Wplyw niektorych pestycydow i temperatury na budowe struktury liposomow

Studies were carried out on the effect of chloride of N-dodecyl-betaine 2-chloroethyl-ester (BE V-B), and chloride of betaine 2-chloroethyl-ester (BE V-B), added to liposomes formed of egg yolk lecithin, on the order parameter of a spin probe incorporated in the temperature range 2-50 °C. The BE’s used here modified ESR spectra to various degrees and lowered the order parameter of the spin probe. At temperatures lower than 20 °C compound V-B caused smaller changes in the order parameter than V-A, whereas above that temperature it caused greater changes. The ESR spectra of liposomes containing BE's exhibited splitting into two components that corresponded to different order parameter values. The molecular mechanism of interaction between the compounds studied and liposomes is disscused.Przeprowadzono badania nad wpływem chlorku (N-dodecylo-betaina 2-chloroetyl-ester) (BE V-A) i chlorku (betaina 2-chloroetyl-ester) (BE V-B) dodanych do liposomów otrzymanych z lecytyny żółtka jaja kurzego, na parametr uporządkowania spinów sondy (BE) wprowadzonej w zakresie temperatur 2-20ºC. BE użyte tutaj jako sonda modyfikuje spektrum ESR w różnym stopniu i obniża parametr uporządkowania spinów sondy. W temperaturach niższych od 20ºC związek V-B powodował mniejsze zmiany w parametrze uporządkowania aniżeli związek V-A, chociaż dla temperatur wyższych od 20ºC powodował on zmiany większe. Spektrum ESR liposomów zawierających (BE) wykazały rozdzielenie na dwa składniki odpowiednio związane z różnymi parametrami uporządkowania spinów. W pracy przedstawiono molekularny mechanizm współzależności pomiędzy badanymi związkami a liposomami

Interaction between model membranes and a new class of surfactants with antioxidant function.

The effect of two series of amphiphilic quaternary ammonium salts on some properties of phospholipid membranes was studied. The compounds of one series, N-benzyl-N,N-dimethyl-N-alkyl ammonium bromides, exert a destructive effect on membranes and are treated as reference compounds. The compounds of the other series, N-(3,5-di-t-butyl-4-hydroxy)benzyl-N,N-dimethyl-N-alkyl ammonium bromides, are derivatives of the former ones, exhibit antioxidant properties, and do only relatively slight damage to the membranes. The aim of the work was to explain the difference in molecular interaction with membranes between the two kinds of hydrophobic compounds. Thermodynamic methods, a new mixing technique, and monolayer and quantum calculation methods were used. It has been shown that the antioxidant molecules are less hydrophobic than those of the reference compounds and disturb the membrane organization to a lesser extent. On the basis of monolayer data, we suggest that the studied antioxidant behaves like a substitutional impurity, whereas the reference behaves like an interstitial one