title: GC-MS Method for the Quantitation of Carbohydrate Intermediates in Glycation Systems.
abstract: Glycation is a ubiquitous nonenzymatic reaction of carbonyl compounds with amino groups of peptides and proteins, resulting in the formation of advanced glycation end-products (AGEs) and thereby affecting the properties and quality of thermally processed foods. In this context, mechanisms of the Maillard reaction of proteins need to be understood; that is, glycation products and intermediates (α-dicarbonyls and sugars) need to be characterized. Although the chemical analysis of proteins, peptides, and α-dicarbonyls is well established, sensitive and precise determination of multiple sugars in glycation mixtures is still challenging. This paper presents a gas chromatography-mass spectrometry (GC-MS) method for absolute quantitation of 22 carbohydrates in the model of phosphate-buffered glycation systems. The approach relied on the removal of the phosphate component by polymer-based ion exchange solid phase extraction (SPE) followed by derivatization of carbohydrates and subsequent GC-MS analysis. Thereby, baseline separation for most of the analytes and detection limits of up to 10 fmol were achieved. The method was successfully applied to the analysis of in vitro glycation reactions. Thereby, at least seven sugar-related Maillard reaction intermediates could be identified and quantified. The most abundant reaction product was d-fructose, reaching 2.70 ± 0.12 and 2.38 ± 0.66 mmol/L after 120 min of incubation in the absence and presence of the model peptide, respectively.
authors.affiliation: †Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, ‡Center for Biotechnology and Biomedicine (BBZ), and #Institute of Analytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Sanja
authors.initials: S
authors.lastname: Milkovska-Stamenova
authors.affiliation: †Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, ‡Center for Biotechnology and Biomedicine (BBZ), and #Institute of Analytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Rico
authors.initials: R
authors.lastname: Schmidt
authors.affiliation: †Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, ‡Center for Biotechnology and Biomedicine (BBZ), and #Institute of Analytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Andrej
authors.initials: A
authors.lastname: Frolov
authors.affiliation: †Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, ‡Center for Biotechnology and Biomedicine (BBZ), and #Institute of Analytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Birkemeyer
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D017127:Glycation End Products, Advanced / Q000737:chemistry; D006031:Glycosylation; D015416:Maillard Reaction; D013058:Mass Spectrometry; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D017127:Glycation End Products, Advanced; D010455:Peptides
keywords: carbohydrates; gas chromatography−mass spectrometry; glycation; phosphate removal; solid phase extraction