Pt(II) complexes with N-(3-pyridyl)-2-(4-(trifluoromethyl)phenyl)diazenecarboxamide and their reactions with glutathione

Abstract

The reaction between [PtCl(dmso)(en)]Cl (dmso=dimethyl sulfoxide, en=ethylenediamine) and N-(3-pyridyl)-2-(4-(trifluoromethyl)phenyl)diazenecarboxamide ( L) was studied using multinuclear NMR spectroscopy. The water-soluble complexes [PtCl(en)(L- N1)] + ( 1) and [Pt(en)(L- N1) 2] 2+ ( 2) were isolated and their reactions with glutathione (GSH) were investigated to assess the oxidation properties of coordinated L. Both species 1 and 2 oxidized GSH to GSSG, while the reduced form of L (semicarbazide, SL) remained coordinated to Pt 2+. In complex 1 the labile chloride ion was substituted by the thiol moiety of GSH, which gave rise to the release of en in excess GSH over a period of 7 days. Complexes [PtCl(dmso)(en)]Cl, 1, 2 and ligand L were tested against T24 bladder carcinoma cells. Ligand L and complexes 1 and 2 showed higher cytotoxicity than [PtCl(dmso)(en)]Cl.