Template Synthesis, Characterization, Antioxidant Effects, DNA Cleavage and Antimicrobial Studies of ZnII, NiII, MnII, CuII and CoII Complexes Containing Pyridazinone Moiety

In this study, novel five Schiff base metal complexes derived from Zn II , Ni II , Mn II , Cu II and Co II metal salts and 5-benzoyl-4-hydroxy-2-methyl-6-phenyl-2H-pyridazine-3-one with o -aminophenol have been synthesized using a template method.  Metal complexes were characterized by elemental analysis, FT-IR, UV-Vis, Mass and magnetic susceptibility.  Antioxidant effects, DNA cleavage, and antimicrobial studies of synthesized compounds were performed. DPPH scavenging and metal chelating activity was found to increase with concentration. The highest DPPH activity and ferrous ion chelating activity were obtained from compound Zn. DNA cleavage studies indicated that all tested compounds were cleavage active at the concentration of 100 mg/L. While all the synthesized compounds displayed antibacterial activity against E. hirae in order of Mn>Zn=Ni=Co>Cu. The compound Ni only showed antimicrobial activity against all microorganisms tested, especially against L. pneumophila subsp. pneumophila with inhibition zone value equal to 13 mm.