The C-glycosyl flavonoid, aspalathin, is absorbed, methylated and glucuronidated intact in humans

Fraser L. Courts, Gary Williamson

Research output: Contribution to journalArticleResearchpeer-review

45 Citations (Scopus)


Human bioavailability of the flavonoid dihydrochalcones is little understood, and no evidence exists for C-glycosyl flavonoid absorption in humans. The present study uses catechol-O-methyltransferase to generate methylated metabolites of aspalathin (a C-glycosyl dihydrochalcone from rooibos tea). One of the methylated forms, both with and without glucuronidation, was detected using LC-MS/MS in the urine of human subjects (n = 6), demonstrating that deglycosylation is not a prerequisite for C-glycosyl flavonoid absorption. Methylation is catalysed by both intestine and liver cytosolic extracts. The results show that flavonoid C-glycosides are methylated and glucuronidated in vivo in an intact form in humans.

Original languageEnglish
Pages (from-to)1104-1111
Number of pages8
JournalMolecular Nutrition & Food Research
Issue number9
Publication statusPublished - 9 Oct 2009
Externally publishedYes


  • Absorption
  • Aspalathin
  • C-glycoside
  • Flavonoid
  • Methylation

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