title: Discovery of N(2)-(1-carboxyethyl)guanosine 5'-monophosphate as an umami-enhancing maillard-modified nucleotide in yeast extracts.
abstract: Sensory-guided fractionation of a commercial yeast extract involving medium-pressure RP-18 chromatography and ion-pair chromatography, followed by LC-MS/MS, LC-TOF-MS, 1D/2D-NMR, and CD spectroscopy, led to the discovery of the previously not reported umami-enhancing nucleotide diastereomers (R)- and (S)-N(2)-(1-carboxyethyl)guanosine 5'-monophosphate. Model experiments confirmed the formation of these diastereomers by a Maillard-type glycation of guanosine 5'-monophosphate with dihydroxyacetone and glyceraldehyde, respectively. Sensory studies revealed umami recognition threshold concentrations of 0.19 and 0.85 mmol/L for the (S)- and (R)-configured diastereomers, respectively, and demonstrated the taste-enhancing activity of these nucleotides on monosodium l-glutamate solutions.
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Strasse 34, D-85354 Freising-Weihenstephan, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Festring
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
mesh_terms: D000328:Adult; D005591:Chemical Fractionation; D005260:Female; D005421:Flavoring Agents; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D006801:Humans; D015416:Maillard Reaction; D008297:Male; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D013237:Stereoisomerism; D013649:Taste
chemical_list: D005421:Flavoring Agents; C555524:N(2)-(1-carboxyethyl)guanosine 5'-monophosphate; D006157:Guanosine Monophosphate