Crystal structure, DNA-binding ability and cytotoxic activity of platinum(II) 2,2′-dipyridylamine complexes

Two platinum(II) complexes, [Pt(dpa)Cl2] (1) and [Pt(dpa)CBDCA] (2), where DPA=2,2′-dipyridylamine and CBDCA=1,1-cyclobutanedicarboxylate, were synthesized and characterized by elemental analysis, IR spectroscopy, ES-MS and X-ray diffraction. Intermolecular hydrogen bonds were observed in both complexes (N–H⋯Cl for complex 1 and N–H⋯O for complex 2), which may play a role in formation of hydrogen bonding in metal–DNA adducts. Complex 2 adopts a boat conformation so that the cyclobutane ring and bipyridyl groups are on the same side of the platinum square. The interactions of complexes 1 and 2 with DNA were studied by UV and Fluorescence Spectroscopy, which indicated that both complexes could interact with DNA through groove binding or intercalation. The in vitro cytotoxic activity against melanoma B16-BL6 cells and human Jurkat T-cells was also reported.