Wyniki wyszukiwania - Biblioteka Nauki

1

Blony modelowe jako narzedzie testowania aktywnosci biologicznej substancji powierzchniowo czynnych

100%

Sarapuk J.

Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Rozprawy

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1997

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tom 149

1-96

2

Interaction of some quaternary ammonium salts with BLMs

75%

Sarapuk J.

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1990

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tom 10

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nr 2

3

Nowe spojrzenie na dwuwarstwe lipidowa

63%

Langner M. , Sarapuk J.

|

1997

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tom 70

137-158

4

Membrane-active aminophosphonates

63%

Dziamska A. , Sarapuk J.

|

tom 07

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nr 2

5

Cut-off phenomenon

63%

Sarapuk J. , Kubica K.

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nr 3

EN

The change of biological activity of amphiphilic biocides following the change of their hydrophobic parts (the cut-off effect) is discussed. The mechanism of the interaction (between such amphiphiles and model and biological membranes is proposed that explains the cut-off phenomenon. It is proposed, on the basis of experimental studies and theoretical calculations, that the diminished biological activity of amphiphilic compounds upon elongation of thier hydrophobic part can be the result of the appearance of interdigitated structures in the lipid bilayers. On the other hand, weak hydrophobic interactions between amphiphilic compounds of short hydrophobic chins and lipid molecules of model membranes are responsible for the poor biological activity of these compounds.

6

The hemolytic toxicity of some new aminophosphonates

51%

Kleszczynska H. , Sarapuk J. , Bonarska D.

Cellular and Molecular Biology Letters

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2001

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tom 06

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nr 2A

271-275

7

Structure-dependent phytotoxicity of new aminophosphonates

51%

Bielecki K. , Dziamska A. , Sarapuk J.

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2002

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tom 481

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nr 1

EN

Electrolyte efflux, chlorophyll, malondialdehyde content and enzymatic activities (catalase, peroxidase) in cucumber cotyledons as well as stability of model lipid membranes in the presence of some new, acyclic and cyclic, aminophosphonates were studied. They also differed in the substituents at the phosphorus and nitrogen atoms. It was found that the effectiveness of the compounds to influence mentioned parameters depended on their lipophilicity and structural features. The most active compounds were these with isopropyl substituents at the P atom unless their hydrocarbon chains at the N atom were not too long. Butyl substituents at phosphorus significantly decreased aminophosphonates efficiency. Similar effect was observed when trans-type hydrocarbon chain was replaced with a short-branched one. It also seems that cyclic compounds with hexane rings were weaker modifiers of model and biological membranes than these with pentane rings. Results show that aminophosphonates interact with plasma membranes and presumably induce oxidative stress.

PL

Badano wpływ nowych cyklicznych i acyklicznych aminofosfonianów na zawartość chlorofilu, dialdehydu malonowego oraz aktywność enzymów (katalaza, peroksydaza) w liścieniach ogórka. Określono efekt działania związków na stabilność modelowych błon lipidowych i wypływ elektrolitów z tkanki roślinnej. Badane aminofosfoniany różniły się ponadto podstawnikami przy atomie fosforu i azotu. Stwierdzono, że efektywność działania związków zależała od ich lipofilowości i kształtu cząsteczki. Najbardziej aktywne aminofosfoniany zawierały podstawnik izopropylowy przy atomie fosforu oraz niezbyt długi łańcuch węglowodorowy przy atomie azotu. Podstawnik butylowy przy atomie fosforu istotnie obniżał efektywność działania aminofosfonianów. Wydaje się, że cykliczne związki z pierścieniem cykloheksanowym w słabszym stopniu wpływają na membrany biologiczne i modelowe w porównaniu do związków zawierających cyklopentan. Wyniki badań wskazują, że aminofosfoniany oddziałują na membrany plazmatyczne i przypuszczalnie indukują stres oksydacyjny.

8

New aminophosphates - mechanism of action

51%

Bielecki K. , Dziamska A. , Sarapuk J.

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nr 3 suppl.

9

Antioxidative activity of pirolidinium salts in the erythrocyte membrane

51%

Kleszczynska H. , Sarapuk J. , Oswiecimska M. , Witek S.

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2000

|

tom 09

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nr 6

475-478

EN

The antioxidant activity of two new series of pirolidinium chlorides (PAC-n) and bromides (PAB-n) was studied. The antioxidant functional group was incorporated into the polar part of the compounds. The influence of the compounds on the degree of lipid oxidation in the erythrocyte membrane subjected to UV radiation was studied. It was found that all the salts used protected erythrocyte membranes against oxidation of membrane lipids. Their antioxidant activity increased with alkyl chain length. PAB compounds were stronger oxidation inhibitors than PAC ones. Possible reasons for such behaviour are discussed, taking into account the fluidity changes in erythrocyte membrane caused by the compounds studied. In order to do this, steady-state measurements of fluorescence anisotropy were performed, enabling to calculate the anisotropy coefficient.

10

The physicochemical properties of some new aminophosphonates

51%

Kleszczynska H. , Sarapuk J. , Dziamska A.

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tom 05

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nr 4

415-422

EN

The hemolytic activity of some newly synthesized aminomethanephosphonic acid derivatives was studied. The compounds studied differed in their polarity and the hydrophobicity of the electronic substituents at their nitrogen and carbon atoms. It was found that acyclic aminophosphonates exhibited significantly stronger hemolytic properties than cyclic aminophosphonates. To cause the same level of hemolysis of pig erythrocytes, it was necessary to use about a tenfold higher concentration of cyclic aminophosphonates than acyclic ones. The hemolytic activities of the compounds were related to the possibilities of their incorporation into the lipid phase of erythrocyte membranes. Once incorporated, they changed the fluidity of those membranes; the changes were more pronounced in the case of cyclic aminophosphonates. Acyclic compounds were also found to exhibit a slight antioxidative activity, which may be a consequence of their stronger interaction with the membrane lipids. The results obtained in the experiments performed with the use of planar lipid membranes were similar to those obtained in the hemolytic studies, i.e., acyclic aminophosphonates interacted more effectively with those membranes. The general conclusion is that both stereochemistry and hydrophobicity are the factors that determine the efficiency of the interaction of the compounds studied with the model membranes used, and that most likely location of aminophosphonates is the lipid phase of the erythrocyte membrane. Another conclusion is that newly synthesized aminophosphonates may be used as potentially good pesticides.

11

New aminophosphonates - estimation of their potential pesticidal efficiency

51%

Dziamska A. , Bielecki K. , Kleszczynska H. , Sarapuk J.

|

2001

|

tom 12

219-226

12

Influence of some acyclic aminephosphonates on hemolysis of red cells and stability of planar lipid membranes

51%

Dziamska A. , Sarapuk J. , Kleszczyńska H.

|

tom Vol. 48, nr 22

189-192

EN

The interaction of some derivatives of aminemethane phosphonic acid with erythrocytes (RBC) and planar lipid membranes (BLM) was studied. Aminephosphonates were synthesized to be used as pesticides and differed in their polarity and hydrophobicity of the substituents on nitrogen and phosphorus atoms. Their structural features should enable them to interact with the lipid phase of biological objects. That was the reason to make introductory evaluation of their potential biological activity by studying on their interaction with mentioned models. We investigated the influence of aminephosphonates on stability of BLM and hemolysis of RBC. The measured parameters were so-called critical concentration (CC) of the compounds causing destruction of BLM in arbitrarily chosen time of 3 min, and causing 100% hemolysis of RBC (C100). Additionally the fluorescence spectroscopy method was used to follow changes in fluidity of erythrocyte ghosts cased by the compounds studied. The measured parameter was the anisotropy coefficient (A). It was found that all the compounds studied exhibited good enough efficiency to destroy model membrane studied to classify them as potentially good pesticides. The observed differences in the interaction with membranes used may be attributed to structural differences between the aminephosphonates and the resulting differences in lipophilicity.

PL

Zbadano oddziaływanie nowo zsyntetyzowanych związków fosforoorganicznych z błonami erytrocytów i płaskimi błonami lipidowymi. Badane aminofosfoniany były zróżnicowane hydrofobowo Celem pracy było znalezienie wpływu tego zróżnicowania na efektywność oddziaływania związków z błonami modelowymi. Wybór tych ostatnich uzasadniają wcześniejsze badania, w których wykazano ich przydatność do wstępnego, szybkiego testowania związków syntetyzowanych z myślą o ich biologicznym zastosowaniu. Badanymi parametrami były stężenia aminofosfonianów powodujących całkowitą dezintegrację błon modelowych tzn. 100% hemolizę erytrocytów lub niszczenie błon lipidowych w określonym arbitralnie czasie. Ponadto, celem -wyjaśnienia mechanizmu oddziaływania aminofosfonianów na błony modelowe, wykonano metodą spektroskopii fluorescencyjnej pomiary zmian ciekłości błon cieni erytrocytów przy pomocy dwu sond fluorescencyjnych zlokalizowanych na różnych głębokościach fazy lipidowej błony. Otrzymane wyniki wskazują, że badaną grupę aminofosfonianów można zaliczyć do pestycydów o potencjalnie dobrej skuteczności biologicznej.

13

Hemolytic and physiological activity of new synthesized aminephosphonates

51%

Dziamska A. , Sarapuk J. , Kleszczyńska H. , Bielecki K.

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tom Vol. 48, nr 22

193-196

EN

Some new, synthesized cyclic and acyclic aminephosphonates were studied. Two model membranes were used in order to determine potential biological activity of those compounds. They were erythrocytes (RBC) and planar lipid membranes (BLM). The choice of the model membranes was justified by earlier studies on determination of potential biological usefulness of several quaternary ammonium salts. It was found that the -models used were very convenient tools for preliminary estimation of this type of compounds, which because of their hydrophobicity readily interact with lipid model membranes or the lipid phase of biological membranes. Moreover, a very high qualitative agreement was found between the results of model and biological experiments. Measurements performed permitted the determination of concentrations of the compounds musing total destruction of RBC (100% hemolysis - C100) or BLM in predetermined time (3 min - CC). The -results obtained was then compared with the results of biological tests on the aqueous plant Spirodela oligorhiza. The parameter measured in physiological tests was concentration of the compounds causing 50% inhibition of plant growth (IC50). All experiments were also performed for two herbicides known for their physiological activities. Those were dibutyl ester of 9-(N-n-butylamine)-phosphonic acid-1 (BAPA) and diethyl ester of 9-(N-n-butylamine)fluorenephosphonic acid-9. It was found that acyclic compounds exhibited good enough efficiency to destroy model membrane studied to classify them as potentially good pesticides. The efficiency of cyclic compounds was significantly worse. The observed differences between efficacies of the compounds toward both plant and model membrane is discussed.

PL

Zbadano oddziaływanie nowo zsyntetyzowanych aminofosfonianów na błony erytrocytów, płaskie błony lipidowe i na roślinę wodną Spirodela oligorrhiza. Badane aminofosfoniany były zróżnicowane strukturalnie. Celem pracy było znalezienie wpływu tego zróżnicowania na efektywność oddziaływania związków, jego mechanizm określenie ich przydatności biologicznej. Badanymi parametrami były stężenia aminofosfonianów powodujących całkowitą dezintegrację błon modelowych oraz inhibicję wzrostu Spirodeli oligorrhizy. Otrzymane wyniki wskazują, te badaną grupę aminofosfonianów można zaliczyć do pestycydów o potencjalnie dobrej skuteczności biologicznej.

14

Time-dependent modification of model membrane properties by benzylammonium chlorides

51%

Gabrielska J. , Sarapuk J. , Kleszczynska H. , Przestalski S.

|

nr 3

EN

The nature of the interaction between some strong antifungal compounds and model membranes was studied. It was found that these compounds (N-dodecyl-N,N-dimethyl-N-/3- (β-methyl-β-nitrovinyl 1-6-methoxybenzyl/ammonium chloride and its derivatives) significantly change the properties of liposomes, planar lipid bilayers (BLM) and erythrocytes. The changes observed (i.e., release of praseodymium ions from liposomes and gradually diminished stability of BLM) in the presence of the compounds studied, as well as hemolysis of red blood cells, were time-dependent. It was also found that they depended on the polar head structure of the compounds.

15

Hemolytic and physiological activities of mixtures of organophosphorous herbicides

51%

Kleszczynska H. , Bonarska D. , Bielecki K. , Sarapuk J.

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nr Suppl.

16

Effect of some biologically active quaternary ammonium salts on planar phospholipid membranes

51%

Sarapuk J. , Gabrielska J. , Przestalski S.

Polish Journal of Environmental Studies

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1992

|

tom 01

|

nr 1

EN

The effect of some biologically active amphilic quaternary ammonium chlorides (QA) on properties of bimolecular planar membranes (BLM) formed of lipids extracted from bovine erythrocytes was studied. Ammonium salts differed in the alkyl chain length or in the non-methylene group incorporated between the hydrocarbon chain and the polar head of a molecule. It was found that in the case of a series of QA of general structure (CH3)3N+CH2OCnH2n+1 (n=4, 10, 12, 14, 16 and 18) there exists a maximal interaction between QA and BLM for QA with n=16. It was also found that the introduction of different functional groups, between the nitrogen atom and the alkyl chain of the molecule significantly changed the interaction between ammonium salts and lipid membranes. The observed changes are explained in terms of changed amphiphilic properties of the molecule.

17

Modification of mechanical properties of model membranes by some bifunctional surfactants

51%

Kleszczynska H. , Sarapuk J. , Rozycka-Roszak B.

|

nr 1

EN

The interaction of two series of new surfactants with an incorporated anti-oxidant functional group, with erythrocytes and planar lipid membranes was stu-died. The surfactants were synthesized to be potentially used as common bio-cides or as agents protecting biological and/or model membranes against lipid peroxidation. Both applications need the use of such bifunctional surfactants in significantly different concentrations. The aim of this work was to find the concentration range in which the surfactants studied could be used as biocides. Two different models were chosen; pig erythrocyte and asolectin planar membranes. The studied parameters of these models were hemolysis of red blood cells and the stability of BLM in the presence of the compounds studied, i.e., the parameters describing the mechanical properties of the model membranes used. Additionally, the role of counterions in the interaction of bifunctional surfactants with model membranes was studied. It was found that both homologous series of the surfactants influence model membranes to different degrees, depending on the length of their hydrophobic part and the kind of counterion. In the latter case it seems that the differences in the hydrated radii of bromide and chloride ions, and hence the differences in their ability to modify electrostatic interaction between the lipid polar heads and compounds studied, are responsible for the effects observed.

18

Potential pesticide efficiency of new bifunctional surfactants

51%

Sarapuk J. , Kleszczynska H. , Radecka H. , Oswiecimska M.

|

tom 05

|

nr 3

EN

Two series of new bifunctional surfactants were synthesized for potential use as antioxidants or as pesticides, depending on their concentration. At a low concentration, the surfactants can be incorporated into the membranes with no damage to these membranes, while surfactants antioxidant functional group, localized in its polar part, protrudes outside thus effectively protecting the membranes. If the concentration of the incorporated surfactant is high enough it can destroy membranes acting as a common biocide. The aim of this paper was to determine the concentration level at which surfactants can be possibly used as biocides. The surfactants studied differed in the polar head and/or in the length of their alkyl chain. One of the investigated series consisted of pyrolidinium chlorides (PC), whereas the other series consisted of the respective bromides (PB). PB salts were found to be more destructive to model membranes studied (erythrocytes - RBC and planar lipid membranes - BLM) than PC salts. Also, the results of BLM experiments indicate the existence of a maximum of the interaction between planar lipid membranes and surfactants when they have about twelve carbon atoms in the alkyl chain. It may be possible that interdigitation phenomena are responsible for this effect.

19

Antioxidative activity of some phenoxy and organophosphorous compounds

51%

Bonarska D. , Kleszczynska H. , Sarapuk J.

|

tom 07

|

nr 3

EN

Experiments were performed in order to check whether biological activity of some organophosphorous compounds widely applied as herbicides: 2,4-dichlorophenoxyacetic acid (1) and its sodium salt (2), N- phosphonomethylglycine acid (3) and its sodium salt (4), diethyl 1-butylamino- l-cyclohexanephosphonate (5) and diethyl 9-butylamino-9-fluorenephosphonate (6) followed from their oxidative activity. The compounds studied differed in their polarity and hydrophobicity. On the contrary, it was found that all herbicides protected erythrocyte membranes against partial peroxidation induced by UV irradiation. The effect was somewhat differentiated and followed the sequence: 5>1>2>6>3>4. The observed differences between the antioxidative activities of the compounds are probably related to differences in their ability to incorporate into the lipid phase of the erythrocyte membrane. Once incorporated, they change fluidity of the membranes. The extent of the changes was determined in fluorescence measurements. Polarization and anisotropy coefficients of erythrocyte membranes modified by micromolar concentrations of herbicides at different temperatures were measured for that purpose. Generally, they followed the sequence found for antioxidative activity of the herbicides studied, which confirms the assumption of close correlation between the depth of incorporation of a herbicide into the erythrocyte membrane and its protective efficiency.

20

The hemolytic and physiological activities of mixtures of some phenoxy and organophosphorous herbicides

51%

Kleszczynska H. , Bonarska D. , Bielecki K. , Sarapuk J.

|

2003

|

tom 08

|

nr 1

EN

Experiments were performed investigating the potential to improve the biological activity of some phenoxy and organophosphorous compounds by using them in binary mixtures. The compounds were: 2,4-dichlorophenoxyacetic acid (1) and its sodium salt (2), dibutyl 1-butylamino-l-cyclohexanephosphonate (3) and diethyl 9-butylamino-9-fluorenephosphonate (4), all widely used as herbicides. There were two test methods: the inhibition of cucumber (Cucumis sativus) growth induced by one single herbicide or by equimolar binary mixtures of herbicides; and, in parallel, the hemolytic efficiency of separate compounds or their mixtures. The hemolytic properties of the compounds were studied as hemolysis is generally a good measure of their toxicity, especially in the case of lipophilic compounds. Pig erythrocytes were used as good models for the determination of toxicity and the kinetics of red blood cell hemolysis. In the plant-based experiments, binary mixtures were found to display additive type toxicity. The compounds’ hemolytic activities were of additive or antagonistic types. In some combinations, the addition of a second component did not change the hemolytic efficiency of the first component, and vice versa.