Publications by authors named "Stanislaw Witek"

Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability.

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This work contains the results of studies on the influence of newly synthesized lysosomotropic substances (lysosomotropes) on human erythrocytes. Six homologous series of the compounds differing in the alkyl chain length and counterions were studied. They were found to hemolyse erythrocytes and to change their osmotic resistance.

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A set of oxalates of alpha-dimethylamino fatty acids n-alkyl esters (MEM-ns and n-MEM-8s) and n-dodecyl-N,N-dimethylalaninate (DMAL-12s) were synthesized. Their activities on the growth, transport, and ATPases from the yeast Saccharomyces cerevisiae were compared. The compounds differ in the number of carbon atoms in their aliphatic chain and in the position of that chain in their molecular structure.

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The lysosomotropic action of the compounds DM-11 and DMAL-12s against Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans is species- and pH-dependent. At pH 6.0, DMAL-12s is less effective against S.

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Quinacrine was used to visualize the intracellular pH changes in the yeast strain Saccharomyces cerevisiae RXII occurring after exposure to four recently-synthesized lysosomotropic drugs: DM-11, PY-11, PYG-12s and DMAL-12s. The cells took up quinacrine, mostly accumulating it in their vacuoles. DM-11 and PY-11 gave rise to diffuse quinacrine fluorescence throughout the cells, with the vacuoles staining to a somewhat greater extent than the cytosol.

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A set of n-alkyl esters of N,N-dimethylglycine (DMG-n) and their methobromides (DMGM-n) was synthesized, and their activities on yeast Saccharomyces cerevisiae were compared. The compounds differ in the number of carbon atoms in the aliphatic chain. Aminoesters with 12 carbon atoms appeared to be most active.

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