Identification of urinary metabolites of the red clover isoflavones formononetin and biochanin A in human subjects.
Dietary supplements manufactured from red clover are widely marketed to provide the beneficial health effects of isoflavones without changing the original diet. In this study the metabolism of formononetin and biochanin A, the principal isoflavones of red clover, was studied in human subjects. Seven women ingested four red clover dietary supplements, and the metabolites of the isoflavones were identified in their urine samples. The structures of trimethylsilyl derivatives of the metabolites were established by GC-MS. New reduced metabolites of formononetin (dihydroformononetin and angolensin) and biochanin A (dihydrobiochanin A and 6'-hydroxyangolensin) were identified in urine samples using authentic reference compounds. Possible metabolic pathways are presented for the red clover isoflavones formononetin and biochanin A.
Heinonen
Satu-Maarit
SM
Folkhälsan Research Center and Department of Clinical Chemistry, University of Helsinki, Finland. Satu-Maarit.Heinonen@helsinki.fi
Wähälä
Kristiina
K
Adlercreutz
Herman
H
D000328:Adult; D019587:Dietary Supplements; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D019833:Genistein / Q000652:urine*; D006801:Humans; D007529:Isoflavones / Q000652:urine*; D008875:Middle Aged; D029921:Trifolium / Q000737:chemistry*
D007529:Isoflavones; C007768:formononetin; D019833:Genistein; C004541:biochanin A