title: Differential Off-line LC-NMR (DOLC-NMR) Metabolomics To Monitor Tyrosine-Induced Metabolome Alterations in Saccharomyces cerevisiae.
abstract: A novel differential off-line LC-NMR approach (DOLC-NMR) was developed to capture and quantify nutrient-induced metabolome alterations in Saccharomyces cerevisiae. Off-line coupling of HPLC separation and1H NMR spectroscopy supported by automated comparative bucket analyses, followed by quantitative1H NMR using ERETIC 2 (electronic reference to access in vivo concentrations), has been successfully used to quantitatively record changes in the metabolome of S. cerevisiae upon intervention with the aromatic amino acid l-tyrosine. Among the 33 metabolites identified, glyceryl succinate, tyrosol acetate, tyrosol lactate, tyrosol succinate, and N-acyl-tyrosine derivatives such as N-(1-oxooctyl)-tyrosine are reported for the first time as yeast metabolites. Depending on the chain length, N-(1-oxooctyl)-, N-(1-oxodecanyl)-, N-(1-oxododecanyl)-, N-(1-oxomyristinyl)-, N-(1-oxopalmityl)-, and N-(1-oxooleoyl)-l-tyrosine imparted a kokumi taste enhancement above their recognition thresholds ranging between 145 and 1432 μmol/L (model broth). Finally, carbon module labeling (CAMOLA) and carbon bond labeling (CABOLA) experiments with13C6-glucose as the carbon source confirmed the biosynthetic pathway leading to the key metabolites; for example, the aliphatic side chain of N-(1-oxooctyl)-tyrosine could be shown to be generated via de novo fatty acid biosynthesis from four C2-carbon modules (acetyl-CoA) originating from glucose.
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Strasse 34, D-85354 Freising-Weihenstephan, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Hammerl
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Strasse 34, D-85354 Freising-Weihenstephan, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Frank
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Strasse 34, D-85354 Freising-Weihenstephan, Germany.
authors.forename: Thomas
authors.identifier: http://orcid.org/0000-0003-4057-7165
authors.initials: T
authors.lastname: Hofmann
mesh_terms: D000085:Acetates / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D000085:Acetates; D014443:Tyrosine; D005947:Glucose
keywords: 13C-labeling; CABOLA; CAMOLA; DOLC-NMR; Saccharomyces cerevisiae; kokumi; qNMR; quantitative NMR; taste; yeast