Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex

• Dicopper(II) adenine/phenanthroline complex (1) was synthesized.
• The structure was determined by single crystal X-ray diffraction.
• The complex 1 has remarkable IC50 values of 0.87 ± 0.06 μM (HeLa) and 0.44 ± 0.06 μM (Caco-2).
• The Cu(II) complex interacts with calf thymus DNA via the intercalation mode.

In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu₂(μ-adenine)₂(phen)₂(H2O)2](NO3)4·0.5H2O (phen = 1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu–Cu distance of 3.242(3) Å. Intramolecular and intermolecular π ⋯ π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87 ± 0.06 μM (HeLa) and 0.44 ± 0.06 μM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09 × 105 M− 1 was obtained from UV–vis absorption studies.

“A novel dinuclear Cu(II) complex containing both adenine and 1,10-phenanthroline has been designed, synthesized, characterized and evaluated for is in vitro anticancer activity. The complex was identified as a potent anti-proliferative agent against HeLa and Caco-2 cancer cells — IC50 values of 0.870 ± 0.06 and 0.44 ± 0.06 μM were determined by metabolic tests.”Figure optionsDownload as PowerPoint slide