Synthesis, spectral characterization, in vitro antimicrobial evaluation and DNA cleavage studies of few macrocyclic complexes

Few macrocyclic complexes of the composition, [ML]X [M = Cu(II), Co(II), Ni(II), Mn(II), Zn(II), VO(IV), Cd(II) and Hg(II); X Cl(2)/SO(4)] have been designed and synthesized by the template condensation of malonic acid with 4,4'-diaminodiphenylmethane in ethanol medium. All the synthesized complexes were characterized by microanalytical data, magnetic susceptibility measurements, IR, UV-Vis, (1)H NMR, EPR and mass spectral techniques. They exhibit square-planar geometry except oxovanadium complex,. which has square-pyramidal geometry. The electrolytic behaviour and monomeric nature of the complexes were confirmed from their conductance data and magnetic susceptibility. The X-band EPR spectra of Cu(II), Mn(II), Co(II) and VO(IV) complexes in DMSO at 300 and 77 K were recorded and their salient features are reported. The in vitro antimicrobial activities of the investigated compounds were evaluated against few microorganisms by well-diffusion technique. It was found that the metal complexes have higher activity than the standard. The cleavage activity of all the complexes was examined on pUC19 DNA using gel electrophoresis experiment in the presence of H(2)O(2). From the data, it was found that all the complexes exhibit nuclease activity except vanadyl complex in the presence of H(2)O(2).