Synthesis, characterization, DNA interaction and anti-bacterial studies of Cu(ii), Co(ii) and Ni(ii) metal complexes containing azo-dye ligand

The derivatives of the pyrazole and its metal complexes are considered a pharmacologically important active frame that possesses that some types of pharmacological activities. From the above review highlights the synthesis of pyrazole based ligand through, the diazotization reaction of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazole-3-one with aniline forms a new azo-dye ligand having N and O donor atoms and their transition metal complexes having the general formula [M(L2).nH2O] where, [M= Co(II),Cu(II), and Ni(II); L = 3-methyl-1-phenyl-4-[(E)-phenyldiazenyl]-4,5-dihydro-1H-pyrazole-5-ol]have been synthesized. The synthesized ligand and their metal complexes were characterized as by the melting point, solubility, elemental analyses, FT-IR, 1H and 13C NMR, UV-Visible spectroscopy, and Powder XRD techniques. The DNA binding studies of the metal complexes with Calf-thymus DNA has been studied using absorption spectra, viscosity measurements, and thermal denaturation methods. Absorption spectral studies indicate that metal complexes containing ligand intercalated between the base pairs of the CT-DNA tightly with intrinsic binding constant (Kb) in Tris - HCl buffer containing 50 mM NaCl buffer was found to be 4.8 × 105M−1, 3.89 × 105M−1and 3.26 × 105M−1 for Co(II) Cu(II) and Ni(II) complexes respectively. Furthermore, the photocleavage studies were carried out by using pUC - 19 DNA monitored by gel electrophoresis. The antibacterial activity was carried by a well-diffusion method against pathogenic organism's gram-negative Klebsiella pneumonia, gram-positive Bacillus subtilis.