Antioxidative properties of pyrrolidinium and piperidinium salts.

Two series of pyrrolidinium (PYA-n) and piperidinium (PPPA-n) bromides with incorporated antioxidant function were synthesized. Both have hydrocarbon chains with odd number of the carbon atoms (n) ranging between 7 and 15. Pig erythrocytes (RBC) were used to study antioxidant activity of these compounds.

Suppression of radical-induced lipid peroxidation in a model system by alkyl esters of cinnamate quaternary ammonium salts.

Three new groups of phenolic antioxidants, quaternary ammonium salts with a phenol ring and alkyl chains of different length (pyrrolidine ethyl esters of 3,5-di-t-butyl-4-hydroxydihydrocinnamic acid n-alkoxymethylchlorides (PYE-n) or n-alkylbromides (PYA-n) and 2-dimethylaminoethyl ester n-alkylbromides (PPA-n), were synthesized. Some of them were previously found to efficiently protect yeast cells against oxidants and to inhibit the production of thiobarbituric acid-reactive substances in whole yeast cells and in isolated membrane lipids. The new antioxidants (at 1-100 microM) abolished or diminished peroxidation of olive oil emulsions caused by the OH*-producing Fe2+ and RO* and ROO*-producing tert-butylhydroperoxide (TBHP) and the azo compounds 2,2'-azobis-(amidinopropane)dihydronitrile (AAPH) and 1,1'-azobis-(1-cyclohexanecarbonitrile) (ACHN): all present at 10 mM.

The antioxidant activity of BHT and new phenolic compounds PYA and PPA measured by chemiluminescence.

The antioxidative properties of two series of new phenolic, amphiphilic compounds were evaluated using the chemiluminescence (CL) method. 2,2'-Azobis (2-amidinopropane) dihydrochloride (AAPH) was used as a source of free radicals, to obtain high and prolonged CL. Three different kinds of buffers (organic and inorganic) were tested.

Spontaneous and radical-induced plasma membrane lipid peroxidation in differently oxidant-sensitive yeast species and its suppression by antioxidants.

Formation of thiobarbituric acid-reactive substances (TBRS; nmol/mg lipids) indicative of lipid peroxidation was measured in whole cells and in isolated plasma membrane lipids from three yeast species differing in oxidant sensitivity (Schizosaccharomyces pombe, Saccharomyces cerevisiae and Rhodotorula glutinis) after exposure to the Fenton reagent, FeII, H2O2, tert-butyl hydroperoxide (TBHP) and azo compounds (AAPH, ACHN). In whole cells, spontaneous TBRS formation rose in the sequence S. pombe < S.

New phenolic antioxidants of PYA and PYE class increase the resistance S. cerevisiae strain SP4, its SOD- and catalase-deficient mutants to lipophilic oxidants.

Was demonstrate the protection ability against reactive oxygen species afforded to S. cerevisiae (wild-type strain SP4 and its mutants deficient in major antioxidant enzymes--catalase T and A, CuZnSOD) by PYA and PYE, new groups of phenolic antioxidants (quaternary ammonium salts of dihydrocinnamic acid amino esters with different alkyl chains; synthesized in this laboratory). The survival of strains exposed to the lipophilic oxidation inducers tert-butyl hydroperoxide (TBHP) and 1,1'-azobis(4-cyclohexane carbonitrile) (ACCN) with or without antioxidant pretreatment was determined by plating.