Wyniki wyszukiwania - Biblioteka Nauki

1

The interactions of phenyltin compounds with model membranes in the presence of surfactants

100%

Rozycka-Roszyk B. , Pruchnik H.

Cellular and Molecular Biology Letters

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2001

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tom 06

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nr 2A

423

2

Oddziaływanie halogenków dodecylotrimetyloamoniowych z liposomami lecytynowymi lecytynowo-cholesterolowymi.

80%

Różycka-Roszak B. , Pruchnik H. , Mucha A.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2000

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tom Vol. 48, nr 22

233-236

PL

Przedstawiono wyniki badań oddziaływania chlorku dodecylotrimetyloamoniowego (DTAC), bromku dodecylotrimetyloamoniowego (DTAB) i jodku dodecylotrimetyloamoniowego (DTAI) z liposomami lecytynowymi i lecytynowo-cholesterolowymi. Badania miały na celu przyczynić się do wyjaśnienia roli przeciwjonów w biologicznej aktywności związków amfifilowych. Aby uwypuklić znaczenie wpływu przeciwjonów na strukturę wody, surfaktanty dodawano bądź do fazy wodnej (I metoda), bądź do fazy lipidowej (II metoda). Zastosowano metodę DSC i 'H NMR. Gdy związki dodawane były do fazy wodnej to w liposomach lecytynowych i w liposomach lecytynowo-cholesterolowych powstawały domeny z dużą i małą zawartością surfaktantów. Powstawanie domen spowodowane było oddziaływaniami typu jon-woda. Natomiast, gdy surfaktanty dodawane były do fazy lipidowej liposomów lecytynowo-cholesterolowych zaznaczył się duży udział oddziaływań typu cholesterol - surfaktant.

EN

Effects of dodecyltrimethylammonium chloride (DTAC), dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermotropic phase behaviour of phosphatidylcholine bilayers and phosphatidylcholine bilayers containing cholesterol as well as on 'H NMR spectra were studied. In order to enhance the effect of counterion on water structure two series of experiments were performed. In the first one the surfactants were added to the water phase while in the other directly to the lipid phase (a mixed film from surfactant and phosphatidylcholine with or without cholesterol was formed). In the presence of cholesterol, the effects of particular surfactants ox the main phase transition temperature, Tm, were more pronounced when added to the lipid phase (II method) than to the water phase (I method); the opposite happened when cholesterol was absent .Likely, due to water-ion interactions surfactant poor and surfactant rich domains are formed when surfactants are added to the water phase.

3

Interaction of selected anthocyanins with erythrocytes and liposome membranes

80%

Bonarska-Kujawa D. , Pruchnik H. , Kleszczynska H.

Cellular and Molecular Biology Letters

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2012

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tom 17

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nr 2

EN

Anthocyanins are one of the main flavonoid groups. They are responsible for, e.g., the color of plants and have antioxidant features and a wide spectrum of medical activity. The subject of the study was the following compounds that belong to the anthocyanins and which can be found, e.g., in strawberries and chokeberries: callistephin chloride (pelargonidin-3-O-glucoside chloride) and ideain chloride (cyanidin-3-O-galactoside chloride). The aim of the study was to determine the compounds’ antioxidant activity towards the erythrocyte membrane and changes incurred by the tested anthocyanins in the lipid phase of the erythrocyte membrane, in liposomes composed of erythrocyte lipids and in DPPC, DPPC/cholesterol and egg lecithin liposomes. In particular, we studied the effect of the two selected anthocyanins on red blood cell morphology, on packing order in the lipid hydrophilic phase, on fluidity of the hydrophobic phase, as well as on the temperature of phase transition in DPPC and DPPC/cholesterol liposomes. Fluorimetry with the Laurdan and Prodan probes indicated increased packing density in the hydrophilic phase of the membrane in the presence of anthocyanins. Using the fluorescence probes DPH and TMA-DPH, no effect was noted inside the hydrophobic phase of the membrane, as the lipid bilayer fluidity was not modified. The compounds slightly lowered the phase transition temperature of phosphatidylcholine liposomes. The study has shown that both anthocyanins are incorporated into the outer region of the erythrocyte membrane, affecting its shape and lipid packing order, which is reflected in the increasing number of echinocytes. The investigation proved that the compounds penetrate only the outer part of the external lipid layer of liposomes composed of erythrocyte lipids, DPPC, DPPC/cholesterol and egg lecithin lipids, changing its packing order. Fluorimetry studies with DPH-PA proved that the tested anthocyanins are very effective antioxidants. The antioxidant activity of the compounds was comparable with the activity of Trolox®.

4

The effect of some phenyltin compounds on thermotropic behaviour of mixed phosphatidylcholine-cholesterol bilayers

80%

Rozycka-Roszak B. , Pruchnik H. , Kaminski E.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 2

5

Biological and antioxidative efficiency of some pyrrolidinium salts

70%

Kleszczynska H. , Sarapuk J. , Bielecki K. , Bonarska-Kujawa D. , Pruchnik H.

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tom 17

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nr 4

509-513

EN

A series of new pyrrolidinium salts (PYE-n) was synthesized for potential application in agrochemistry. They differed in the number of carbon atoms in the alkyl chain (n = 7, 9, 11, 13 and 15). These salts may also be used as effective antioxidants since they include a substituted free radical scavenging group. The aim of these studies was to determine the concentration level at which PYE-n can be possibly used as biocides and to examine their antioxidative capacities. Biocidal activity was determined by measuring PYE abilities to hemolyze pig erythrocytes, to influence cucumber (Cucumis sativus) growth and its membrane properties, and to influence the main transition temperature of DPPC liposomes. Measurements of fluidity changes in the ghost erythrocyte membrane induced by PYE compounds were also done. Three probes: DPH, TMA-DPH and laurdan were used in the measurements. The results of those experiments showed that the pyrrolidinium salts studied exhibit fairly good membrane activity, which makes them potentially useful agrochemical agents. Antioxidative capacity of PYE-n was determined by measuring the inhibition of the autooxidation of linoleic acid, tested in radical chromogen ABTS•+ cation decolorization assay, and by measuring the protection of erythrocyte membrane lipids against UV irradiation. All the methods used to check the potential antioxidative properties of PYEs showed that they can be used as very good free radical scavengers.

6

Interaction between polyphenol compounds of bilberry fruit extracts and model lipid membranes

70%

Pruchnik H. , Bonarska-Kujawa D. , Zylka R. , Oszmianski J. , Kleszczynska H.

Current Topics in Biophysics. Supplement

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2013

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tom 36

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nr 2A: Posters

7

Antioxidative activity of some N-oxides

61%

Kleszczynska H. , Bonarska D. , Pruchnik H. , Bielecki K. , Luczynski J. , Trela Z. , Sarapuk J.

Cellular and Molecular Biology Letters

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2005

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tom 10

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nr Suppl.