Open AccessBiotransformation of the isoflavonoids biochanin A, formononetin, and glycitein by Eubacterium limosum
Author(s) -
Hur HorGil,
Rafii Fatemeh
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09353.x
Subject(s) - formononetin , biochanin a , glycitein , daidzein , eubacterium , genistein , chemistry , chromatography , metabolite , demethylation , glucuronidation , biochemistry , food science , biology , enzyme , bacteria , genetics , gene expression , microsome , gene , dna methylation , endocrinology
Eubacterium limosum (ATCC 8486), a strict anaerobe from the human intestinal tract that is capable of O ‐demethylation of several compounds, was tested for the ability to metabolize three methoxylated isoflavonoids, biochanin A, formononetin, and glycitein. High‐performance liquid chromatography elution profiles of metabolites produced from biochanin A, formononetin, and glycitein showed peaks that had identical retention times to authentic genistein, daidzein, and 6,7,4′‐trihydroxyisoflavone, respectively. The metabolites were identified, using an on line liquid chromatography‐electrospray mass spectrometer. E. limosum produced 61.4 μM of genistein and 13.2 μM of daidzein from 100 μM of biochanin A and formononetin, after 26 days incubation. O ‐demethylase activity is cell‐associated and was not detected in the extracellular fraction of bacterial culture. This is the first study in which conversion of biochanin A, and formononetin to more potent phytoestrogens by a bacterium has been shown.