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The red clover isoflavone irilone is largely resistant to degradation by the human gut microbiota
Author(s) -
Braune Annett,
Maul Ronald,
Schebb Nils Helge,
Kulling Sabine E.,
Blaut Michael
Publication year - 2010
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.200900233
Subject(s) - genistein , human feces , daidzein , metabolite , bioavailability , eubacterium , isoflavones , biology , gut flora , biochanin a , biotransformation , flavonoid , bacteria , food science , microbiology and biotechnology , chemistry , feces , biochemistry , enzyme , pharmacology , endocrinology , genetics , antioxidant
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.