ABSTRACT
Antioxidation activity (AOA) of ubiquinone (Q10), phylloquinone (vitamin K1), menadione as well as of the newly synthesized analogues of vitamin K1--N-derivatives of 2-methyl-3-aminomethyl 1.4-naphthoquinone, producing autocomplexes with intramolecular transfer of electrons, was studied in the model system of the methyl oleate initiated oxidation. The menadione AOA was shown to be 2-fold higher as compared with the inhibitory activity of natural quinones. Activity of AK-40 and AK-49, artificial analogues of vitamin K1, was higher 2.6-fold than that of ubiquinone and phylloquinone and 1.4-fold higher than menadione activity. At the same time, AOA of ubiquinone and phylloquinone was 1.5-fold lower than the tocopherol activity, while naphthoquinones AK-40 and AK-49 were 2-fold more active as compared with tocopherol but their activity was 2-fold lower than ionol. Mechanism of natural and synthetic quinones action as well as properties of their long chain analogues are discussed.
Subject(s)
Antioxidants/pharmacology , Quinones/pharmacology , Antioxidants/chemical synthesis , Quinones/chemical synthesis , Structure-Activity RelationshipABSTRACT
The combined action of ovarian phosphatidylcholine and phylloquinone (vitamin K1), menadione, artificial analogues of vitamin K1--N-derivatives of 2-methyl-3-aminomethyl-1,4-naphthoquinone (AK-40, AK-49) recommended as promising membrane protectors was studied. Synergic effects were detected in the antioxidant action of the quinones studied and phosphatidylcholine; AK-40 was the most effective in the presence of phosphatidylcholine. The synergic effect correlated with the concentrations of the antioxidants. Alterations in the synergism, which depended on phosphatidylcholine concentrations, were similar for all the inhibitors studied: the effect was proportionally increased with the elevation of phosphatidylcholine concentrations in the mixture up to 2.5 x 10(-3) M and then the synergic effect was unaltered during the further increase in phosphatidylcholine content.
