New Hybrid Hydrazinyl Thiazole Substituted Chromones: As Potential α-Amylase Inhibitors and Radical (DPPH & ABTS) Scavengers

Current research is based on the identification of novel inhibitors of α -amylase enzyme. For that purpose, new hybrid molecules of hydrazinyl thiazole substituted chromones 5 – 27 were synthesized by multi-step reaction and fully characterized by various spectroscopic techniques such as EI-MS, HREI-MS, 1 H-NMR and 13 C-NMR. Stereochemistry of the iminic bond was confirmed by NOESY analysis of a representative molecule. All compounds 5–27 along with their intervening intermediates 1–4 , were screened for in vitro α -amylase inhibitory, DPPH and ABTS radical scavenging activities. All compounds showed good inhibition potential in the range of IC 50 = 2.186–3.405 µ M as compared to standard acarbose having IC 50 value of 1.9 ± 0.07 µ M. It is worth mentioning that compounds were also demonstrated good DPPH (IC 50 = 0.09–2.233 µ M) and ABTS (IC 50 = 0.584–3.738 µ M) radical scavenging activities as compared to standard ascorbic acid having IC 50 = 0.33 ± 0.18 µ M for DPPH and IC 50 = 0.53 ± 0.3 µ M for ABTS radical scavenging activities. In addition to that cytotoxicity of the compounds were checked on NIH-3T3 mouse fibroblast cell line and found to be non-toxic. In silico studies were performed to rationalize the binding mode of compounds (ligands) with the active site of α -amylase enzyme.