Quantitation of phenylalanine and itstrans-cinnamic, benzoic and hippuric acid metabolites in biological fluids in a single GC-MS analysis
| Autor: | Orval A. Mamer, Charles R. Scriver, Christineh N. Sarkissian |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Chromatography
Hippurates Phenylalanine Hippuric acid Endogeny Phenylalanine ammonia-lyase Benzoic Acid Deuterium Gas Chromatography-Mass Spectrometry Mice Mutant Strains Isotopomers Mice chemistry.chemical_compound chemistry Cinnamates Mouse Urine Biological fluids Animals Drug Therapy Combination Gas chromatography–mass spectrometry Spectroscopy Phenylalanine Ammonia-Lyase |
| Zdroj: | Journal of Mass Spectrometry. 42:811-817 |
| ISSN: | 1096-9888 1076-5174 |
| DOI: | 10.1002/jms.1218 |
| Popis: | We describe a sensitive, simple and convenient stable isotope dilution assay developed to study endogenous metabolism of administered stable isotope-labeled phenylalanine (Phe) in phenylketonuric (PKU) mice treated experimentally with phenylalanine ammonia lyase (PAL). Mouse urine and plasma containing endogenous and administered labeled Phe together with internal standard Phe bearing a different pattern of labeling are converted by in situ diazotization to 2-chloro-3-phenylpropionic acid (CPP). A single solvent extraction is then used to isolate the isotopomers of CPP along with the trans-cinnamic acid (TCA) produced from Phe by PAL, as well as the TCA metabolites benzoic and hippuric acids. This procedure eliminates the need for a separate ion-exchange isolation step for Phe on a second sample aliquot and separate GC-MS analysis. Extracted CPP and the Phe metabolites are then measured by conversion to the pentafluorobenzyl esters and a single analysis by electron capture negative ion GC-MS. The estimated lower limit of quantitation is 0.1 microM. |
| Databáze: | OpenAIRE |
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