Synthesis, DNA Binding, and Oxidative Cleavage Studies of Fe(II) and Co(III) Complexes Containing Bioactive Ligands

Abstract

The two complexes containing bioactive ligands of the type and [Fe(L)] (PF₆)₂ (1) (where L = [1-{[2-{[2-hydroxynaphthalen-1-yl)methylidine]amino}phenyl)imino] methyl}naphthalene-2-ol]) and [Co(L₁L₂)] (PF₆)₃ (2) (where L₁L₂ = mixed ligand of 2-seleno-4-methylquinoline and 1,10-phenanthroline in the ratio 1:2, respectively) were synthesized and structurally characterized. The DNA binding property of the complexes with calf thymus DNA has been investigated using absorption spectra, viscosity measurements, and thermal denaturation experiments. Intrinsic binding constant K_b has been estimated at room temperature. The absorption spectral studies indicate that the complexes intercalate between the base pairs of the CT-DNA tightly with intrinsic DNA binding constant of 2.8 × 10⁵ M⁻¹ for (1) and 4.8 × 10⁵ M⁻¹ for (2) in 5 mM Tris-HCl/50 mM NaCl buffer at pH 7.2, respectively. The oxidative cleavage activity of (1) and (2) were studied by using gel electrophoresis and the results show that complexes have potent nuclease activity.

Keywords:

• Fe(II) and Co(III) complexes
• DNA binding
• cleavage studies

Acknowledgments

The authors are thankful to Sri. B. Premanath Reddy, Chairman, Acharya Institutes, Prof. G. P. Prabhukumar, Principal, Acharya Institute of Technology, Bangalore, India, and the Department of Industrial Chemistry, Kuvempu University, Shankaraghatta, Shimoga, Karnataka, India.