Preparation and Characterization of Curcumin Complexes with Zinc(II), Nickel(II), Magnesium(II), Copper(II) and their Evaluation Against Gram-positive and Gram-negative Bacteria

Angulo-Cornejo J.; Delgado-Villanueva J. · Revista Politecnica (2023) · DOI: 10.33333/rp.vol51n2.06

Resumen

Copper(II), zinc(II), nickel(II) and magnesium(II) complexes have been prepared with the ligand curcuminate, in a molar ratio of 2:1 ligand:metal, in ethanol as solvent: [M(curcumin)2] (M = Ni2+, Cu2+, Mg2+ and Zn2+). Job's spectrophotometric method (method of continuous variations) was used to determine the stoichiometric Ligand-Metal ratio (2:1). A number of techniques were used to characterize the complexes, including elemental analysis, mass spectrometry, infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (1H-NMR, 13C-NMR). Each curcuminate binds to the metal through two oxygen atoms (C=O and C-O-), forming six-membered chelate rings. The results of the antibacterial study of the complexes prepared against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative), by means of the Kirby-Bauer method (agar diffusion method), indicate that all of the complexes present significant antibacterial activity against Staphylococcus aureus, particularly the curcumin-zinc complex, which has significant antibacterial activity against Staphylococcus aureus even at low concentrations.

Instituciones: Universidad Nacional Mayor de San Marcos