A study of in vitro antimicrobial activities and antioxidant of lanthanide complexes with a tri dentate Schiff base ligand

Abstract

The tridentate N3-type Schiff base 4-(anthracen-10-yl)-2,6-di(pyridin-2-yl)pyridine was synthesized from the condensation reaction of 2-acetyl pyridine and anthracene-10-carbaldehyde with ammonia using one pot methodology. This hybrid ligand was used for synthesis of lanthanide complexes (La, Sm and Eu) as novel potential biological agent. The lanthanide complexes were characterized on the basis of elemental, FT-IR, UV-Visible, mass spectrometry as well as molar conductivity. The complexes were screened for in vitro antibacterial and antifungal activities against the multidrug resistant pathogens such as Escherichia coli, Staphylococcus aureus and Aspergillus niger. The antimicrobial results revealed that Sm+3 complex has a good potency against different gram positive and gram negative bacteria in comparison with other complexes. All lanthanide complexes showed a moderate antioxidant activity with IC50. The DPPH· radical scavenging effects of the Schiff base ligand and its Ln (III) complexes were screened. The Ln (III) complexes were significantly more efficient in quenching DPPH· than the free Schiff base ligand.