Related Experiment Video
Updated: May 27, 2026

A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
Towards a modern definition of vitamin E-evidence for a quinone hypothesis
William D Shrader1, Akiko Amagata, Adam Barnes
1Edison Pharmaceuticals, Inc., 350 North Bernardo Avenue, Mountain View, CA 94043, USA. bshrader@edisonpharma.com
Abstract:
We report on the synthesis, biological and pharmacological activity of the tocoquinone natural product, α-tocopherol quinone (ATQ); an oxidative metabolite of α-tocopherol. ATQ is a potent cellular protectant against oxidative stress, whose biological activity is dependent upon its ability to undergo reversible two-electron redox cycling. ATQ is orally bioavailable, with a favorable pharmacokinetic profile and has demonstrated a beneficial clinical response in patients with Friedreich's ataxia. ATQ is a member of a broader class of vitamin E derived quinone metabolites which may be ascribable in whole or in part to the activity of vitamin E.
Related Concept Videos
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Role of Reduced Coenzymes NADH and FADH₂
Vitamins
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
Oxidation and Reduction of Organic Molecules
The removal of an electron from a molecule, results in a...
Lipid-derived Compounds in the Human Body
Fat-soluble Vitamins
Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin, delayed...
