DNA binding and cleavage studies of copper(II) complex containing N₂O₂ Schiff base ligand

A new series of copper (II) complexes [Cu(L^1-5)](ClO₄)] [1–5] were synthesized by condensation of salicylaldehyde with various diamines (1,2-diamino ethane, 1,3-diamino propane, 1,2-diamino benzene, 2-aminobenzyl amine and 1,8-diamino naphthalene) and characterized by several analytical techniques. The precursor ligand structure was confirmed by single crystal X-ray diffraction (XRD) techniques. The viscosity measurement and molecular docking studies were also carried out for newly synthesized Cu(II) complexes. Cyclic voltametry (CV) study showed a quasi-reversible reduction wave in cathodic region confirm the presence of Cu²⁺. From the electronic spectral and DNA binding studies (K_b values are within the range from 0.47 × 10⁴ M⁻¹ to 1.18 × 10⁵ M⁻¹) it evidences that Cu(II) complexes were intercalated with DNA, this observation was further confirmed by fluorescence measurement studies (K_app∼0.22 × 10⁵ M ¹–0.26 × 10⁶ M⁻¹). Comparatively the maximum DNA cleavage was observed in the complex (5) and the possible mechanism of DNA cleavage activity has also been discussed. In addition, the interaction of complexes (1–5) with bovine serum albumin (BSA) was also examined. These encouraging results may pave the way towards the development of novel therapeutic agents in cancer biology.