Degradation of tetrahydro-beta-carbolines in the presence of nitrite: HPLC-MS analysis of the reaction products
| Autor: | Birgit Gutsche, Stefanie Diem, Markus Herderich |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Indole test
Reaction mechanism Nitroso Compounds Molecular Conformation General Chemistry Nitroso Mass Spectrometry chemistry.chemical_compound Harmine Kinetics chemistry Organic chemistry Amine gas treating Reactivity (chemistry) Nitrite General Agricultural and Biological Sciences Oxidative decarboxylation Chromatography High Pressure Liquid Food Analysis Nitrites Carbolines |
| Zdroj: | Journal of agricultural and food chemistry. 49(12) |
| ISSN: | 0021-8561 |
| Popis: | Motivated by the identification of numerous novel tetrahydro-beta-carboline-carboxylic acids in food samples, we studied the reactions of tetrahydro-beta-carbolines in the presence of nitrosating agents. The anticipated formation of nitroso derivatives from unsubstituted tetrahydro-beta-carbolines, and from tetrahydro-beta-carboline-3-carboxylic acids was indicated by HPLC-MS/MS analysis and validated by the characteristic product ion spectra of the respective nitroso compounds. In addition, oxidative decarboxylation resulted in formation of the corresponding dihydro-beta-carbolines, and in the generation of the beta-carbolines harman or norharman. Subsequently, we studied the reactivity of tetrahydro-beta-carboline-1-carboxylic acids derived from the Pictet-Spengler condensation of indole amines with alpha-oxo acids. Again, in the presence of nitrosating agents the rapid disappearance of the starting material was obvious, but no nitroso derivatives could be observed. Instead, further HPLC-MS/MS studies demonstrated that dihydro-beta-carbolines were the major products of tetrahydro-beta-carboline-1-carboxylic acids. Finally, we demonstrated that freshly isolated nitroso-precursors spontaneously decomposed to yield harman alkaloids. In conclusion, we revealed that nitroso-tetrahydro-beta-carbolines can represent intermediates involved in the generation of beta-carbolines, and we established a novel pathway for the formation of harman alkaloids from nutritional tetrahydro-beta-carbolines. |
| Databáze: | OpenAIRE |
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