References of "Deleu, Magali"
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See detailLIPID INTERACTION PROPERTIES OF NOVEL RHAMNOLIPIDS
Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg; Lins, Laurence ULg et al

Conference (2013, November)

Biosurfactants which are surface active molecules produced by micro-organisms present a wide structural diversity (glycolipids, lipoaminoacids, lipopeptides, polymers,...) and numerous advantages compared ... [more ▼]

Biosurfactants which are surface active molecules produced by micro-organisms present a wide structural diversity (glycolipids, lipoaminoacids, lipopeptides, polymers,...) and numerous advantages compared to their chemically synthesized counterparts. Among glycolipids, rhamnolipids which are secondary metabolites produced mainly by strains of Pseudomonas aeruginosa, have drawn particular attention as they have several interesting biological properties such as antimicrobial, antiphytoviral, zoosporicidal and plant defense elicitor activities [1-3]. It is generally recognized that these activities must be linked to the interaction of these molecules with constituents of biological membranes [4] but the detailed mechanism is far from being fully understood. In our laboratory, new rhamnolipids with various chain lengths and with or without a terminal carboxylic acid function were obtained via the development of a synthesis procedure consisting of two biocatalyzed steps involving naringinase and lipase [5]. The objective of this work was to investigate their interaction with model membranes in relation with their structure in order to give insight about the mechanism of their biological action. A range of complementary experimental and modelling methods was used to analyze their interaction with membrane models. Results reveal differential interaction with lipids according to the structure of the rhamnolipid. The nature of the lipid is also a key parameter for the ınteractions. [less ▲]

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See detailINFLUENCE OF THE NATURE OF SUGAR RESIDUES ON THE INTERACTIONS OF SYMETRIC SUGAR- BASED BOLAFORMS WITH MODEL MEMBRANES
Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg; Lins, Laurence ULg et al

Poster (2013, November)

Glycolipid surfactants constitute a class of natural compound having interest in biological field such as antifungal, antiviral and plant-elicitor and for pharmaceutical formulation as well as for food ... [more ▼]

Glycolipid surfactants constitute a class of natural compound having interest in biological field such as antifungal, antiviral and plant-elicitor and for pharmaceutical formulation as well as for food and cosmetic field. Their action may be modulated through their interactions with plasma membranes of target cells and more particularly by their interactions with membrane lipid molecules. Among glycolipid surfactants, bolaforms constitute an important class; they are composed of two hydrophilic heads connected by a hydrophobic carbon segment.Their interest lies mainly in the development of the efficient and low cost lipid-based drug delivery systems. In this context, our work was focused on two sugar-based bolaforms. They are composed by two identical hydrophilic head constituted by xylose ( BolaX) or rhamnose ( BolaR), connected by an ether link to a hydrocarbon segment with an insaturation. The interactions of  BolaX and BolaR with model phopsholipid and phospholipid/sterol model membranes (Langmuir monolayers at the air-water interface and multilamellar vesicles) were investigated with biophysical and in silico approaches. Our results indicate that both bolaforms interact with model membranes at the level of hydrocarbon chain and, at the phosphate and the carbonyl group of phospholipids. The presence of sterol in the system has an influence on insertion of bolaforms and change slightly the nature of the interactions. The insertion of BolaR within a phospholipid bilayer was deeper than that of  BolaX and its interactions with phospholipids were energetically more favorable, suggesting an important role of the nature of sugar residue. [less ▲]

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See detailEliciteurs dérivés de rhamnolipides : synthèses, modélisations et activités biologiques
Mayon, Patrick; Ait Barka, Essaid; Baillieul, Fabienne et al

Poster (2013, July 04)

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See detailDevelopment of formulated elicitors to control bioagressors of wheat
Le Mire, Géraldine ULg; Deleu, Magali ULg; Ongena, Marc ULg et al

Scientific conference (2013, July)

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See detailAnalysis of the interactions of xylose-based bolaforms with model membranes
Nasir, Mehmet Nail ULg; Monhonval, Pierre; Legrand, Vincent et al

Poster (2013, June)

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in ... [more ▼]

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in pharmaceutical and cosmetic fields and of their original physicochemical properties. Xylose-based bolaforms have interfacial and membrane-interacting properties making them potential molecules for drug delivery systems. For this work, we chemically synthetized by metathesis in the presence of Grubbs I catalyzer, a novel symmetric bolaform composed of two xylose polar heads connected by an ether link to a hydrocarbon chain having 18 carbon atoms with an unsaturation (BolaX). We were able to obtain two bolaforms differing only at the level of the anomeric configuration of the xylose moieties, or orBolaX). The surface activities of both compounds were analyzed. The anomeric configuration  gives interfacial properties at the air-water interface contrary to the  one. The interactions of the BolaX with model membranes were then analyzed in order to determine if it can be used for drug delivery systems. Our results show that BolaX were able to interact and insert within lipid monolayers containing phospholipids and sterols. In order to have informations at the molecular level of these interactions, another model membrane, called multilamellar vesicles (MLVs), containing phospholipids and sterols with or without  BolaX were prepared. Both MLVs were analyzed by the means of the FTIR spectroscopy. In parallel, we have calculated the interaction energy of the  BolaX with different lipid molecules by the means of the Hypermatrix method developed at our laboratory. Moreover, the insertion of the  BolaX within the lipid bilayers was simulated using our IMPALA method. Taking together, our findings indicate that BolaX would be a potential candidate for drug delivery systems because of its surface active properties and its ability to insert within membranes. [less ▲]

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See detailNovel phenolic glycolipids: antioxidant activity and effect on membrane models
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Draguet, Florian et al

Poster (2013, May 30)

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B ... [more ▼]

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as regards to their aromatic group.Theireffect on cell viability when an oxidative stress is induced was tested. In parallel, their interaction with cell models (liposomes) was studied through membrane fusion and permeability experiments. [less ▲]

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See detailValorisation de la biomasse en produits tensioactifs
Deleu, Magali ULg

Scientific conference (2013, May 30)

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See detailBiophysical characterization of the interaction of novel aromatic glycolipid surfactants with membrane models.
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Draguet, Florian et al

Poster (2013, May 15)

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic ... [more ▼]

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as a function of their aromatic group. Their interaction with membranes was studied with monolayer models and was predicted by a computational approach. The relationships between these data and their cytotoxicity and antioxidant properties evaluated on cell cultures are discussed. [less ▲]

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See detailBiophysical characterization of the interaction of novel aromatic glycolipid surfactants with membrane models.
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Nott, Katherine ULg et al

in World Academy of Science, Engineering and Technology (2013, May), 77

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic ... [more ▼]

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as a function of their aromatic group. Their interaction with membranes was studied with monolayer models and was predicted by a computational approach. The relationships between these data and their cytotoxicity and antioxidant properties evaluated on cell cultures are discussed. [less ▲]

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See detailBiophysical characterization of the interaction of novel aromatic glycolipid surfactants with membrane models.
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Nott, Katherine ULg et al

in World Academy of Science, Engineering and Technology (2013, May), 77

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic ... [more ▼]

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as a function of their aromatic group. Their interaction with membranes was studied with monolayer models and was predicted by a computational approach. The relationships between these data and their cytotoxicity and antioxidant properties evaluated on cell cultures are discussed. [less ▲]

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Peer Reviewed
See detailModeling simple lipid phase separation and effects of amphiphilic molecules on lipid domains
Lins, Laurence ULg; Deleu, Magali ULg; Mingeot-Leclercq, Marie-Paule et al

Poster (2013, April 28)

Detailed reference viewed: 16 (3 ULg)
See detailInteractions de glycolipides avec des membranes biomimétiques
Deleu, Magali ULg

Scientific conference (2013, March 18)

Les surfactants à base de sucre sont des composés d’intérêt pour les domaines alimentaire, cosmétique et pharmaceutique de par leur origine naturelle, leur biodégradabilité élevée et leur biocompatibilité ... [more ▼]

Les surfactants à base de sucre sont des composés d’intérêt pour les domaines alimentaire, cosmétique et pharmaceutique de par leur origine naturelle, leur biodégradabilité élevée et leur biocompatibilité. Récemment, certains ont également montré un potentiel dans le domaine de la protection des plantes. Depuis quelques années, les surfactants de type bolaforme ont reçu une attention particulière surtout pour leur potentiel d’exploitation en tant qu’agent d’encapsulation ou de vectorisation de médicaments. Leur structure est composée de deux têtes polaires connectées par un bras espaceur hydrophobe. Parmi les bolaamphiphiles, ceux à base de sucre offrent l’avantage de fournir une hydrosolubilité importante et une cytotoxicité réduite. Une connaissance approfondie des propriétés tensioactives et membranaires de ces nouveaux tensioactifs est une clef importante dans la compréhension de leurs mécanismes, d’une part, et d’autre part, dans l’optique d’une démarche prédictive dans la conception d’agents tensioactifs ciblant une application précise, du domaine physico-chimique ou biologique. Les outils tels que la technique de la cuve de Langmuir, la calorimétrie de titration isotherme, la spectroscopie de fluorescence et la spectroscopie infra-rouge ont été exploités afin de mettre en évidence l’influence de la longueur du bras hydrophobe, de la présence d’insaturation, de la stéréochimie des carbones anomères et de la nature des sucres sur les propriétés interfaciales et d’interaction/déstabilisation des membranes biologiques des bolaformes de sucre. [less ▲]

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See detailReusability study of Novozym® 435 for the enzymatic synthesis of mannosyl myristate in pure ionic liquids
Galonde, Nadine ULg; Richard, Gaetan ULg; Deleu, Magali ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013)

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See detailInteraction of fengycin with stratum corneum mimicking model membranes: a calorimetry study
Nasir, Mehmet Nail ULg; Eeman, Marc; Olofsson, Gerd et al

in European Biophysics Journal [=EBJ] (2013), 42(S1), 168

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See detailPhysico-chemical and membrane-interacting properties of D-xylose-based bolaforms. Influence of the anomeric configuration
Nasir, Mehmet Nail ULg; Legrand, Vincent; Gatard, Sylvain et al

in MATEC Web of Conferences (2013), 4

Sugar-based biosurfactants such as xylose-derived bolaforms have interesting properties, for example high biocompatibility and biodegradability which make them potential useful molecules in the ... [more ▼]

Sugar-based biosurfactants such as xylose-derived bolaforms have interesting properties, for example high biocompatibility and biodegradability which make them potential useful molecules in the pharmaceutical and cosmetic fields. Until now, no detailed analyses of the physico-chemical properties of these compounds have been undertaken. Two symmetrical D-xylose-based bolaforms were chemically synthesized where the two xylose heads are linked via an acetal link to a hydrocarbon chain containing 18 carbon atoms and an unsaturation. The two bolaforms differ only by their anomeric configuration: or The bolaform exhibits interfacial properties at the air-water interface which is not the case for the . FTIR spectroscopy showed that the interactions between the bolaform and POPC, a model phospholipid, involve the carbonyl groups of the phospholipid [less ▲]

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See detailInteractions of iturinic antibiotics with plasma membrane. Contribution of biomimetic membranes.
Nasir, Mehmet Nail ULg; Besson, Françoise; Deleu, Magali ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(3), 505-516

Iturinic antibiotics are produced by Bacillus subtilis strains and constitute a family including iturin A, mycosubtilin and bacillomycins D, F and Lc. They are cyclic lipopeptides having -amino fatty ... [more ▼]

Iturinic antibiotics are produced by Bacillus subtilis strains and constitute a family including iturin A, mycosubtilin and bacillomycins D, F and Lc. They are cyclic lipopeptides having -amino fatty acids linked up to a peptide constituted by seven -aminoacids with an invariable LDDLLDL chiral sequence. The first three -aminoacids containing the tyrosyl residue are the same for all members. They are well-known by their strong antifungal activities but they have also antibacterial and hemolytic properties. These biological properties are due to their amphiphilic nature allowing interactions with different membrane components. Sterols found in plasma membranes are the privileged interaction partners of these lipopeptides. Moreover, the tyrosyl residue of the iturinic antibiotics seems to play an important role during their fixation to the plasma membrane, the result of which is often the cellular lysis. Within plasma membranes, there are particular regions with high sterol content. These microdomains have a different composition compared to the rest of the membrane; they are enriched in certain lipids and proteins and they are involved in many key cellular processes. Their perturbation could then have an important impact on the cell. Due to their composition, these microdomains could constitute the preferential target of iturin antibiotics. This review aims to synthetize the works related to the biological activities of iturinic antibiotics and focusses especially to their understanding at the molecular level with a discussion on the key chemical groups of the iturin antibiotics and on the potentiality of microdomains to constitute a target for these molecules [less ▲]

Detailed reference viewed: 43 (12 ULg)