New Pyranopyrazole-Based Indolin-2,3-dione Hybrid as Effective Inhibitors of Xanthine Oxidase: Synthesis, In Vitro, and Molecular Modelling Approaches

In the current study, new pyranopyrazole analogues (9a-d and 10a-d) were synthesized through a one-pot condensation reaction of 2-arylacetohydrazide. The inhibitory abilities were investigated against the XO enzyme through experimental and molecular docking analyses. The synthesis studies were based on ultrasound-mediated condensation reactions of four-component systems containing 2-arylacetohydrazide, ethyl acetoacetate, indoline-2,3-dione, and ethyl 2-cyanoacetate/malononitrile in various solvents and catalysts to yield pyranopyrazole analogues (9a-d and 10a-d) in a short reaction time and remarkably favorable yields ranging from 79-92%. Based on the XO inhibition study of compounds 9a-d and 10a-d, compound 10d was the most potent (IC50 = 0.09 ± 0.22 µM), followed by 9c (0.12 ± 0.11 µM). With IC50 values of 0.20 ± 0.27 µM and 0.17 ± 0.11 µM respectively, compounds 10a and 10c exhibited moderate activity. The other compounds have shown less activity compared to the allopurinol control (IC50 = 0.14 ± 0.10 µM). Furthermore, in the molecular docking analysis, compound 10d was predicted to have the highest binding affinity against the target XO enzyme.