Synthesis of Diquinolineno[1,3,7,9]Tetraazacyclododecine-7, 15 (14H, 16H)-Dibenzene, and DNA Binding Studies of Macrocyclic Co(II), Cu(II) Complexes: As New Class of Antimicrobial Agent

Abstract

The synthesis of macrocyclic ligand, diquinolineno[1,3,7,9]tetraazacyclododecine-7, 15 (14H, 16H)-dibenzene(L), is described. The metal complexes of the type [MLX₂], where (M = Co(II) (1), Cu(II) (2) and X = (Cl), have been synthesized by the reaction of ligand(L) with the corresponding metal salts, and characterized by elemental analysis, FT-IR, ¹H-NMR and electronic spectra. The binding property of the complexes with CT-DNA was studied by absorption spectra, viscosity measurements, as well as thermal denaturation studies. The absorption spectral results indicate that the complexes (1) and (2) are binds with base pairs of DNA. The intrinsic binding constant K_b had the value 3.8 × 10⁴M ⁻¹ for (1) and 3.3 × 10⁴ M⁻¹ for (2), respectively, in 5 mM Tris-HCl/50 mM NaCl buffer at pH 7.2. The viscosity measurement results show the viscosity of sonicated rod-like DNA fragments increased when the complex were added to the solution of calf thymus-DNA. The synthesized ligand and its metal complexes have been screened for antibacterial and antifungal activities.

Keywords:

• Quinoline
• macrocyclic complexes
• DNA binding
• viscosity measurements
• antimicrobial activity

Acknowledgments

Devappa S. Lamani thanks the Chairman, Department of Industrial Chemistry for providing a basic laboratory facility, the Indian Institute of Science Bangalore, India for providing spectral data and, Kuvempu University for awarding a Research Fellowship.