Synthesis, Characterization, Anti-Microbial and DNA Binding Studies on Mn(II) and Zn(II) Metal Complexes Containing Mixed Ligands.

Abstract

The DNA binding ability of the novel complexes Mn(L1)2L2(PF6)2[Complex (1) and Zn(L1)2L2(PF6)2 [Complex (2)] containing bioactive mixed ligand of typeL1=8-Hydroxyquinoline and L2=1,10-Phenanthroline have been isolated andcharacterized by analytical and spectral methods. The intrinsic binding constant Kb has been estimated at room temperature. The binding constant of the complexes in 5 mM Tris-HCl/50 mM NaCl buffer at pH 7.2, are 13.10× 106 M−1and 17.41× 106 M−1for complex (1) and (2) respectively. The absorption spectra indicate that the complexes intercalate between the base pairs of the CT-DNA tightly. The synthesized compounds have been tested againstmicroorganisms such as Gram positive bacteria (Staphylococcus aureus and Proteus vulgaris), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungus (Aspergillus niger). A comparative study of theMinimum Inhibitory Concentration(MIC) values of the ligands andtheir complexes indicates that the complexes exhibit moderate antimicrobial activity than the freeligand and control.