Investigation of Antimicrobial, Antioxidant, and DNA Binding Studies of Bioactive Cu(II), Zn(II), Co(II), and Ni(II) Complexes of Pyrimidine Derivative Schiff Base Ligand

A new pyrimidine based Schiff base ligand (HL) and its four complexes of type [MLOAc]·nH2O (Cu(II), 1; Zn(II), 2; Co(II), 3; and Ni(II), 4) have been synthesized and characterized by elemental analysis, MS, 1H-NMR, FT-IR, UV-visible, and ESR techniques. The electronic and ESR spectral data suggested that complexes 1–4 possess square planar geometry. Antimicrobial activities of HL and complexes 1–4 were tested against four bacteria (Staphylococcus aureus, Staphylococcus pneumonia, Salmonella enterica typhi, and Haemophilus influenzae) and two fungal strains (Aspergillus flavus and Aspergillus niger). These results show that complexes 1–4 have good antimicrobial activity compared to HL. The DNA cleavage activity of HL and complexes 1–4 was monitored by the agarose gel electrophoresis method. The antioxidant property of the prepared compounds was assessed by using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. DNA binding properties of HL and complexes 1–4 have been investigated by electronic absorption technique and viscometric measurements.