITION AND CYTOTOXICITY

Several 2'-aryl-5-substituted-2,5'-bi-1H-benzimidazole derivatives wer e synthesized and evaluated as topoisomerase I poisons and for their c ytotoxicity toward the human lymphoblast cell line RPMI 8402. This stu dy focused on 18 2,5'-bi-1H-benzimidazole derivatives which contained either a 5-cyano, a 5-(aminocarbonyl), or a 5-(4-methylpiperazinyl) gr oup. Among these bibenximidazoles, the pharmacological activity of 2'- phenyl derivatives and the influence of the different positional isome rs of either a 2'-tolyl group or a 2'-naphthyl moiety on cytotoxicity and topoisomerase I inhibitory activity were determined.