DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

• A novel mixed-ligand copper(II) complex has been synthesized and characterized.
• Two copper ions are bridged by sulfonate and exhibit square pyramidal geometries.
• 1 could bind to CT-DNA via intercalation and show efficient cleavage activity.
• 1 could arrest cell cycle in the S phase and induce apoptosis of MGC-803 cells.

A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV–vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV–vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and characterized. The interaction between 1 and DNA was investigated by UV–vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. In addition, 1 showed an antitumor effect on cell cycle and apoptosis.Figure optionsDownload as PowerPoint slide