Facile synthesis, structural characterization, DNA binding, incision evaluation, antioxidant and antimicrobial activity studies of Cobalt(II), Nickle(II) and Copper(II) complexes of 3-amino-5-(4-fluorophenyl)isoxazole derivatives

Abstract

Abstract A series of bivalent metal complexes [M(L1)2] and [M(L2)2] where M = Co(II), Ni(II), Cu(II) and newly synthesized Schiff bases L1 = (1-(5-(4-fluorophenyl)isoxazol-3-ylimino)methyl)napthalen-2-ol), L2 = (2-(5-(4-fluorophenyl)isoxazol-3-ylimino)methyl)-4-methylphenol) have been synthesized and characterized by elemental analysis, UV–Vis, FT-IR, Mass, NMR, ESR, magnetic moment, TGA, SEM and powder XRD analyses. Based on the spectral data, all the complexes adopted a square planar geometry around the metal ion. The interaction of metal complexes with CT–DNA was determined by using UV–absorption, fluorescence and viscosity measurements. And these results showed that the complexes moderately intercalate with CT–DNA. The DNA cleavage studies of metal complexes showed a significant cleavage of pBR322 DNA. The antioxidant activity of complexes was determined by DPPH• free radical scavenging assay. The antimicrobial activity of all the compounds was screened by disc diffusion method and it is found that the complexes showed better activity than the free ligands.