Synthesis, Characterization and Antibacterial Activity of Some New Neocuproine Schiff Bases

Abstract

Background and Objectives: Schiff base ligands are prepared via the condensation reaction of 1, 10-dimethyl-phenantroline aldehyde derivative with some nitrogen donor ligands, such as benzene ring that have different functional groups (-OH,-SH,-OCH3,-CH2OH,-Br) in acetonitrile. Recent studies suggest that Schiff bases might have antibacterial activity. Therefore, we aimed to synthesize new Schiff base complexes and evaluate their antibacterial activity against a number of Gram-positive and Gram-negative bacteria. Methods: Schiff base ligands and their complexes were characterized by mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy. The in vitro antibacterial activity of the Schiff base ligands and metal ions against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the broth dilution method. Results: All synthesized Schiff bases exhibited favorable antibacterial activity against the tested microorganism, but the antibacterial effect of compounds 3OH and 3SH was more significant than that of other compounds. Conclusion: Compound 3EOH has favorable antibacterial activity against the tested bacteria.