title: The degradation of nucleotide triphosphates extracted under boiling ethanol conditions is prevented by the yeast cellular matrix.
abstract: BACKGROUND
  Boiling ethanol extraction is a frequently used method for metabolomics studies of biological samples. However, the stability of several central carbon metabolites, including nucleotide triphosphates, and the influence of the cellular matrix on their degradation have not been addressed.
  
  
  OBJECTIVE
  To study how a complex cellular matrix extracted from yeast (Saccharomyces cerevisiae) may affect the degradation profiles of nucleotide triphosphates extracted under boiling ethanol conditions.
  
  
  METHODS
  We present a double-labelling LC-MS approach with a13C-labeled yeast cellular extract as complex surrogate matrix, and13C15N-labeled nucleotides as internal standards, to study the effect of the yeast matrix on the degradation of nucleotide triphosphates.
  
  
  RESULTS
  While nucleotide triphosphates were degraded to the corresponding diphosphates in pure solutions, degradation was prevented in the presence of the yeast matrix under typical boiling ethanol extraction conditions.
  
  
  CONCLUSIONS
  Extraction of biological samples under boiling ethanol extraction conditions that rapidly inactivate enzyme activity are suitable for labile central energy metabolites such as nucleotide triphosphates due to the stabilizing effect of the yeast matrix. The basis of this phenomenon requires further study.
authors.affiliation: Department of Pharmacy, Analytical Biochemistry, University of Groningen, Antonius Deusinglaan 1, Building 3226, Room 601, 9713 AV Groningen, The Netherlands.
authors.forename: Andres
authors.initials: A
authors.lastname: Gil
authors.affiliation: Department of Pharmacy, Analytical Biochemistry, University of Groningen, Antonius Deusinglaan 1, Building 3226, Room 601, 9713 AV Groningen, The Netherlands.
authors.forename: David
authors.initials: D
authors.lastname: Siegel
authors.affiliation: Biomolecular Sciences and Biotechnology Institute, Molecular Systems Biology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Silke
authors.initials: S
authors.lastname: Bonsing-Vedelaar
authors.affiliation: Department of Pharmacy, Interfaculty Mass Spectrometry Center, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Hjalmar
authors.initials: H
authors.lastname: Permentier
authors.affiliation: University Medical Center Groningen, Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands.
authors.forename: Dirk-Jan
authors.initials: DJ
authors.lastname: Reijngoud
authors.affiliation: Department of Pharmacy, Pharmaceutical Gene Modulation, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Dekker
authors.affiliation: Department of Pharmacy, Analytical Biochemistry, University of Groningen, Antonius Deusinglaan 1, Building 3226, Room 601, 9713 AV Groningen, The Netherlands.
authors.forename: Rainer
authors.initials: R
authors.lastname: Bischoff
keywords: Boiling ethanol extraction; Mass spectrometry; Metabolomics; Nucleotides; Stability