Fast-atom-bombardment mass spectrometry and1H-NMR spectrometry in studies of the transformations of thiamine in strongly basic solutions
| Autor: | Ian Horman |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Chemistry
Organic Chemistry Analytical chemistry Nuclear magnetic resonance spectroscopy Fast atom bombardment Mass spectrometry Biochemistry Catalysis Inorganic Chemistry Reaction rate constant Basic solution Drug Discovery Mass spectrum Proton NMR Organic chemistry Thiamine Physical and Theoretical Chemistry |
| Zdroj: | Helvetica Chimica Acta. 67:1478-1483 |
| ISSN: | 1522-2675 0018-019X |
| DOI: | 10.1002/hlca.19840670609 |
| Popis: | Fast-atom-bombardment (FAB) mass spectra have been used to establish or confirm the nature of the yellow-product and open-chain forms of thiamine produced in the presence of excess (5 mol-equivb.) of strong base. Time-dependent changes in 1H-NMR spectra show that the rates of disappearance of the yellow form and of formation of the open-chain form are the same at pH 12.5, having a pseudo-first-order rate constant of k = 2.2 × 10−3 sec−1. The implications of these results are discussed in the light of current ideas on the acid-base dependence of thiamine structures. |
| Databáze: | OpenAIRE |
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