Synthesis of novel 5-[(1,2,3-triazol-4-yl)methyl]-1-methyl-3H-pyridazino[4,5-b]indol-4-one derivatives by click reaction and exploration of their anticancer activity

Abstract

A series of pyridazino[4,5-b]indole derivatives containing alkyl-, benzyl- and phenacyl-substituted 1,2,3-triazolylmethyl units was synthesized using click chemistry approach. All 30 compounds of the series were screened in vitro against four cancer cell lines, viz. breast cancer cells MDA-MB-231 and MCF 7, human primary glioblastoma U-87 and human neuroblastoma IMR-32 cell lines. Most of the compounds exhibited potent cancer cell growth inhibition activity at very low micromolar concentrations. The IC50 value of compounds 7v and 7x against human neuroblastoma IMR-32 cell line is 0.07 and 0.04 µM, respectively. Among the tested compounds, ten compounds showed IC50 value less than 1 µM against MDA-MB-231 cells, whereas against IMR-32 cells, nine compounds and, against U-87 cells, six compounds showed similar inhibition activity. Further, these molecules exhibited prominent binding affinity and docking scores in the molecular simulation study with the target enzyme PI3 kinase. This paper illustrates the synthesis of new fused indole–pyridazinone derivatives containing substituted 1,2,3-triazoles via click chemistry approach. Most of the compounds exhibited potent cancer cell growth inhibition activity at very low micromolar concentrations.