Ruthenium(II) Complexes of Benzothiazolylthiosemicarbazones: Synthesis, Characterization, DNA-Binding, DNA Cleavage, and Cytotoxicity

Abstract

The new ruthenium(II) ferrocenyl heterocyclic thiosemicarbazone complexes of the type [RuCl(CO)(EPh₃)L] (where E = P/As; L = Monobasic tridendate thiosemicarbazone ligands) have been synthesized and structural features were determined by analytical and spectral techniques. Binding of these complexes with CT-DNA by absorption spectroscopy indicate that the ruthenium(II) complexes form adducts with DNA and has intrinsic binding constant in the range of 1.0–3.6 × 10⁴ M⁻¹. The complexes exhibit a remarkable DNA cleavage activity with pBR322 DNA in the presence of H₂O₂ and the efficiency was found to be dose dependent. In vitro cytotoxicity study of the complexes showed significant cytotoxicity against HeLa tumor line.

Keywords:

• ruthenium(II) complexes
• benzothiazolyl thiosemicarbazide
• DNA interaction
• cytotoxicity

Acknowledgments

The authors sincerely thank Council of Scientific and Industrial Research (CSIR), New Delhi, [Scheme. No. 01(2308)/09/EMR-II] for financial support.