The red clover isoflavone irilone is largely resistant to degradation by the human gut microbiota
✍ Scribed by Annett Braune; Ronald Maul; Nils Helge Schebb; Sabine E. Kulling; Michael Blaut
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 303 KB
- Volume
- 54
- Category
- Article
- ISSN
- 1613-4125
No coin nor oath required. For personal study only.
✦ Synopsis
Intestinal bacteria may influence bioavailability and physiological activity of dietary isoflavones. We therefore investigated the ability of human intestinal microbiota to convert irilone and genistein in vitro. In contrast to genistein, irilone was largely resistant to transformation by fecal slurries of ten human subjects. The fecal microbiota converted genistein to dihydrogenistein, 6'-hydroxy-O-desmethylangolensin, and 2-(4-hydroxyphenyl)-propionic acid. However, considerable interindividual differences in the rate of genistein degradation and the pattern of metabolites formed from genistein were observed. Only one metabolite, namely dihydroirilone, was formed from irilone in minor amounts. In further experiments, Eubacterium ramulus, a prevalent flavonoid-degrading species of the human gut, was tested for transformation of irilone. In contrast to genistein, irilone was not converted by E. ramulus. Irilone only differs from genistein by a methylenedioxy group attached to the A-ring of the isoflavone skeleton. This substitution obviously restricts the degradability of irilone by human intestinal bacteria.