Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-5-3
pubmed:abstractText
Little is known of the post-absorptive, metabolic fate of gamma-tocopherol, the major form of vitamin E in North American diets. The objective of this study was to determine the extent of urinary excretion of 2,7, 8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC), a recently identified metabolite of gamma-tocopherol. A method for measurement of urinary gamma-CEHC was developed, using gas chromatography-mass spectrometry (GC-MS) with a deuterated internal standard, 2,7,8-trimethyl-2-(beta-carboxyethyl)-(3, 4-2H2)-6-hydroxychroman (d2-gamma-CEHC). This standard was synthesized by dehydrogenation of 6-acetyl-gamma-CEHC followed by deuteration of the resulting 3,4-double bond. The use of d2-gamma-CEHC resulted in accurate determinations of the concentration of d0-gamma-CEHC in human urine. Urine samples containing added d2-gamma-CEHC were treated with beta-glucuronidase, extracted with an organic solvent, and analyzed by GC-MS. Analysis of 24-h urine pools from healthy subjects revealed gamma-CEHC concentrations, normalized against creatinine, ranging from 2.5 to 31.5 micromol/g creatinine, or a total of 4.6 to 29.8 micromol per day. These results correspond to 2-12 mg gamma-tocopherol excreted daily as gamma-CEHC in the urine. Given an estimated mean intake of gamma-tocopherol of 20 mg/day, catabolism of gamma-tocopherol to gamma-CEHC, followed by glucuronide conjugation and urinary excretion, is a major pathway for elimination of gamma-tocopherol in humans.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
665-71
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Urinary excretion of 2,7, 8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman is a major route of elimination of gamma-tocopherol in humans.
pubmed:affiliation
Division of Nutritional Sciences, National Research Council, Ottawa, Ontario, Canada K1A 0R6.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.