Novel Spiro/non-Spiro Pyranopyrazoles: Eco-Friendly Synthesis, In-vitro Anticancer Activity, DNA Binding, and In-silico Docking Studies

Abstract

Cancer being a deadly disease, many reports of new chemical entities are available. Pyranopyrazole (PPZ) compounds have also been disclosed as bioactive molecules but mainly as antimicrobial agents. Based on one previous report and our interest in anticancer drug design, we decided to explore PPZs as anticancer agents. To the best of our knowledge, we found that a comprehensive study, involving synthesis, in-vitro biological activity determination, exploration of the mechanism of inhibition and finally in-silico docking studies, was missing in earlier reports. This is what the present study intends to accomplish.

Methods: Ten spiro and eleven non-spiro PPZ molecules were synthesized by environment-friendly multicomponent reaction (MCR) strategy. After subjecting each of the newly synthesized molecules to Hep3b hepatocellular carcinoma cell lines assay, we selectively measured the Optical Density (OD) of the most active ones. Then, the compound exhibiting the best activity was docked against human CHK- 1 protein to get an insight into the binding affinities and a quick structure activity relationship (SAR) of the PPZs.

Results: The two series of spiro and non-spiro PPZs were easily synthesized in high yields using microwave assisted synthesis and other methods. Among the synthesized compounds, most compounds showed moderate to good anticancer activity against the MTT assay. After performing the absorbance studies we found that the non-spiro molecules showed better apoptosis results and appeared to bind to DNA causing disruption in their structures. Finally, the docking results of compound 5h (having N,Ndimethylamino substituted moiety) clearly showed good binding affinities as predicted by our experimental finding