Hydrogen halide assisted formation of peptide disulfides by a platinum(IV) complex oxidation in aqueous medium, a mechanistic study

A new Pt(IV) complex trans-[Pt(OH)2(phen)(en)]2+ was synthesized and characterized by elemental analysis, MS and 1H NMR. It was used as an oxidant for construction of disulfide bond in peptide in various solutions. When the oxidation reaction was carried out in HBr solution, the highest oxidation rate and yield were achieved; no side reactions were occurred on the side chain of methionine, tyrosine and tryptophan residues of peptide. A novel reaction mechanism was proposed through the HPLC studies. A novel reaction mechanism for formation of peptide disulfide bond by trans-[Pt(OH)2(phen)(en)]2+ oxidation in HBr solution was proposed according the HPLC studies. [Display omitted] •A new Pt(IV) complex was used for construction of peptide disulfides.•The reaction rate was increased with the trend of HBr > HCl > KBr > KCl > H2O.•A novel reaction mechanism was proposed through the HPLC studies.