Metabolization of Free Oxidized Aromatic Amino Acids by Saccharomyces cerevisiae
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
The aromatic amino acids tryptophan, phenylalanine, and tyrosine are targets for oxidation during food processing. We investigated whether S. cerevisiae can use nonproteinogenic aromatic amino acids as substrates for degradation via the Ehrlich pathway. The metabolic fate of seven amino acids (p-, o-, m-tyrosine, 3,4-dihydroxyphenylalanine (DOPA), 3-nitrotyrosine, 3-chlorotyrosine, and dityrosine) in the presence of S. cerevisiae was assessed. All investigated amino acids except dityrosine were metabolized by yeast. The amino acids 3-nitrotyrosine and o-tyrosine were removed from the medium as fast as p-tyrosine, and m-tyrosine, 3-chlorotyrosine, and DOPA more slowly. In summary, 11 metabolites were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS). DOPA, 3-nitrotyrosine, and p-tyrosine were metabolized predominantly to the Ehrlich alcohols, whereas o-tyrosine and m-tyrosine were metabolized predominantly to α-hydroxy acids. Our results indicate that nonproteinogenic aromatic amino acids can be taken up and transaminated by S. cerevisiae quite effectively but that decarboxylation and reduction to Ehrlich alcohols as the final metabolites is hampered by hydroxyl groups in the o- or m-positions of the phenyl ring. The data on amino acid metabolism were substantiated by the analysis of five commercial beer samples, which revealed the presence of hydroxytyrosol (ca. 0.01-0.1 mg/L) in beer for the first time.
Details
Original language | English |
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Pages (from-to) | 5766-5776 |
Number of pages | 11 |
Journal | Journal of agricultural and food chemistry |
Volume | 72 |
Issue number | 11 |
Publication status | Published - 20 Mar 2024 |
Peer-reviewed | Yes |
External IDs
PubMed | 38447044 |
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ORCID | /0000-0001-8528-6893/work/173516449 |
Keywords
ASJC Scopus subject areas
Keywords
- 3-chlorotyrosine, 3-nitrotyrosine, beer, dityrosine, fermentation, m-tyrosine, metabolism, o-tyrosine, protein oxidation, tyrosine, yeast