Synthesis, characterization and antibacterial activity of Ni (II) and Mn (II) cephalexin complexes

The increasing threat of antimicrobial resistance has necessitated the development of novel therapeutic strategies. This study focuses on the synthesis, characterization, and antimicrobial evaluation of divalent metal-cephalexin complexes involving Mn (II) and Ni (II). Cephalexin, a β-lactam antibiotic, was coordinated with these metal ions to enhance its stability and bioactivity. The complexes were synthesized through a reflux method and characterized using solubility tests, decomposition temperature analysis, Fourier Transform Infrared (FT-IR) spectroscopy, conductivity measurements, magnetic susceptibility, and Job’s method of continuous variation. The results indicate that the metal complexes exhibit tetrahedral geometry and are non-electrolytic in nature. Antimicrobial screening against selected bacterial and fungal strains, including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans, Tinea capitis, and Tinea pedis, demonstrated that the metal complexes retained antimicrobial activity, albeit lower than free cephalexin. The findings suggest that while metal complexation influences drug stability and coordination chemistry, further studies are needed to optimize their therapeutic efficiency.