Antioxidative activity of some quaternary ammonium salts incorporated intoerythrocyte membranes

The antioxidative activity of two series of amphiphilic compounds from a gr oup of quaternary ammonium salts has been investigated. They were so-called bifunctional surfactants synthesized to be used as common pesticides or as antioxidants. The latter application was to be ensured by providing the co mpounds studied with an antioxidant group. Studies on antioxidative possibi lities of those compounds were performed on pig erythrocytes Due to their h ydrophobic parts, they anchor in the erythrocyte membrane and influence the degree of lipid oxidation in the erythrocyte membrane subjected to UV radi ation. It was found that compounds of both series decreased the oxidation o f the membrane lipids. The inhibition of this oxidation increased with the length of their hydrophobic chains up to fourteen carbon atoms. The compoun ds of the longest hydrophobic chains showed a somewhat weaker antioxidative activity. Of the two series studied compounds were more effective having b romide ions as counterions. The corresponding compounds of a second series (chlorides) protected erythrocyte significantly weaker against oxidation. T he effect of the compounds on fluidity of the erythrocyte membrane has been studied in order to explain the oxidation results. Change in fluidity of t he erythrocyte ghost membranes was found also dependent on length of the hy drophobic part of the compounds and was more pronounced in the case of brom ide surfactants. The final conclusion is that the compounds studied can be succesfully used as antioxidant agents of good efficacy.