Tocopheryl Quinone is Converted into Vitamin E in Man

The conversion of image-tocopheryl quinone into image-tocopherol in humans has been demonstrated. A male subject was given an oral dose of 400 mg of image-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 image-[5,7-(C2H3)2]-tocopherol at a concentration of 0.4 image, representing 0.8% of the total tocopherol in the plasma sample. This experiment clearly demonstrates that orally administered image-tocopheryl quinone is converted in a low overall yield to image-tocopherol in humans. The conversion to image-tocopherol of that portion of the quinone dose which was actually absorbed into the blood stream may, however, have been fairly efficient. Copyright © 1997 Elsevier Science Inc.