N‑Alkylated 5,5-Diphenylhydantoin Derivatives: Synthesis, X‑ray, Spectroscopic Characterization, Hirshfeld Surface...

This study presents the synthesis and characterization of nine N-alkylated phenytoin derivatives 4-13. These compounds were synthesized and characterized using spectroscopic techniques including ¹³C and ¹H nuclear magnetic resonance spectroscopy, UV-visible spectroscopy, infrared spectroscopy, and liquid chromatography-mass spectrometry. The structures of 4-6 were confirmed by X-ray crystallography. The geometrical parameters and spectral data were also compared with those of a density functional theory geometry optimization and molecular orbital calculation at the B3LYP/6-311++G-(d,p) level of theory. Hirshfeld surface analysis indicated that hydrogen-hydrogen interactions (56-62%) predominated in the crystal arrangement. Molecular docking studies demonstrated strong binding affinities with cholesterol oxidase, with compound 4 exhibiting the highest affinity at -10.97 kcal/mol, outperforming compounds 5 (-8.94 kcal/mol) and 6 (-9.66 kcal/mol). The stability of the compound 4-cholesterol oxidase complex, with a protein root-mean-square deviation of 1.24 ± 0.07 Å, was confirmed through an 80 ns molecular dynamics simulation. Moreover, molecular mechanics-generalized Born surface area (MM-GBSA) calculations estimated a total binding free energy of -51.5 ± 10.6 kcal/mol, with significant contributions from van der Waals and electrostatic interactions. These findings suggest that compound 4 is a promising inhibitor of cholesterol oxidase, providing valuable insights for pharmaceutical development.