Antilipase and antioxidant activities of topiramate-phenolic acid conjugates: Computational modelling, synthesis, and in-vitro investigations

A series of ten topiramate-phenolic acid conjugates (T1-T10) were synthesized, and evaluated for their pancreatic lipase inhibitory and antioxidant potentials. The design of the compounds reflected the structural attributes extracted from robust QSAR models developed for predicting the pancreatic lipase inhibition potency. Conjugate T4 competitively inhibited pancreatic lipase with IC₅₀ value of 8.96 μM, comparable to the standard drug, orlistat (IC₅₀ = 11.68 μM). Molecular docking of T4 into the active site of human PL (PDB ID: 1LPB) revealed strong binding score of -11.54 kcal/mol. Molecular dynamics simulation of T4 complexed with pancreatic lipase, confirmed the role of phenolic acid core in stabilizing the ligand through hydrophobic interactions (maximum observed RMSD = 3.77 Å). Additionally, T4 with its LUMO (-0.20254) and HOMO (0.30502) values, abstracted from DFT studies, depicts considerable promise in the pursuit of selecting an effective enzyme inhibitor binding to the enzyme's active site and disrupting its catalytic function. The conjugation of topiramate with phenolic acids has imparted potential antioxidant properties to the synthesized conjugates especially T3, T4 and T5. Conclusively, with good safety profile as predicted from in silico ADMET studies, potent pancreatic lipase inhibition and free radical quenching, T4 stands taller as promising anti-obesity drug candidate.