title: Stability of energy metabolites-An often overlooked issue in metabolomics studies: A review.
abstract: Recent advances in analytical chemistry have set the stage for metabolite profiling to help understand complex molecular processes in physiology. Despite ongoing efforts, there are concerns regarding metabolomics workflows, since it has been shown that internal (enzyme activity, blood contamination, and the dynamic nature of metabolite concentrations) as well as external factors (storage, handling, and analysis method) may affect the metabolome profile. Many metabolites are intrinsically instable, particularly some of those associated with central carbon metabolism. While enzymatic conversions have been studied in great detail, nonenzymatic, chemical conversions received comparatively little attention. This review aims to give an in-depth overview of nonenzymatic energy metabolite degradation/interconversion chemistry focusing on a selected range of metabolites. Special attention will be given to qualitative (degradation pathways) as well as quantitative aspects, that may affect the acquisition of accurate data in the context of metabolomics studies. Problems related to the use of isotopically labeled internal standards hindering the quantitative analysis of common metabolites will be presented with an experimental example. Finally, general conclusions and perspectives are given.
authors.affiliation: Analytical Biochemistry, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.
authors.forename: Andres
authors.initials: A
authors.lastname: Gil
authors.affiliation: Analytical Biochemistry, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.
authors.forename: David
authors.initials: D
authors.lastname: Siegel
authors.affiliation: Department of Pharmacy, Interfaculty Mass Spectrometry Center, University of Groningen, Groningen, The Netherlands.
authors.forename: Hjalmar
authors.initials: H
authors.lastname: Permentier
authors.affiliation: Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Dirk-Jan
authors.initials: DJ
authors.lastname: Reijngoud
authors.affiliation: Department of Pharmacy, Pharmaceutical Gene Modulation, University of Groningen, Groningen, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Dekker
authors.affiliation: Analytical Biochemistry, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.
authors.forename: Rainer
authors.initials: R
authors.lastname: Bischoff
keywords: Central carbon metabolism; Interconversion; Metabolomics; Nonenzymatic degradation; Preanalytical phase; Stability