Spectroscopic and electrochemical investigation of ternary Cu (II) complex interaction with calf thymus DNA

Abstract

Aiming to design unique metallic drugs with significant therapeutic activity, in this work, mixed ligand Cu (II) complex involving 2,2′‐bipyridine and phenylalanine [Cu (bpy) (phenala.)Cl].2H2O has been fabricated and characterized using IR spectroscopy. The interaction of Cu (II) complex with CT‐DNA molecules was examined through UV–vis absorption titration plots, thermal denaturation experiments, viscosity measurements, and electrochemical studies. Cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry measurements have been exploited to elucidate their binding style. The negative potential shift in ΔE and E1/2 values as well as the increased current density of Cu (II)/Cu(I) redox couple suggested the promoted rate of electron transfer process in presence of CT‐DNA molecules in the examined solution. Some kinetic parameters were also estimated such as the diffusion coefficient, the exchange current density, and Tafel slope values. Based on the results of these binding experiments, a groove and/or electrostatic interaction mode was expected. The antimicrobial activity of the studied Cu (II) complex was screened against a series of bacteria and fungi. An outstanding performance was shown when treating different Gram‐positive and Gram‐negative bacteria types. Moreover, an enhanced cytotoxicity behavior toward some human tumor cell lines, including MCF7, HEPG2, and HFB4, was detected with respective IC50 values of 43.02, 51.21, and >200 μM when incubated with Cu (II) complex for 72 h. These results suggest the application of [Cu (bpy) (phenala.)Cl].2H2O complex as a chemotherapeutic agent with a promising output in the drug discovery field.