Click synthesis of novel 6-((1H-1,2,3-triazol-4-yl)methyl)-6H-indolo[2,3-b]quinoxalines for in vitro anticancer evaluation and docking studies

Abstract

Herein, we report the design and synthesis of a novel series of 6-((1H-1,2,3-triazol-4-yl)methyl)-6H-indolo[2,3-b]quinoxalines (22–29) via the copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. The target compounds formed through two pathways (A and B). The structures of the newly click synthesised 1,2,3-triazole-6H-indolo[2,3-b]quinoxalines (22–29) were confirmed on the basis of their elemental analysis and spectral data. Some of these compounds exhibited significant antiproliferative effects against tested cancer cells, including hepatocellular carcinoma (Hep-G2), breast cancer (MCF-7), and colon cancer (HCT116), relative to healthy noncancerous control skin fibroblast cells (BJ-1) to evaluate their cytotoxic effects. Among the tested compounds, compound 27 exhibited strong activity with IC₅₀ = 9.3 ± 1.1, 1.5 ± 0.1, 2.4 ± 0.2, and 17.3 ± 1.2 against cancer cell lines HCT-116, HepG-2, MCF-7, and BJ-1, respectively. Therefore, compound 27 was selected for further investigation. Cell cycle analysis of liver cancer (HepG-2) cells treated with 27 showed cell cycle arrest in the S and G0/G1 phases and strong apoptotic activity, as indicated by Annexin V-FITC staining. Compound 27 was also found to fit in the ATP binding pocket during docking experiments combined with molecular dynamics simulation. Lastly, we conducted a Petra/Osiris/Molinspiration (POM) study on the synthesized compound. The most promising candidates were identified by evaluating primary in silico parameters, which showed considerable differences among individual synthesized compounds. These features can promote future drug candidate design to produce better derivatives in the search for anticancer agents, particularly those with favorable ADME parameters, low toxicity, anticipated bioactivity, and bright futures.