Effect of electrolyte pH on CIEF with narrow pH range ampholytes.

CIEF of components following sequential injection of ampholytes and the sample zone offers unique advantages for analysis. The most important one of these is the efficient separation of amphoteric compounds having pIs outside the pH range of the ampholytes applied, but the resolution of the components can be increased by an adequate setup in the injection protocol. In this study, the effect of the pH of the anolyte and catholyte on the selectivity and speed of the isoelectric focusing was investigated. Changes in the pH values significantly influenced the resolution and the length of the pH gradient, while changes in the charge state of components were also observed. Three ampholyte solutions (from different suppliers) covering only two pH units were used for the analyses of substituted nitrophenol dyes in uncoated capillary. With appropriate setup, the components, with pIs not covered by the ampholyte pH range, migrated in charged state outside the pH gradient. This phenomenon is preferable for coupling isoelectric focusing to MS detection, by evading the undesirable ion suppression effect of ampholytes.

Preparation and investigation of bioactive transferrin-iron complexes formed with different synergistic anions.

Human serum transferrin has a potential for drug-delivery systems. Oxalate and aziridine-carboxylate was conjugated to serum transferrin in order to transport into the targeted cancer cells via transferrin-receptor mediated endocytosis. Capillary zone electrophoresis and capillary isoelectric focusing were used to analyze the effectiveness of complexation reactions. The electropherograms show the differences between iron-free- and iron-complexed molecular forms of human serum transferrin. The iron-complexed transferrin sample containing the different anions as synergistic complexing agents were characterized by different electrophoretic parameters.

Aurothiomalate as preventive and chain-breaking antioxidant in radical degradation of high-molar-mass hyaluronan.

The potential anti- or pro-oxidative effects of a disease-modifying antirheumatic drug, aurothiomalate, to protect high-molar-mass hyaluronan against radical degradation were investigated along with L-glutathione - tested in similar functions. Hyaluronan degradation was induced by the oxidative system Cu(II) plus ascorbate known as the Weissberger's oxidative system. The time- and dose-dependent changes of the dynamic viscosity of the hyaluronan solutions were studied by the method of rotational viscometry. Additionally, the antioxidative activity of aurothiomalate expressed as a radical-scavenging capacity based on a decolorization 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay was inspected. At the higher concentrations tested, L-glutathione showed excellent scavenging of (.) OH and peroxyl-type radicals, however, at the lowest concentration applied, its pro-oxidative effect was revealed. The effects of aurothiomalate on hyaluronan degradation were similar to that of L-glutathione, however, at the lowest concentration tested, no significant pro-oxidant effect was observed.