Dipeptidyl peptidase-4 DPP-4 inhibition has remained one of the most established ways in treating type 2 diabetes mellitus. Therefore, the development of improved DPP-4 inhibiters is consideredan essential strategy in the design of antidiabetic drugs. In the present study, a structure-based virtual approach was considered to design and evaluate new sitagliptin analogues with improved binding stability and pharmacokinetic properties. A virtual library consisting of 15,034 different compounds was created and then screened using a hierarchical Glide docking protocol (HTVS, SP, and XP). Using integrated computational analyses, the top ranked compounds were further assessed. Based on ADMET predictions, MM-GBSA binding free energy calculations, the results revealed that out of all the screened compounds, only 28 candidates had better docking scores than sitagliptin and compounds 14 and 22 were the most promising screened analogues. Compared to other tested analogies, compound 14 showed stable binding profile,low MM-GBSA binding free energy,stable ionic interactions between the catalytic residues Glu205 and Glu206, stable hydrophobic interactions within the S1 pocket. In addition, based on ADME simulation, compound 14 presented acceptable drug-like properties which indicates good oral bioavailability and lower predicted CNS penetration compared to sitagliptin. Overall, further experimental validation and development is required to evaluate compound 14 which exhibitsan increased electrostatic complementarity, dynamically stable properties, and acceptable pharmacokinetic properties making it a promising candidate as a DPP-4 inhibitor.
