Water soluble copper(II) complex [Cu(dipica)(CH3COO)]ClO4: DNA binding, pH dependent DNA cleavage and cytotoxicity

•Water soluble copper(II) complex•Possess near square planar geometry in solution.•Groove binding mode of interaction with CT DNA•Effective DNA damage only at acidic pH.•Cytotoxic to HeLa cancer cells while non-toxic to normal cells.

A mononuclear copper(II) complex [Cu(dipica)(CH3COO)]ClO4 (1), where dipica is di-(2-picolyl)amine, has been isolated. The electronic absorption (646 nm) and electron paramagnetic resonance (EPR) spectral parameters (g||, 2.223; A||, 187 × 10− 4 cm− 1; g||/A||, 119 cm) reveal that 1 possesses a near square planar geometry with CuN3O chromophore. Absorption, circular dichroic and emission spectral measurements and electrochemical measurements clearly demonstrate groove binding of 1 to calf thymus DNA. Notably, 1 exhibits more effective DNA (pUC 19 DNA) cleavage at acidic pH. It shows significant cytotoxicity (IC50, 55 μM) against human cervical carcinoma cells (HeLa) at 48 h incubation time and is non-toxic to healthy cells.

Graphical abstractThe water soluble copper(II) complex is involved in groove binding with CT DNA. It shows a profound efficiency to cleave plasmid DNA at acidic pH. It is cytotoxic to HeLa cancer cells whereas it is non-toxic to normal cells.Figure optionsDownload full-size imageDownload as PowerPoint slide