Relative antioxidant activities of the seven tocopherols

The antioxidant activities of the seven tocopherols and of the unmethylated parent compound (tocol) have been compared in several systems. The three tocopherols unsubstituted in the 5‐position (δ, γ and η) were more effective than the other four in protecting carotene in mineral oil solution at 75°. In lard esters at 90° and in methyl linoleate at 50° δ, γ, η and β were the most, and ϵ, ζ and α the least, effective, the precise order depending on the conditions and concentrations used. the tocopherols were much less effective in protecting lard esters exposed to light, δ being the best of the series.