Quinones and quinols as inhibitors of lipid peroxidation.

The influence of biological quinonoid compounds upon oxidative polymerization of lipids has been compared with that of simple quinones and antioxidants. A new procedure for the accelerated production and measurement of oxidative polymerization was used for this comparison. The biological quinones were found to be relatively ineffective as retarders of oxidative polymerization. Heme-catalyzed lipid peroxidation, as measured by oxygen uptake, was inhibited by ubiquinone and ubiquinol, both having about one fourth of the antioxidant capacity ofa-tocopherol. The peroxidation of mitochondrial lipid in vitro was inhibited by the presence of exogenous ubiquinone indicating that this compound may contribute towards the protection of the organelle in vivo.