Copper(II)-Catalyzed Transamination of Hydrophobic Pyridoxamine with Pyruvic Acid in Functionalized Bilayer Vesicles

Article abstract of DOI:10.1246/bcsj.57.1116

The copper(II)-catalyzed transamination of 2-methyl-3-hydroxy-4-aminomethyl-5-(dodecylthiomethyl)pyridine (C12SPM) with sodium pyruvate was investigated in an aqueous medium at pH 6.8, μ 0.10 (KCl), and 30.0+/-0.1 deg C in the presence of molecular aggregates of N,N-ditetradecyl-N^α-<6-(trimethylammonio)hexanoyl>-L-alaninamide bromide (N(1+)C5Ala2C14), N,N-ditetradecyl-N^α-<6-(trimethylammonio)hexanoyl>-L-histidinamide bromide (N(1+)C5His2C14), or hexadecyltrimethylammonium bromide (CTAB).The reaction afforded the corresponding pyridoxal analogue (C12SPL) and alanine as the final products upon addition of edta which liberates the copper(II) ion from the coordination sites of the aldimine Schiff-base.The coordination interaction between the copper(II) ion and C12SPM, which takes place prior to the transamination, was clarified by electronic spectroscopy.The reactivity of the 2:1 (ketimine:Cu(II)) complex was found to be much larger than that of the 1: 1 complex in the molecular assemblies of N(1+)C5Ala2C14 and CTAB, and the formation of the former species was more pronounced in the N(1+)C5Ala2C14 vesicle.The bilayer vesicle formed with N(1+)C5His2C14 allowed the formation of the 1:1 complex in preference to that of the 2:1 complex, and the coordination-free imidazolyl group of the amphiphile effectively catalyzed the isomerization as a general base.

Full text of DOI:10.1246/bcsj.57.1116

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Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.