Synthesis, characteri̇zation and dna interaction of 2,1,3-benzothi̇adi̇azole derivatives

In this study, the synthesis of 4-bromo-7-imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzo[c][1,2,5] thiodiazole ligand and its nickel metal complex, characterization and DNA interactions have been studied. The characterization of the ligands was carried out by FT-IR, 1H-NMR, 13C-NMR, ESI-MS analysis methods. DNA interactions of compounds were studied by UV-Vis titration, fluorescence, viscosimetry and agarose gel electrophoresis methods. UV-Vis titration results show that the complex binds to DNA as a groove binder. As well as this the complex electrostatically interacts with DNA. The binding constant is 6.4 × 105 M-1. Viscosimetry studies support this result. According to the fluorescence studies, the complex synthesized was found to be a weak groove binder. In the electrophoresis studies, the complex by itself did not cause any breakage on the DNA. However, it caused the DNA precipitation at high concentrations. In the presence of peroxide, the complex resulted severe DNA damage along with the precipitation at high concentrations. It is thought that the positive charges of the complex may have neutralized by closing the negative charges of DNA.