Synthesis, characterization, thermal study, and evaluation of mixed ligand complexes of (malonic acid, nicotinic acid, and 2-aminopyridine) with some transition metal ions

Abstract

Six mixed ligand complexes were prepared from malonic acid (MA), nicotinic acid (NA), and 2-aminopyridine (AP) in a (1:1:1:1) molar ratio (M: MA: NA: AP.), using aqueous ethanol as a reaction medium. The prepared compounds were analyzed by flame atomic absorption, (C.H.N.) analysis, and FTIR, UV-Vis, and mass spectroscopy, as well as conductivity measurement and magnetic susceptibility studies. Based on the combined analytical data, the prepared complexes were proposed to adopt an octahedral geometry.   A urinary tract infection (UTI) is a bacterial infection that affects any part of the urinary tract.   The emergence of antibiotic-resistant bacteria and fungi has led to poor patient outcomes and limited treatment options, prompting interest in mixed ligand-metal complexes as potential antimicrobial agents.  Accordingly, this study evaluated the inhibitory activity and effectiveness of the free ligands, metal complexes, and DMSO (as a control) at a concentration of 10^-3 mg/mL against clinically isolated UTI (S. aureus, S. epidermidis, E. coli, K. pneumoniae, and C. albicans). The results demonstrated that both the ligands and complexes exhibited varying degrees of activity against the tested.

KEY WORDS: Malonic acid (MA), Nicotinic acid (NA), 2-Aminopyridine (AP), Metal complexes, Spectral analysis, Biological activity

Bull. Chem. Soc. Ethiop. 2026, 40(10), 2131-2143.                                         

DOI: https://dx.doi.org/10.4314/bcse.v40i10.6