Cobalt(II) and Nickel(II) Complexes of a Schiff Base Derived from N-Benzylisatin and p-Anisidine: Synthesis, Characterization, DFT Analysis, Molecular Docking, and Antidiabetic Evaluation

Abstract

New cobalt(II) and nickel(II) complexes derived from a 1-benzyl-3-[(4-methoxyphenyl)imino]indolin ligand were synthesized and characterized through various spectroscopic and analytical methods. In-silico ADMET profiling was performed to evaluate their pharmacological potential, and quantum chemical calculations employing density functional theory with the B3LYP functional and the 6-311+G basis set were conducted. Molecular docking against α-glucosidase and in vitro assays against α-amylase and α-glucosidase enzymes were used to assess their antidiabetic activity. Spectroscopic data revealed the ligand acts as a bidentate chelator. The Ni(II) complex is predicted to have an octahedral geometry, and the Co(II) complex a tetrahedral structure. In vitro results showed moderate to strong inhibitory activity against both enzymes, with the Ni(II) complex showing significant α-amylase inhibition and the Co(II) complex showing significant α-glucosidase inhibition. ADMET analysis indicated safety for all compounds. The Ni(II) complex demonstrated a binding energy of −50.3749 kcal/mol, and the Co(II) complex −9.3653 kcal/mol, suggesting these metal complexes are potential antidiabetic therapeutic agents.