Molecular insights into benzene sulphonamide substituted diarylpyrazoles as cyclooxygenase-2 inhibitor and its structural modifications.

Quantitative Structure Activity Relationship (QSAR) is one of the realistic and most successful methods for drug design in optimizing a lead. A series of forty-four molecules from diarylpyrazole benzene sulphonamide derivatives with their cyclooxygenase-2 inhibitory activity were subjected to qsar studies using QSARINS software. The significant two descriptor qsar model generated showed correlation coefficient of cross validation leave one out (Q)=0.5565, coefficient of determination (R)=0.6530, (R)=0.8225, cross validation leave many out (Q2)=0.5201, Concordance Correlation Coefficient (CCC)=0.7262, CCC=0.7901, and CCC=0.8930. The descriptor 3D Molecular Representations of Structures based on Electronic diffraction (3D-MoRSEC-6) weighted by atomic charges, where 6 is scattering parameter and Geary Autocorrelation-lag3/weighted by atomic Sanderson electronegativities (GATSe3) revealed that the atomic charges and spatial autocorrelation play a key role in Cyclooxygenase-2 inhibitory (COX-2) activity. New lead molecules were designed based on key structural findings and predicted for their COX-2 inhibitory activity using the developed two-descriptor model. Molecular docking studies were carried out for the best-designed molecules using Autodock 4.2.6 along with supportive absorption, distribution, metabolism, excretion, and toxicity predictions. Both the hydrophilic as well as hydrophobic parts of the residues of active site regions interacted with best predicted active compounds. The study suggests crucial properties and key interactions that are essential for potent enzyme inhibition and finds this series as a promising lead for further development as novel cyclooxygenase agents. Communicated by Ramaswamy H. Sarma.