Ultrasound-assisted synthesis of 4-thiazolidinone Schiff bases and their antioxidant, α-glucosidase, α-amylase inhibition, mode of inhibition and computational studies

Abstract

Diabetes mellitus (DM) has become a growing concern to global public health, being at the forefront of acute disorders and causes of mortality across the globe. Clinically approved drugs that are currently being used are faced with severe side effects, consequently necessitating the development of new drugs with no/fewer side effects and improved pharmacological potency. Herein, we report a rapid and efficient synthesis of thiazolidinone Schiff bases (2a-2t) from benzylidenehydrazines and thioglycolic acid under neat conditions through ultra-sonication. All the synthesized compounds were obtained in exceptional yields (89–95%) and confirmed by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, as well as High-resolution mass spectrometry (HRMS). The synthesized compounds were then evaluated for their antidiabetic activity through α-glucosidase and α-amylase inhibitory potentials and their antioxidant activity through Nitric Oxide (NO), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), and Ferric reducing antioxidant power (FRAP) assays. Among them, 2q (IC₅₀ = 96.63 μM) and 2h (IC₅₀ = 125.27 μM) emerged as the most potent derivatives against α-amylase relative to reference drug acarbose (IC₅₀ = 131.63 µM), respectively. Antioxidant evaluation further revealed that the synthesized derivatives were excellent NO scavengers disclosing 2n (IC₅₀ = 44.95 µM) as the most potent derivative. Moreover, in silico ADME calculations predicted these compounds to have excellent drug-like properties. Kinetic studies disclosed the mode of α-amylase inhibition as competitive while molecular docking studies of the most active derivatives performed into the binding active site of human pancreatic α-amylase enzyme deciphered their ligand-protein interactions that explicated their observed experimental potencies.