Synthesis, Characterization, DNA Binding and Cytotoxicity of Copper(II) Phenylcarboxylate Complexes

Coordination compounds of copper exhibit cytotoxic activity and are suitable for the search for novel drug candidates for cancer treatment. In this work, we synthesized three copper(II) carboxylate complexes, [Cu2(3-(4-hydroxyphenyl)propanoate)4(H2O)2]·2H2O (C1), [Cu2(phenylpropanoate)4(H2O)2] (C2) and [Cu2(phenylacetate)4] (C3), and characterized them by elemental analysis and spectroscopic methods. Single-crystal X-ray diffraction of C1 showed the dinuclear paddle-wheel arrangement typical of Cu–carboxylate complexes in the crystal structure. In an aqueous solution, the complexes remain as dimeric units, as studied by UV-visible spectroscopy. The lipophilicity (partition coefficient) and the DNA binding (UV visible and viscosity) studies evidence that the complexes bind the DNA with low Kb constants. In vitro cytotoxicity studies on human cancer cell lines of metastatic breast adenocarcinoma (MDA-MB-231, MCF-7), lung epithelial carcinoma (A549) and cisplatin-resistant ovarian carcinoma (A2780cis), as well as a nontumoral lung cell line (MRC-5), indicate that the complexes are cytotoxic in cisplatin-resistant cells.