Complexation of alkaline earth metals Mg2+, Ca2+, Sr2+ and Ba2+ with adrenaline hormone: Synthesis, spectroscopic and antimicrobial analysis

Abstract

ABSTRACT. Adrenaline complexes with bivalent ions Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺ in methanol at 60 ^oC were prepared. The prepared complexes were isolated and characterized using elemental analyses, conductivity measurements, mid infrared, Raman laser, UV-Vis., ¹H–NMR spectra, X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). Upon the spectroscopic, conductivity and elemental analyses, the stoichiometric reactions indicated 1:2 (M:L) for Ca²⁺, Sr²⁺ and Ba²⁺ complexes [Ca(Adr)₂(H₂O)₂](H₂O)₄Cl₂, [Sr(Adr)₂(H₂O)₂]Cl₂ and [Ba(Adr)₂(H₂O)₆]Cl₂ while the molar ratio of 1:1 (M:L) for Mg²⁺ with a formula [Mg₂(Adr)₂(H₂O)₇]Cl₄. The interpretation of Raman and infrared spectra confirmed the coordination mode, which was through the two-catechol moiety OH phenolic groups. The in vitro antibacterial activity of adrenaline chelates that have been tested against three gram-positive bacteria, two gram-negative bacteria, and two strains of fungus showed that antimicrobial activity of the metal chelates are more effective than the adrenaline free ligand.

KEY WORDS: Adrenaline, heavy metals, infrared, biological outcomes

Bull. Chem. Soc. Ethiop. 2023, 37(2), 357-372.                                                               

DOI: https://dx.doi.org/10.4314/bcse.v37i2.9