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A 13 C NMR study of pyridoxal‐5′‐phosphate oxime
Author(s) -
Korpela Timo,
Lundell Juhani,
Mäkinen Eila
Publication year - 1979
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270120610
Subject(s) - oxime , tautomer , chemistry , titration , schiff base , pyridoxal , chemical shift , carbon 13 nmr , phosphate , proton nmr , organic chemistry , stereochemistry
Pyridoxal‐5′‐phosphate amino‐oxy acetate oxime was titrated in water, over the pH range 4–12, and the changes followed using 13 C NMR. The results were compared to those of analogous Schiff's bases presented in the literature. The chemical shifts and titration curves of the oxime were appreciably different from those of the Schiff's bases, and the differences are explained as being due to the absence of ketoenamine‐enolimine tautomerism in the oxime. The low chemical shift value and the large changes of the oxime azomethine carbon during titration, as compared to the Schiff's bases, are discussed. The high stability of the oximes in water makes them suitable as model compounds for some tautomeric forms of the Iess stable Schiff's bases.