A new ternary copper(II) complex derived from 2-(2′-pyridyl)benzimidazole and glycylglycine: Synthesis, characterization, DNA binding and cleavage, antioxidation and HSA interaction

• Non-covalent interactions of a new copper(II) complex with DNA and HSA were studied.
• The complex shows good DNA-binding, nuclease and SOD-like activity.
• The complex displays a desired affinity to HSA.
• Hydrogen bond or van der Waals power plays a major role in the HSA binding process.
• Binding induces conformational changes in the protein.

A new ternary copper(II)–dipeptide complex [Cu(glygly)(HPB)(Cl)]⋅2H2O (glygly = glycylglycine anion, HPB = 2-(2′-pyridyl)benzimidazole) has been synthesized and characterized. The DNA interaction of the complex was studied by spectroscopic methods, viscosity, and electrophoresis measurements. The antioxidant activity was also investigated using the pyrogallol autoxidation assay. Besides, the interaction of the complex with human serum albumin (HSA) in vitro was examined by multispectroscopic techniques. The complex partially intercalated to CT-DNA with a high binding constant (Kb = 7.28 × 105 M−1), and cleaved pBR322 DNA efficiently via an oxidative mechanism in the presence of Vc  , with the HO· and O2- as the active species, and the SOD as a promoter. Furthermore, the complex shows a considerable SOD-like activity with the IC50 value of 3.8386 μM. The complex exhibits desired binding affinity to HSA, in which hydrogen bond or vander Waals force played a major role. The alterations of HSA secondary structure induced by the complex were confirmed by UV–visible, CD, synchronous fluorescence and 3D fluorescence spectroscopy.

The DNA interaction of a new ternary copper(II) complex derived from 2-(2′-pyridyl)benzimidazole) and glycylglycine was studied by spectroscopic methods, viscosity, and electrophoresis measurements, and its antioxidant activity was evaluated using the pyrogallol autoxidation assay. The affinity of the complex to human serum albumin was also investigated via multispectroscopic techniques (UV–vis, fluorescence and CD spectroscopy).Figure optionsDownload as PowerPoint slide