Jump to content

Semiquinone

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Project Osprey (talk | contribs) at 13:26, 8 September 2022. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Resonance isomers of a semiquinone

Semiquinone (or ubisemiquinone) is a free radical resulting from the removal of one hydrogen atom with its electron during the process of dehydrogenation of a hydroquinone, such as hydroquinone itself or catechol, to a quinone or alternatively the addition of a single H atom to a quinone.[1] It is highly unstable.

It is the first of two stages in reducing the supplementary form of CoQ10 ubiquinone to the active form ubiquinol.

References

  1. ^ Song, Y; Buettner, GR (Sep 15, 2010). "Thermodynamic and kinetic considerations for the reaction of semiquinone radicals to form superoxide and hydrogen peroxide". Free Radical Biology & Medicine. 49 (6): 919–62. doi:10.1016/j.freeradbiomed.2010.05.009. PMC 2936108. PMID 20493944.