Tryptophan-N-glucoside in fruits and fruit juices.
In extracts prepared from various fruits as well as in fruit juices a single tryptophan glycoconjugate was detected by HPLC-MS analysis. Product ion spectra demonstrated the N-glycosidic linkage of a hexose moiety to the indole nitrogen. For structure elucidation, the novel tryptophan glycoside was isolated from pear juice and identified as N(1)-(beta-D-glucopyranosyl-(4)C(1))-L-tryptophan by (1)H, HH-COSY and (13)C NMR spectroscopy. Finally, we disclosed the biosynthetic origin of the novel tryptophan metabolite by demonstrating the enzymatic glycosylation of deuterium-labeled tryptophan, which was applied to pear fruit.
Diem
S
S
Lehrstuhl für Lebensmittelchemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Bergmann
J
J
Herderich
M
M
D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry*; D005960:Glucosides / Q000032:analysis*; D013058:Mass Spectrometry; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000032:analysis
D005960:Glucosides; C416666:tryptophan N-glucoside; D014364:Tryptophan