POTENTIALLY BIOACTIVE SCHIFF BASE TRANSITION METAL(II) COMPLEXES AS SELECTIVE DNA BINDING, CLEAVAGE, IN VITRO ANTIMICROBIAL AND IN VITRO ANTIOXIDANT AGENTS

Cu(II), Ni(II) and VO(II) complexes have been synthesized using 4,4'-Bis-[1-ethyl-2-(2-hydroxy-phenylimino)- propylideneamino]-biphenyl-3,3'-diol as a ligand derived from 3, 3′-dihydroxybenzidine, 2, 3- pentanedione and 2- aminophenol. All the metal complexes have been fully characterized with the help of analytical, conductivity, IR, electronic, magnetic, ESR and NMR studies. The Schiff bases are found to act as a tetradentate ligand using N2O2 donor set of atoms leading to a square-planar geometry for the Cu(II), Ni(II) and square pyramidal for VO(II) complexes. Their biological efficacy as antibacterial, antifungal, antioxidant, DNA cleavage and interaction with CTDNA was carried out, and showed remarkable activities in each area of research. The binding properties of metal complexes with DNA have been investigated by electronic absorption spectra and viscosity measurements showing that the complexes have the ability of interaction with DNA by intercalative mode. All the metal complexes cleave the pUC18DNA in presence of H2O2. The antibacterial activity of these compounds was studied in vitro by the disc diffusion assay against two Gram-positive bacteria like Staphylococcus aureus, Bacillus subtilis and two Gram-negative bacteria like Escherichia coli and Klebsilla pneumonia, where as the antifungal against Fusarium oxysporum and Aspergillus fumigates. Additionaly, the antioxidant activities of the complexes were also investigated through scavenging effect on DPPH, OH radicals, ABTS and reducing power activity.