Structural elucidation and computational studies of novel bidentate organometallic complexes of 2-thiophene carboxylic acid with ethyl-2-amino acetate for antidiabetic applications

Abstract

In this study, novel Schiff base ligands and their Cu(II), Co(II), and Ni(II) metal complexes were synthesized and characterized using spectroscopic techniques, including FT-IR, UV-visible, NMR, and mass spectrometry. The synthesis involved a multi-step reaction starting from thiophene carboxylic acid and ethyl-2-aminoacetate to form N-(2-oxo-2-(phenylamino)ethyl)thiophene-2-carboxamide. The resulting compounds were then complexed with metal salts, yielding stable metal complexes. Structural analysis confirmed coordination through azomethine nitrogen and thiophene oxygen atoms. Computational studies, including molecular docking, revealed strong binding interactions between the ligand, its complexes, and the α-amylase enzyme, highlighting their potential antidiabetic activity. The Cu(II) complex exhibited the highest binding energy (–321.3 kJ/mol) and optimal hydrogen bonding interactions. Density functional theory (DFT) calculations further supported the stability and electronic properties of the ligand and complexes. Biological studies demonstrated significant α-amylase inhibition, with the Cu(II) complex showing superior activity compared to standard drugs. These findings suggest that Schiff base-metal complexes could serve as promising antidiabetic agents.