Multinuclear magnetic resonance characterization and antiproliferative studies of novel dichlorido platinum(II) complexes containing kinetin riboside and 1-β-d-ribofuranosyl-4-(2-pyridyl)-1H-1,2,3-triazole

The chemical reaction between cis-[PtCl2(dmso)2] and kinetin riboside (KR) or 1-β-d-ribofuranosyl-4-(2-pyridyl)-1H-1,2,3-triazole (PTR) has resulted in two novel platinum(II) complexes being obtained with different compositions of the coordination sphere: cis-[PtCl2(PTR)] (1) and cis-[PtCl2(dmso)(KR)] (2). Based on multinuclear NMR results (1H, 13C, 15N, 195Pt), we have demonstrated that the N-donor ligands PTR and KR are able to coordinate to the Pt(II) ion as bidentate via two nitrogen atoms (N(3) and N(7)) or monodentate via only one nitrogen atom (N(7)), respectively. On the other hand, biological studies showed that the novel platinum(II) complexes exhibit different in vitro cytotoxicity towards A549 (lung carcinoma epithelial cells), T24 (urinary bladder cancer cells) and CRL1872 (malignant melanoma cells). The complex cis-[PtCl2(dmso)(KR)] (2) shows in vitro cytotoxicity against T24 and CRL1872 cell lines (the IC50 parameters amount to 52.2 μM and 21.4 μM, respectively), whereas cis-[PtCl2(PTR)] (1) is not able to inhibit a proliferation of these cells in the range of tested concentrations.