Synthesis, characterization, and antimicrobial activity of metal complexes derived from Schiff base of quercetin extracted from Origanum vulgare L.

Abstract

Origanum vulgare L. is a rich source of phenolic compounds, among which quercetin exhibits remarkable antioxidant properties capable of scavenging free radicals. In this study, we synthesized a Schiff base by combining quercetin extracted from Origanum vulgare L. with ethanolamine. The Schiff base was then used as a precursor for the synthesis of five novel metal complexes comprising Cu(II), Ni(II), Zn(II), Fe(II), and Co(II) ions. The structures of both the ligand and the metal complexes were characterized using a diverse range of analytical techniques, including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), elemental analysis, molar conductivity, proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR), and energy-dispersive X-ray analysis (EDX). The antimicrobial activity of the synthesized metal complexes against Escherichia coli and Pseudomonas aeruginosa bacteria and Candida albicans fungi was evaluated. The results demonstrate that the synthesized metal complexes exhibit promising antimicrobial activity, highlighting their potential as therapeutic agents.