Chlorine dioxide oxidations of tyrosine, N-acetyltyrosine, and dopa.

The reactions of aqueous ClO2 with tyrosine, N-acetyltyrosine, and dopa (3,4-dihydroxyphenylalanine) are investigated from pH 4 to 7. The reaction rates increase greatly with pH to give a series of oxidized products. Tyrosine and N-acetyltyrosine have similar reactivities with second-order rate constants (25.

Nickel(III) oxidation of its glycylglycylhistamine complex.

The doubly-deprotonated Ni(III) complex of Gly(2)Ha (where Ha is histamine) undergoes base-assisted oxidative self-decomposition of the peptide. At View Article and Find Full Text PDF

Decomposition kinetics of Ni(III)-peptide complexes with histidine and histamine as the third residue.

The decomposition kinetics of the Ni(III) complexes of Gly(2)HisGly and Gly(2)Ha are studied from p[H(+)] 3.5 to 10, where His is l-histidine and Ha is histamine. In these redox reactions, at least two Ni(III) complexes are reduced to Ni(II) while oxidizing a single peptide ligand.

Oxidative self-decomposition of the nickel(III) complex of glycylglycyl-L-histidylglycine.

Self-decomposition of the nickel(III) doubly deprotonated peptide complex of Gly2HisGly occurs by base-assisted oxidation of the peptide. At < or =p[H+] 7.0, the major pathway is a four-electron oxidation (via 4 Ni(III) complexes) at the alpha carbon of the N-terminal glycyl residue.