Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Suppl
pubmed:dateCreated
1999-1-6
pubmed:abstractText
We established a method for using HPLC and diode-array ultraviolet scanning to quantitate soy isoflavonoids in foods and in human plasma, urine, and breast milk. The analytes occurring as glycoside conjugates were hydrolyzed enzymatically before HPLC analysis if extracted from biological matrices or were subjected to direct HPLC analysis after extraction from foods. We monitored the isoflavones daidzein, genistein, glycitein, formononetin, and biochanin-A and their mammalian metabolites equol and O-desmethylangolensin in human plasma, urine, and breast milk. Analytes were identified by absorbance patterns, fluorometric and electrochemical detection. and comparison with internal and external standards. In addition, we identified analytes by using gas chromatography-mass spectrometry after trimethylsilylation. The HPLC method was also used to measure concentrations of isoflavones and their glucoside conjugates in various soy-based infant formulas. Total isoflavone concentrations varied between 155 and 281 mg/kg. After one woman received a moderate challenge with 20 g roasted soybeans (equivalent to 37 mg isoflavones), we detected mean total isoflavone concentrations of approximately 2.0 micromol/L in plasma, 0.2 micromol/L in breast milk, and 3.0 micromol/h in urine. According to our measurements, with adjustment for body weight, isoflavonoid exposure is 4-6 times higher in infants fed soy-based formula than in adults eating a diet rich in soyfoods (approximately 30 g/d). Implications of the presented results for the potential cancer-preventing activity of isoflavones by exposing newborn infants to these phytochemicals are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0002-9165
pubmed:author
pubmed:issnType
Print
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1466S-1473S
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Isoflavones in human breast milk and other biological fluids.
pubmed:affiliation
Cancer Research Center of Hawaii, Honolulu 96813, USA. adrian@crch.hawaii.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't