title: Novel polynuclear platinum adducts detected during the reactions of [Pt(Met-S,N)Cl2] with gamma-glutathione and L-cysteine.
abstract: The reactions of platinum(II) complexes with thiol containing molecules are highly relevant to the mechanism of action of platinum-based drugs. This work presents the electrospray mass spectrometry (ESMS) and NMR results on the reactions of [Pt(l-MetH-S,N)Cl(2)] (l-MetH: l-methionine) with gamma-glutathione (GSH) and l-cysteine (l-Cys) at different pH and different molar ratios. Polymeric species such as [Pt(2)(micro-SG-S)(2)(Met-S,N)(2)], [Pt(3)(micro-SG-S)(4)(Met-S,N)(2)], [Pt(4)(micro-SG-S)(6)(Met-S,N)(2)] and [Pt(5)(micro-SG-S)(8)(Met-S,N)(2)] (l-Met: deprotonated l-methionine) were detected and were stable for long hours. For both reactions, the polymerization extent decreased with the increase of pH. For the reaction of l-Cys, only mononuclear complex [Pt(l-Met-S,N)(l-Cys-S,N)] was observed when pH>9. The observation and identification of polymeric (higher than binuclear) adducts of Pt(II)/GSH and Pt(II)/l-Cys appears to be unprecedented.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, 210093 Nanjing, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Haiying
authors.initials: H
authors.lastname: Wei
authors.forename: Jun
authors.initials: J
authors.lastname: Lin
authors.forename: Longgen
authors.initials: L
authors.lastname: Zhu
authors.forename: Zijian
authors.initials: Z
authors.lastname: Guo
mesh_terms: D002945:Cisplatin / Q000737:chemistry / Q000633:toxicity; D003545:Cysteine / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D017671:Platinum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D017671:Platinum Compounds; D005978:Glutathione; D003545:Cysteine; D002945:Cisplatin