Mining of potential dipeptidyl peptidase-IV inhibitors as anti-diabetic agents using integrated in silico approaches

Pyrazoline scaffold: hit identification to lead synthesis and biological evaluation as antidiabetic agents

Background: Mining of novel scaffolds as potential DPP-IV inhibitors for future development of potential candidates as antidiabetic agents to address global issues. Methodology: The identified hit KB-10 from a previously reported study was taken as a lead for designing a library of analogues and screened initially based on in silico parameters and docking score. A series of selected (2[4-(1-acetyl-5-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenoxy]-1-phenylethanone derivatives were synthesized and evaluated through in vitro studies. Compounds KB-23, KB-22 and KB-06 were found to be as potent, with IC₅₀ values of 0.10 μM, 0.12 μM and 0.35 μM, respectively. They also showed promising antihyperglycemic potential in in vivo studies (oral glucose tolerance tests) in Wistar rats. Conclusion: This work establishes pyrazoline analogues KB-23, KB-22 and KB-06 as promising starting points for the development of potential antidiabetic agents.

Discovery, synthesis and in combo studies of Schiff's bases as promising dipeptidyl peptidase-IV inhibitors

Diabetes mellitus is a main global health apprehension. Macrovascular illnesses, neuropathy, retinopathy, and nephropathy are considered some of its severe hitches. Gliptins are a group of hypoglycemic agents that inhibit dipeptidyl peptidase-IV (DPP-IV) enzyme and support blood glucose-lowering effect of incretins. In the current research, synthesis, characterization, docking, and biological evaluation of fourteen Schiff's bases 5a-f and 9a-h were carried out. Compound 9f revealed the best in vitro anti-DPP-IV activity of 35.7% inhibition at a concentration of 100 μM. Compounds 9c and 9f with the highest in vitro DPP-IV inhibition were subjected to the in vivo glucose-lowering test using vildagliptin as a positive inhibitor. Vildagliptin, 9c, and 9f showed significant reduction in the blood glucose levels of the treated mice after 30 min of glucose administration. Moreover, induced fit docking showed that these derivatives accommodated the enzyme binding site with comparable docking scores. Schiff's bases can serve as promising lead for the development of new DPP-IV inhibitors.

In silico strategies for probing novel DPP-IV inhibitors as anti-diabetic agents

Identification of new DPP-IV inhibitors by integrating validated in silico approach is being presented herein. Novel hits were identified by combining pharmacophore and structure based virtual screening of ZINC and Knowledge Base in house database followed by ADME profiling, consensus docking studies. Six potential hits were identified and analysed for their synthetic accessibility score, novelty analysis and pan assay interference compounds filtration. Out of six, three hits viz., ZINC25060187, ZINC53746227 and KB-10 were analysed for stability studies using Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) and Molecular Dynamics (MD) simulation. The simulation studies of the identified hits revealed that these hits have good selectivity and stability in DPP-IV binding pocket. Important interactions with amino acids viz., Tyr547, Glu205 and Glu206 similar to co-crystallized ligand were also observed. One of the hits viz., KB-10 was synthesized and evaluated for its biological potential. The compound KB-10 showed good DPP-IV inhibition in both in vitro and in vivo studies with IC₅₀: 22.69 µM. This study supports the fact that these techniques hold potential for efficient screening of compounds with unknown affinity for DPP-IV that could serve as candidates for therapeutic development.Communicated by Ramaswamy H. Sarma.