3-Phenoxybenzaldehyde and Glycine-Derived Schiff base M(II) Complexes: Synthesis, molecular Modeling, spectroscopic Exploration, and antimicrobial evaluation

Abstract

This study synthesized a novel bidentate Schiff base known as 2-((3-phenoxybenzylidene)amino)acetic acid (HL) derived from glycine and 3-phenoxy benzaldehyde and its M(II) complexes (M = Co2+, Cu2+, Ni2+ & Zn2+) was prepared by combining the Schiff base (HL) and the metal acetates in a 1:2 ratio. The molecular structure of the Schiff base was confirmed using CHN analysis, mass, FT-IR, UV–Vis, 1H NMR and 13C NMR spectra. The prepared complexes were analyzed using CHN analysis, mass, FT-IR, UV–Vis, molar conductivity studies, magnetic susceptibility studies, and ESR for Cu(II) complexes. Based on the analysis, square planar geometry is suggested for the Cu(II) & Ni(II) complexes and tetrahedral geometry for Co(II) and Zn(II) complexes. A preliminary in vitro antimicrobial investigation of the synthesized ligand and its related complexes has been performed. The M(II) complexes showed more potent antimicrobial activity than its Schiff base; in particular, the Cu(II) complex illustrated notable inhibitory effects. Molecular docking studies were conducted against CDK2 (PDB ID: 1B39), α-amylase (PDB ID: 4W93), and α-glucosidase (PDB ID: 3TOP). The Ligand HL demonstrated AutoDock/MM-GBSA binding energy values of −5.9 /-104 kcal mol−1 (CDK2), −6.6 /-134 kcal mol−1 (α-amylase), and −7.4/ −174.84 kcal mol−1 (α-glucosidase). The complexes exhibited MM-GBSA binding energy values within the range of −198.20 to −198.72 kcal mol−1 (CDK2), −250.00 to −250.02 kcal mol−1 (α-amylase), and −279.51 to −283.84 kcal mol−1 (α-glucosidase). The molecular docking results shed light on the potential of ligand HL and its metal complexes as promising candidates for further exploration in therapeutics, particularly in targeting CDK2 inhibition (anticancer) and α-amylase and α-glucosidase inhibition (antidiabetic).