Antimicrobial,DNA cleavage,and antioxidant properties of new series of metal(II) complexes derived from naphthofuran-2-carbohydrazide Schiff base: synthesis and physico-chemical studies

Metal complexes of the type [NiL₂Cl₂]·H₂O and ML₂Cl₂ [M = Co(II), Cu(II), Cd(II), Zn(II), and Hg(II)] where L = Schiff base, derived from condensation of naphthofuran-2-carbohydrazide and 2-chloro-3-formylquinoline have been synthesized. The chelation of the complexes have been inferred through elemental analyses, IR, electronic mass, ¹H NMR, ESR spectral data, magnetic and thermal studies. The measured low molar conductance values in DMF indicate the complexes to be non-electrolytic in nature. The cyclic voltammetric investigation suggested that, the Cu(II) complex is of single electron transfer quasi-reversible nature. The free ligand and its complexes have been evaluated for their in vitro antibacterial and antifungal activities by minimum inhibitory concentration method. The influence of DNA cleavage on all the complexes was analyzed by agarose gel electrophoresis method. The free ligand with its complexes has been studied for their antioxidant activity by DPPH method. The results of bioassay revealed that, the metal complexes are active than the free ligand and their biological activity increases on complexation.