Metabolites of dietary atractyligenin glucosides from coffee are excreted in urine.
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Atractyligenin-19-O-β-d-glucuronide was the predominant metabolite.
Abstract
Arabica roast coffee contains a substantial amount of water soluble atractyligenin-2-O-β-d-glucoside, which is ingested by consumption of coffee brew. Metabolomics data suggest this coffee compound is excreted as glucuronides, but the structures of conjugates have not been elucidated so far. We collected coffee drinkers’ urine and isolated four metabolites by MS-guided liquid chromatographic fractionation. The structures were investigated by nuclear magnetic resonance (NMR) and time-of-flight mass spectrometry (ToF-MS) and identified as atractyligenin-19-O-β-d-glucuronide (M1), 2β-hydroxy-15-oxoatractylan-4α-carboxy-19-O-β-d-glucuronide (M2), and 2β-hydroxy-15-oxoatractylan-4α-carboxylic acid-2-O-β-d-glucuronide (M3). An unconjugated metabolite (M4) was confirmed as atractyligenin. We analyzed spot urines from n = 6 coffee drinking individuals and detected the metabolites M1, M2 and M4 in every sample, and M3 in four out of six samples, suggesting interindividual differences in metabolism.
Graphical abstract
Abbreviations
UHPLC ToF MS
Ultrahighperformance liquid chromatography Time-of-Flight mass spectrometry
NMR
Nuclear magnetic resonance
Keywords
Atractyligenin
Coffee
Metabolites
Data availability
All data are in the main manuscript and the supplemental information file.