title: alpha-Tocopheryl quinone is converted into vitamin E in man.
abstract: The conversion of alpha-tocopheryl quinone into alpha-tocopherol in humans has been demonstrated. A male subject was given an oral dose of 400 mg of alpha-3,5-[(C2H3)2]-tocopheryl quinone with an evening meal. Analysis of plasma 15 h later by lipid extraction and subsequent GC-MS single ion monitoring revealed the presence of alpha-[5,7-(C2H3)2]-tocopherol at a concentration of 0.4 microM, representing 0.8% of the total tocopherol in the plasma sample. This experiment clearly demonstrates that orally administered alpha-tocopheryl quinone is converted in a low overall yield to alpha-tocopherol in humans. The conversion to alpha-tocopherol of that portion of the quinone dose which was actually absorbed into the blood stream may, however, have been fairly efficient.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario, Canada.
authors.forename: A N
authors.initials: AN
authors.lastname: Moore
authors.forename: K U
authors.initials: KU
authors.lastname: Ingold
mesh_terms: D000284:Administration, Oral; D000368:Aged; D001711:Biotransformation; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D014810:Vitamin E; C002421:tocopherylquinone