Amberlite IR-120H Catalyzed Synthesis of 1,3-Diphenylpyrazolechromenoquinolin-6-one Compounds and Their Biological Evaluation

A series of 1,3-diphenylpyrazole-chromenoquinolin-6-one compounds were designed and synthesized by using a greener and recyclable heterogeneous Amberlite IR-120H resin as a catalyst, in the presence of ethanol reflux conditions. Interestingly, the catalyst can be recovered after completion of the reaction and can be reused without loss of catalytic property. Therefore, this method provides a green and environmentally benign much improved protocol for the synthesis of 1,3-diphenylpyrazolechromenoquinolin-6-one compounds. The synthesized library of thirty compounds were tested against their cytotoxicity; moreover, the compounds 5s and 5t exhibited potential cytotoxic activity with IC50 values of 1.22 and 1.64 µM, respectively, on MCF-7 cancer cells. The biophysical studies such as UV-visible, fluorescence and circular dichroism studies indicate that these compounds possess good DNA intercalation ability. In addition, these compounds efficiently inhibit topoisomerase I activity. Molecular docking and viscosity studies support that these compounds exhibited intercalative mode of binding with DNA.