Development of Pyrimidine-2,4-Dichlorophenyl Conjugates as Xanthine Oxidase Antagonists for Gout Therapy: Computational and Experimental Study

A novel group of pyrimidine-based hybrids containing a 2,4-dichlorophenyl core was designed, synthesized, and evaluated as potential xanthine oxidase (XO) inhibitors for treating gouty arthritis. Through established medicinal chemistry synthetic methods, these compounds were successfully prepared and their structures confirmed using detailed spectroscopic analyses, including high-resolution mass spectrometry (HRMS), Fourier-transform infrared (FT-IR), and multinuclear NMR (¹H and ¹³C). In vitro screening, nine candidates (2, 3, 9, 10, 11a, 11d, 11e, 12a, and 12b) assessed their XO inhibitory activity, ability to prevent protein denaturation, and capability to stabilize erythrocyte membranes. Notably, compound 12b emerged as the most promising agent, displaying superior XO inhibition (IC₅₀ = 2.8 μM), effective protein denaturation suppression (89.4% at 100 μg/mL), and significant reduction in hemolysis (92.1% efficacy), surpassing standard drugs like allopurinol and diclofenac. Molecular docking simulations indicated strong binding between the compounds and the XO active site, with 12b showing optimal interactions through hydrogen bonding and hydrophobic contacts. These computational results were consistent with experimental outcomes, suggesting a mechanism of competitive inhibition. The overall findings highlight the therapeutic potential of 12b as a leading candidate for gout management, providing a foundation for further optimization in developing advanced XO inhibitors with improved efficacy and selectivity.