Structural studies and cytotoxic activity against human cancer cell lines of mono and dinuclear tin(IV) complexes with the α,α′-dimercapto-o-xylene ligand

•Two organotin(IV) compounds (mononuclear and dinuclear) with the α,α′-dimercapto-o-xylene ligand have been synthesized.•The cytotoxic activity of the compounds against different human cancer cell lines is very high.•The cytotoxicity of the dinuclear compound is higher than that of the mononuclear compound.•The dinuclear compound is less toxic to immunocompetent cells than cytotoxic against human cancer cell lines.

The reaction of α,α′-dimercapto-o-xylene (H2dmox) with SnPh2Cl2 (1:1) and SnPh3Cl (1:2) in the presence of two equivalents of NEt3 led to the formation of the complexes [SnPh2(dmox)] (1) and [SnPh3(μ-dmox)]2 (2), respectively. Both complexes have been characterized by multinuclear NMR and IR spectroscopy, mass spectrometry and elemental analysis. In addition, the molecular structure of complex 2 has been determined by single crystal X-ray diffraction studies. The cytotoxic activity of 1 and 2 was tested against the tumor cell lines human cervix adenocarcinoma HeLa, breast carcinoma MDA-MB-453, colon carcinoma LS174 and human myelogenous leukemia K562. In addition, the toxicity of both complexes to non-stimulated and stimulated peripheral blood mononuclear cells (PBMC) has been tested. The in vitro cytotoxicity tests show very high antiproliferative activity of both complexes, being much higher that of 2. In addition, this compound shows a higher cytotoxic activity towards cancer cell lines than to non-stimulated and stimulated PBMC, indicating a slight selectivity to cancer cell lines.

Graphical abstractA mononuclear and a dinuclear complex containing the α,α′-dimercapto-o-xylene ligand have been synthesized and characterized. The biological studies of these two complexes show a high cytotoxic activity against a wide variety of human tumor cell lines and moderate toxicity of both complexes to peripheral blood mononuclear cells.Figure optionsDownload full-size imageDownload as PowerPoint slide