Rational design of phenyl 2,4,5-trichlorobenzenesulfonate based thiosemicarbazones as α-glucosidase and α-amylase inhibitors: integrating enzymatic evaluation and molecular modeling

Abstract

The present study aimed to investigate the antidiabetic potential of a new series of thiosemicarbazone derivatives through integrated in vitro enzymatic assays and in silico molecular modeling. The synthesized compounds were evaluated for their inhibitory activities against α-glucosidase (α-Glu) and α-amylase (α-Amy) enzymes. Among the tested derivatives, compound 16 (2-chlorophenyl-substituted) demonstrated the most potent dual inhibition with IC₅₀ values of 14.58 nM (α-Glu) and 88.37 nM (α-Amy), surpassing the reference drug acarbose in potency. Molecular docking analyses revealed that compound 16 formed stable interactions with Asn-214, Glu-276, Phe-157, and Tyr-71 in the α-Glu and Asp-197, Glu-233, and Lys-200 in α-Amy's active site. These key interactions were further supported by 250 ns molecular dynamics simulations, confirming the conformational stability of both complexes with average RMSD values below 2.0 Å and minimal ligand fluctuations. Energy decomposition analysis indicated that van der Waals and electrostatic interactions were the major contributors to the overall binding free energy. In silico ADME profiling predicted favorable pharmacokinetic properties, including high gastrointestinal absorption, good oral bioavailability, and compliance with Lipinski's rule of five, while no significant blood–brain barrier penetration was observed. The combined in vitro and in silico findings highlight compound 16 as a promising lead candidate for further optimization and development as a dual α-Glu and α-Amy inhibitor for the management of type 2 diabetes mellitus.