An NMR spectroscopic investigation of the oxidation reactions ofDL-selenomethionine
| Autor: | H. A. Zainal, R. M. Waters, W. R. Wolf |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Hydrogen bond General Chemical Engineering Chemical shift Organic Chemistry Inorganic chemistry Carbon-13 NMR Pollution Medicinal chemistry Redox Inorganic Chemistry chemistry.chemical_compound Fuel Technology chemistry Basic solution Proton NMR Hydrogen peroxide Waste Management and Disposal Bond cleavage Biotechnology |
| Zdroj: | Journal of Chemical Technology & Biotechnology. 72:38-44 |
| ISSN: | 1097-4660 0268-2575 |
| DOI: | 10.1002/(sici)1097-4660(199805)72:1<38::aid-jctb863>3.0.co;2-r |
| Popis: | Oxidation reactions of DL-selenomethionine (DL-SeMet) with hydrogen peroxide and ozone were investigated by 1H and 13C NMR spectroscopy. Chemical shifts of the reaction products were measured at different pD values in D2O solutions. In the moderate (4–8) pD range, a pair of singlets of equal intensity appeared at 2·71 and 2·80 ppm, with the disappearance of the DL-SeMet methyl peak at 2·04 ppm. As the pD of the solution decreased, the chemical shifts of both peaks increased relative to 3-trimethylsilylpropionic acid-d4 sodium salt. In strongly acidic solutions (pD 10). These data were assigned to Met selenoxide in basic solution, stabilized by intermolecular hydrogen bonding, and to the hydration of Met selenoxide to Met dihydroxyselenide in acidic solutions. In moderate pD solutions (pD = 4–8), both forms of the selenoxide can exist. For the reaction of DL-SeMet with CNBr, two parallel reactions occur, i.e. oxidation and bond cleavage with cyanization: the bond cleavage giving the expected products, i.e. 2-amino-4-butyrolactone and methyl selenocyanate, with an additional singlet observed at 2·54 ppm. © 1988 SCI |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text