Synthesis, Spectral Characterization, DNA Binding, DNA Cleavage, and Antioxidant Studies of Ruthenium(III) Heterocyclic Thiosemicarbazone Complexes

Abstract

The reactions of benzothiazolyl thiosemicarbazone with [RuX₃(PPh₃)₃] (X = Cl/Br) in a 1:1 molar ratio have given stable solid complexes corresponding to the general formula [RuX(PPh₃)₂(L)]. Structural features were determined by analytical and spectral techniques. DNA binding properties of the ligands and its ruthenium(III) complexes have been investigated by electronic absorption spectroscopy. The complexes show good binding affinity to calf-thymus DNA. Gel electrophories of pBR322 DNA with complexes demonstrated that the complexes exhibit excellent cleavage activity via oxidative pathway. In addition, the antioxidant activity of the free ligands and its complexes was determined by DPPH and hydroxyl radicals. The complexes were found to possess potent antioxidant activity.

Keywords:

• antioxidant studies
• DNA binding
• nuclease activity
• ruthenium(III) complexes