What is "ubiquinol"

n. (context biochemistry English) A certain benzoquinol, the reduced product of ubiquinone, also called coenzyme Q₁₀.

Ubiquinol is an electron-rich (reduced) form of coenzyme Q.

The natural ubiquinol form of coenzyme Q is 2,3-dimethoxy-5-methyl-6-poly prenyl-1,4-benzoquinol, where the polyprenylated side-chain is 9-10 units long in mammals. Coenzyme Q (CoQ) exists in three redox states, fully oxidized ( ubiquinone), partially reduced ( semiquinone or ubisemiquinone), and fully reduced (ubiquinol). The redox functions of ubiquinol in cellular energy production and antioxidant protection are based on the ability to exchange two electrons in a redox cycle between ubiquinol (reduced) and the ubiquinone (oxidized) form.