References of "Deleu, Magali"
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See detailInteraction between the antifungal lipopeptide fengycin and lipid membrane
Deleu, Magali ULg; Nylander, Tommy

Conference (2012, August 28)

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See detailCharacterization of the interaction of xylose-based bolaamphiphiles with biomimetic membrane systems
Nasir, Mehmet Nail ULg; Legrand, Vincent; Gatard, Sylvain et al

Conference (2012, July)

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See detailUse of ionic liquids for biocatalytic synthesis of sugar derivatives
Galonde, Nadine ULg; Nott, Katherine ULg; Debuigne, Antoine ULg et al

in Journal of Chemical Technology & Biotechnology (2012), 87(4), 451-471

Sugar-based compounds are widely used in pharmaceuticals, cosmetics, detergents and food. They are mainly produced by chemical methods, but the use of enzymes as ‘a greener alternative’ to organic ... [more ▼]

Sugar-based compounds are widely used in pharmaceuticals, cosmetics, detergents and food. They are mainly produced by chemical methods, but the use of enzymes as ‘a greener alternative’ to organic synthesis has been investigated for more than 20 years. Due to the low polar substrate solubility in organic solvents compatible with enzymes, research has focused on the application of substitutes for biocatalysis, especially ionic liquids (ILs). After introducing the main properties of ILs and especially their ability to solubilize sugars, this review focuses on one of their applications, the biocatalytic synthesis of carbohydrate derivatives. In this context, they can be used in pure IL systems, in IL/IL systems or in IL/organic solvent systems. Finally, this review provides an update on the environmental fate of ILs. Their exploitation in ‘green’ processes is still limited due to their low degradability but research is currently under way to design new more ‘eco-friendly’ ILs. [less ▲]

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See detailCalcium-induced conformational changes of the elicitor and membrane-active fengycin
Nasir, Mehmet Nail ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2012, April)

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor ... [more ▼]

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor activities of other compounds. The target of the biological activities of fengycin is supposed to be plasma membrane of sensitive cells. Even though the natural fengycin from has been discovered 25 years ago, nowadays, there is an increase of interest for this compound because of its potent applications. Until 15 years ago, the primary structure of fengycin was a matter of open debate before the publication of the corrected structure obtained by nuclear magnetic resonance and mass spectroscopy techniques. Although the infrared and ultraviolet absorption spectra of the lipopeptide were measured, no detailed analysis of these data was performed probably because of the unconventional sequence of the lipopeptide making these kinds of analyses complicated. In this work, our attempt was to analyze the conformational properties of fengycin as well as the calcium-induced changes using two complementary spectroscopic methods, Fourrier transformed infrared spectroscopy (FTIR) and circular dichroism (CD). In a first step, we have characterized the conformational properties of pure fengycin. The lipopeptide adopts turn conformation in trifluoroethanol, a membrane-mimicking solvent. D-aminoacids seem to be involved in intra molecular hydrogen bonds. In a second step, we have investigated the role played by Ca2+ ions on the possible conformational changes of fengycin. The addition of calcium gives rise to important modifications of the conformation. As fengycin has two glutamate residues, calcium is supposed to bind to their side chains. In conclusion, we have demonstrated that the conformation of fengycin is closely depending of the environment and the presence of calcium ions play an important role on the conformational changes of the lipopeptide. Moreover, spectra obtained both FTIR and CD methods ascertain the presence of turn conformation. [less ▲]

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See detailHow does elicitor and antimicrobial fengycin interact with plasma membranes of sensitive cells ?
Nasir, Mehmet Nail ULg; Eeman, Marc; Lins, Laurence ULg et al

Conference (2012, April)

Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ ... [more ▼]

Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ activity of surfactin. The cell target of its biological activities is supposed to be plasma membrane. In spite of these interesting biological activities, fengycin has not been extensively investigated probably because of the difficulties related to its production. In a first time; we have characterized the interfacial properties of fengycin by tensiometry measurements and demonstrated that this surface activity was pH-dependent. In a second time; we have investigated the interactions of the lipopeptide with membrane lipids using model membranes such as Langmuir monolayers and multilammelar vesicles (MLVs). Our results indicate that the lipopeptide was able to penetrate into different lipid monolayers showing a preference for sterol-containing monolayers. In order to better understand the mechanism of the interactions of fengycin with membranes at the molecular level, MLVs with or without fengycin have been analyzed by spectroscopic techniques. We have shown that conformational changes of the lipopeptide occurred in the presence of lipids and they were more significant in the presence of sterol. Moreover, tyrosine residues of the lipopeptide seem to play an important role in these interactions. In conclusion, we have determined that the surface-active behavior as well as the conformation of fengycin depends on its environment. We have also showed that the lipopeptide does not interact with all class of lipids in the same way and presents a preference for sterols. The presence of key groups within peptide cycle has also been supposed for the biological activities of the lipopeptide. [less ▲]

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See detailStructure, properties and obtention routes of flaxseed lignan secoisolariciresinol
Sainvitu, Pauline ULg; Nott, Katherine ULg; Richard, Gaetan ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(1), 115-124

Following a brief description of the structure and nomenclature of the lignan family, this review focuses on the flaxseed lignan secoisolariciresinol (SECO). The main properties, the analysis methods and ... [more ▼]

Following a brief description of the structure and nomenclature of the lignan family, this review focuses on the flaxseed lignan secoisolariciresinol (SECO). The main properties, the analysis methods and two routes for the preparation of SECO, i.e. extraction from renewable raw material and (hemi)-synthesis, are reviewed. Green methods recently developed for the first route and chemical syntheses inspired from biosyntheses for the second one are the main subjects of this paper. [less ▲]

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See detailNewly discovered natural functions for cyclic lipopeptides from rhizobacteria
Ongena, Marc ULg; Henry, G.; Deleu, Magali ULg et al

Conference (2012)

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See detailPurification of pectin from apple pomace juice by using sodium caseinate and characterisation of their binding by isothermal titration calorimetry
Happi Emaga, Thomas; Garna, Haikel; Paquot, Michel ULg et al

in Food Hydrocolloids (2012), 29

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See detailInteraction of Hexadecylbetainate Chloride with Biological Relevant Lipids
Nsimba Zakanda, Francis; Lins, Laurence ULg; Nott, Katherine ULg et al

in Langmuir (2012), 28(7), 3524-3533

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See detaild-Xylose-based bolaamphiphiles: Synthesis and influence of the spacer nature on their interfacial and membrane properties
Deleu, Magali ULg; Gatard, Sylvain; Payen, Emeline et al

in Comptes Rendus Chimie (2012), 15

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See detailPenetration behaviour of alkylbetainate chlorides into lipid monolayers
Nsimba Zakanda, Francis ULg; Nott, Katherine ULg; Paquot, Michel ULg et al

in Colloids and Surfaces B : Biointerfaces (2011), 86

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See detailAlkylbetainate chlorides: Synthesis and behavior of monolayers at the air-water interface
Nsimba Zakanda, Francis ULg; Laurent, Pascal ULg; Paquot, Michel ULg et al

in Thin Solid Films (2011), 520

In this study, cationic alkylbetainate chloride surfactants (CnBC, n = 10–16) are synthesized using more environment-friendly reagents (glycine betaine, thionyl chloride and primary alcohols) than in ... [more ▼]

In this study, cationic alkylbetainate chloride surfactants (CnBC, n = 10–16) are synthesized using more environment-friendly reagents (glycine betaine, thionyl chloride and primary alcohols) than in previous works (chloroacetyl chloride, trimethylamine and primary alcohols). The interfacial behavior of the CnBC monolayers is studied onto aqueous subphases at 20 °C using the Langmuir through technique. Different experimental conditions including pH, temperature, sodium salts and Na2SO4 ionic strength are investigated. The results obtained have shown that the CnBC with a hydrocarbon chain length ≥ 14 are able to form insoluble monolayers. The C16BC monolayer stability checked by the compression–expansion cycles has shown a superimposition of isotherms in the whole liquid-condensed region and an irreversible rearrangement of the molecules at high compression. The C16BC monolayer is not influenced by the pH and the presence of monovalent anions but it is influenced by the temperature, the divalent anions and the ionic strength. It has exhibited a great stability whatever the experimental conditions. [less ▲]

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See detailSynthesis and physico-chemical characterization of bolaamphiphiles derived from alkenyl D-xylosides
Deleu, Magali ULg; Damez, Céline; Gatard, Sylvain et al

in New Journal of Chemistry (2011), 35

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See detailATSPO-related protein localizes to the early secretory pathway in Arabidopsis, but is targeted to mitochondria when expressed in yeast
Vanhee, Celine; Guillon, Stéphanie; Masquelier, Danièle et al

in Journal of Experimental Botany (2011), 62(2), 497-508

Detailed reference viewed: 28 (7 ULg)