Receptor and ligand-based 3D-QSAR study on a series of nonsteroidal anti-inflammatory drugs
Comparative molecular field analysis and comparative molecular similarity indices analysis were performed on 114 analogues of 1,2-diarylimidazole to optimize their cyclooxygenase-2 (COX-2) selective antiinflammatory activities. These studies produced models with high correlation coefficients and good predictive abilities. Docking studies were also carried out wherein these analogues were docked into the active sites of both COX-1 and COX-2 to analyze the receptor ligand interactions that confer selectivity for COX-2. The most active molecule in the series (53) adopts an orientation similar to that of SC-558 (4-[5-(4-bromophenyl)-3-trifluoromethyl-1H-1-pyrozolyl]-1-benzenesulfonamide) inside the COX-2 active site while the least active molecule (101) optimizes in a different orientation. In the active site, there are some strong hydrogen-bonding interactions observed between residues His90, Arg513, and Phe518 and the ligands. Additionally, a correlation of the quantitative structure-activity relationship data and the docking results is found to validate each other and suggests the importance of the binding step in overall drug action.