Platinum(II) carboxylato complexes containing 7-azaindoles as N-donor carrier ligands showed cytotoxicity against cancer cell lines.

The platinum(II) malonato (Mal) and decanoato (Dec) complexes of the general formulas [Pt(Mal)(naza)] (1-3) and cis-[Pt(Dec)(naza)] (4-7) were prepared, characterized and tested for their in vitro cytotoxicity against cisplatin-sensitive (A2780) and cisplatin-resistant (A2780R) human ovarian carcinoma cell lines and non-cancerous human lung fibroblasts (MRC-5); naza=halogeno-derivatives of 7-azaindole. Complexes 1-7 effectively overcome the acquired resistance of ovarian carcinoma cells to cisplatin. Complexes 2 (IC=26.6±8.9μM against A2780 and 28.9±6.7μM against A2780R), 4 (IC=14.5±0.6μM against A2780 and 14.5±3.8μM against A2780R) and 5 (IC=13.0±1.1μM against A2780 and 13.6±4.9μM against A2780R) indicated decreased toxicity against healthy MRC-5 cells (IC>50.0μM for 2 and >25.0μM for 4 and 5). The representative complexes 2 and 4 showed mutually different effect on the A2780 cell cycle at IC concentrations after 24h exposure. Concretely, the complex 2 caused cell cycle arrest at G/G phase, while 4 induced cell death by apoptosis with high population of cells in sub-G cell cycle phase. The hydrolysis and interactions of the selected complexes with biomolecules (glutathione (GSH) and guanosine monophosphate (GMP)) were also studied by means of H NMR and ESI+ mass spectra.