Novel pyrazolo[3,4-d]pyrimidine with 4-(1H-benzimidazol-2-yl)-phenylamine as broad spectrum anticancer agents: Synthesis, cell based assay, topoisomerase inhibition, DNA intercalation and bovine serum albumin studies.

A series of new pyrazolo[3,4-d]pyrimidine possessing 4-(1H-benzimidazol-2-yl)-phenylamine moiety at C4 position and primary as well as secondary amines at C6 position has been designed and synthesized. Their antitumor activities were evaluated against a panel of 60 human cancer cell lines at National Cancer Institute (NCI). Six compounds displayed potent and broad spectrum anticancer activities at 10 μM. Compounds 8, 12, 14 and 17 proved to be the most active and efficacious candidate in this series, with mean GI50 values of 1.30 μM, 1.43 μM, 2.38 μM and 2.18 μM, respectively against several cancer cell lines. Further biological evaluation of these compounds suggested that these compounds induce apoptosis and inhibit human topoisomerase (Topo) IIα as a possible intracellular target. UV-visible and fluorescence studies of these compounds revealed strong interaction with ct-DNA and bovine serum albumin (BSA).