Carprofen: a theoretical mechanistic study to investigate the impact of hydrophobic interactions of alkyl groups on modulation of COX-1/2 binding selectivity

Abstract

Development of selective COX-1 and COX-2 was successfully used to overcome GIT side effects of the classical NSAIDs. Currently, virtual screening and docking study were extensively used to design of new potent and safe drug candidates. In this study, four series of carprofen derivatives were designed by isosteric replacement of the –NH– with –O–, –S– and –CH2– groups. More than 90 derivatives bearing different alkyl substituents were designed in this study. AutoDock software was used to explore the binding mode, affinity and selectivity of the designed analogs to COX1/2. The results revealed that position and length of alkyl substituents have remarkable effect on the binding mode. Substitution with alkyl groups at C1 and C6 of the four scaffolds improved binding to COX-1, while at C4 enhanced COX-2 binding affinity. Compound 66 displayed the highest binding affinity for COX-1 and COX-2 with ΔGb of 11.2 and 10.15 kcal/mol, respectively. Compound 56 and 99 displayed the highest potential selectivity to COX-1 and COX-2, respectively. Drug-likeness study and synthetic accessibility were evaluated for the most promising analogs. Compound 29 displayed drug-likeness score (DLS) of 0.96 compared to 0.3 for carprofen. Taken together, these results highlighted the importance of hydrophobic interactions in modulation of COX-1/2 binding selectivity of new potential NSAIDs.