Ubiquinol-10 is an effective lipid-soluble antioxidant at physiological concentrations

Proc Natl Acad Sci U S A. 1990 Jun;87(12):4879-83. doi: 10.1073/pnas.87.12.4879.


It is well known that ubiquinone-10 (coenzyme Q10, ubiquinone 50) acts as an electron carrier of the respiratory chain in mitochondria. In this paper we show that ubiquinol-10, the reduced form of ubiquinone-10, also efficiently scavenges free radicals generated chemically within liposomal membranes. Ubiquinol-10 is about as effective in preventing peroxidative damage to lipids as alpha-tocopherol, which is considered the best lipid-soluble antioxidant in humans. The number of radicals scavenged by each molecule of ubiquinol-10 is 1.1 under our experimental conditions. In contrast to alpha-tocopherol, ubiquinol-10 is not recycled by ascorbate. However, it is known that ubiquinol-10 can be recycled by electron transport carriers present in various biomembranes and possibly by some enzymes. We also show that ubiquinol-10 spares alpha-tocopherol when both antioxidants are present in the same liposomal membranes and that ubiquinol-10, like alpha-tocopherol, does not interact with reduced glutathione. Our data together with previous work on the antioxidant function of ubiquinol reported in the literature strongly suggest that ubiquinol-10 is an important physiological lipid-soluble antioxidant.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Kinetics
  • Lipid Peroxidation
  • Liposomes*
  • Phosphatidylcholines*
  • Solubility
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / chemical synthesis
  • Vitamin E


  • Liposomes
  • Phosphatidylcholines
  • Ubiquinone
  • Vitamin E
  • ubiquinol-10
  • Ubiquinone Q2
  • ubiquinol