DNA interaction studies of pyrazolone- and diimine-incorporated Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes: synthesis, spectroscopic characterization, and antimicrobial study

Abstract

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) mixed-ligand complexes were synthesized using 4-((furan-2- ylmethylene)amino)-1,2-dihydro-1,5-dimethyl-2-phenyl-3H- pyrazol-3-one as the main ligand and 1,10-phenanthroline/ 2,2 0 -bipyridine as co-ligand(s). They were characterized by the usual analytical and spectral techniques. The data obtained reveal that the complexes adopt an octahedral geometry around the central metal ions. These complexes were found to be better antimicrobial agents than the free ligands. The DNA (CT) binding properties of the com- plexes were explored by UV-Vis, viscosity measurements, cyclic voltammetry, differential pulse voltammetry, and molecular docking studies. Binding constants for the above complexes were found to be on the order of 10 4 , indicating that most of the synthesized complexes are partial inter- calators. The DNA-cleavage activities of the complexes were also assessed using supercoiled pUC19 DNA and gel electrophoresis, and the results revealed that the hydroxyl radical is likely to be the reactive species responsible for the cleavage of pUC19 DNA by the synthesized