DNA cleavage efficiency of transition metal(II) Schiff base complexes of 4-aminoantipyrine derivative : Synthesis, characterization and antimicrobial study

A new bidentate Schiff base ligand derived from 4-aminoantipyrine and o-acetoacetotoluidide and its Cu(II), Co(II), Ni(II) and Zn(II) metal complexes have been synthesized and characterized by microanalytical data, IR, UV-Vis, (1)H NMR and mass spectra. The conductance measurements indicate that all the complexes are electrolytes. The IR spectra indicate the coordination of azomethine nitrogen atom of the Schiff base and cyclic carbonyl group of the pyrazolone ring. The UV-Vis spectral-data demonstrate that the complexes have square-planar geometry. The FAB mass spectra confirm-the composition of the complexes of the type ML(2) where M = Cu(II), Co(II), Ni(II) and Zn(II). Their magnetic susceptibility values provide evidence for the monomeric nature. The gel electrophoresis experiment has been carried out on the interaction of the complexes with CT-DNA. The-nuclease activity of the above metal complexes shows that only the copper complex cleaves DNA in the presence of oxidant. Antimicrobial activities of the compounds are tested in vitro against four bacteria and three fungi by the disc diffusion method. The MIC value against the growth of microorganisms is much larger for metal chelates than the ligand.