Protective effect of quaternary piperidinium salts on lipid oxidation in the erythrocyte membrane

A new series of amphiphilic compounds with incorporated antioxidant functio nal group has been investigated. Piperidinium bromides, differing in the al kyl chain length (8, 10, 12, 14 and 16 carbon atoms in the chain) were synt hesised to protect biological and/or model membranes against peroxidation a nd following negative consequences. Their antioxidant activity was studied with erythrocytes subjected to UV radiation. The salts used inhibited lipid oxidation in the erythrocyte membrane. The degree of this inhibition depen ded on the alkyl chain length of the bromide used and increased with increa sing alkyl chain length. A comparison of the results obtained for piperidin ium bromides with those obtained for the widely used antioxidant 3,5-di-t-b utyl-4-hydroxytoluene (BHT) revealed that only two shortest alkyl chain sal ts were less efficient than BHT in protecting erythrocyte membranes. A simi lar comparison with antioxidant efficiency of flavonoids extracted from Ros a rugosa showed that they protected the membranes studied more weakly than the least effective eight-carbon alkyl chain piperidinium bromide. The thre e compounds of longest alkyl chains were the most active antioxidants. Thei r activities did not differ significantly.