IN SILICO MOLECULAR DOCKING OF XANTHONE DERIVATIVES AS CYCLOOXYGENASE-2 INHIBITOR AGENTS

Abstract

Objective: To demonstrate the potential ofdifferent xanthone derivatives as cyclooxygenase-2 (COX-2) inhibitor agents and their selectivity against cycloooxygenase-1 (COX-1) and COX-2 using molecular simulation.Methods: Nine novel xanthone derivatives (compounds A-I) were employed to dock against protein COX-2 (Protein Data Bank/PDB ID: 1CX2) and COX-1 (PDB ID: 3N8Z). Celecoxib, a selective COX-2 inhibitor, was chosen as a control compound. The free binding energy produced by the docking was scored using Protein-Ligand Ant System (PLANTS) and the hydrogen bonds (H-bonds) between ligands and enzymes were visualised using Pymol.Results: Molecular docking studies revealed that celecoxib docked to the active site of COX-2 enzyme, but not to COX-1; whereasxanthone derivatives docked to the active site of both COX-2 and COX-1. Free binding energy of xanthone derivatives ranged between-73,57 to-79,18 and between-73,06 to-79,25 against COX-2 and COX-1, respectively, and-78,13 against celecoxib. H-bonds in the molecule of xanthone derivatives and COX-2 protein were found in amino acid residues Arg120, Tyr355, Tyr385,and Ser353. There was an insignificant difference between the free binding energyof xanthone derivatives against COX-2 and against COX-1, suggesting that their inhibition was non-selective.Conclusion: In conclusion, in silico studies showed that xanthone derivatives could be effective as potential inhibitors against COX-2, although they are not selective.