Dissertations / Theses on the topic 'Flavonoïden'
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De, Oliveira Eduardo Basilio. "Simulations moléculaires appliquées à l'acétylation de flavonoïdes catalysée par des lipases : influence des structures de la lipase e du flavonoïde sur la régiosélectivité de la bioconversion." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2009. http://tel.archives-ouvertes.fr/tel-00452422.
Full textDe, Oliveira Eduardo Basilio. "Simulations moléculaires appliquées à l'acétylation de flavonoïdes catalysée par des lipases : influence des structures de la lipase et du flavonoïde et sur la régiosélectivité de la bioconversion." Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL095N/document.
Full textFlavonoids are plant-produced polyhydroxylated compounds, well-known for their beneficial health effects. In order to obtain more stable and soluble derivatives for incorporation in hydrophobic formulations without damaging the biological activities of the native molecules, a solution consists to perform a regioselective acylation of these molecules. This can be accomplished by using lipase biocatalysts, in organic media. Several experimental studies dealing with such processes are available, but none of them give any explanation, at the molecular level, for the regioselectivity of such reactions. This study aimed to apply different molecular modelling tools in order to better understand, at the molecular level, the selectivity properties of the acetylation of three flavonoids (quercetin and its glycosylated derivatives isoquercitrin and rutin), by using the lipases CALB and PCL. Firstly, docking simulations were applied, in order to obtain the most probable positions and orientations of the flavonoids in the cavities of acetylated lipases. Then, molecular dynamics simulations were performed, aiming to study the structural stability of the complexes upon a period of time and specially the stability of the enzyme-substrates interactions. Finally, quantum chemical simulations (DFT) were applied to evaluate the chemical reactivity of the flavonoids as docked in the complexes. The trends observed during the simulations were well correlated with previous experimental results on the acetylation reaction of these flavonoids. Overall, the results showed that the selectivity in such reactions depends upon the substrates (flavonoid and acetate) orientations in the enzyme catalytic cavity, the intermolecular interactions that stabilize these substrates and the intrinsic chemical reactivity of the flavonoids OH groups reaching the catalytic residues
Anthoni, Julie. "Synthèse enzymatique, modélisation moléculaire et caractérisation d'oligomères de flavonoïdes." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL097N/document.
Full textThe aim of this work is the elaboration of rutin and esculin oligomerization process by the laccase from Trametes versicolor. A parallel synthesis process and on-line analysis of reaction media by SEC-UV and MALDI-TOF have been elaborated. The MALDI-TOF analysis has revealed the formation of simple bridges between rutin and esculin units, up to degree of oligomerization of 6 and 9 respectively. An ether bond has been observed by FTIR spectrometry for the rutin oligomers. Finally, the NMR analysis has revealed the formation of C-C and C-O bridges both on phenolic and the sugar parts of the flavonoids. At low pH and temperature, the elongation of the chain is favored, whereas increasing the dielectric constant of the solvent or the temperature favors the production of rutin oligomers. The limitation of oligomers mass is explained by the inhibition of the enzyme, probably due to the highest chelation properties of oligomers. In the case of oligorutin, a decrease of antiradical activity and an increase of xanthine oxidase inhibitory activity have been observed when the oligomers molecular mass increases. In the case of esculin oligomers, these two activities increase with the increase of the oligomers mass. For these two types of oligomers, the water solubility is considerably increased. For the oligorutins, this augmentation has been correlated to a dense network of H-bonds, which has been demonstrated by molecular modeling. Globally, the molecular modeling approach in vacuum and in solvent has allowed to establish structure-activity relationship
Fargeix, Guillaume. "Étude des mécanismes d'oxydation de flavonoïdes en relation avec leur activité antioxydante : effets anti- et pro-oxydants dans l'inhibition de la peroxydation lipidique par les flavonoïdes." Lyon 1, 2000. http://www.theses.fr/2000LYO10281.
Full textViljanen-Tarifa, Eeva Anneli. "Contribution à l'étude des mécanismes d'action cellulaires et moléculaires des flavonoïdes." Paris 12, 1992. http://www.theses.fr/1992PA120055.
Full textTruong, Công Tri. "Nanoformulations pour la protection de flavonoïdes instables : exemple de la quercétine." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA114850.
Full textThis thesis focuses on the development of polyoxylglycérides-based lipid nanoparticles to protect labile APIs, quercetin (a fragile antioxidant flavonoid) in this case. Different nanoparticulate systems were prepared by high pressure homogenization with particle size between 100 to 200 nm. These nanodispersions are very stable over several years at room temperature. Encapsulation of quercetin in compartmented lipid nanoparticles and preparation of nanocrystals have increased significantly its content in the dispersion and effectively improve its physical and chemical stability
Strauel, Philippe. "Nouvelle voie de synthèse des flavanols-3." Mulhouse, 1985. http://www.theses.fr/1985MULH0013.
Full textCrespy, Vanessa. "Etude de l'absorption intestinale et du métabolisme splanchnique des flavonoi͏̈des chez le rat." Clermont-Ferrand 1, 2001. http://www.theses.fr/2001CLF1PP09.
Full textCarrié, Hélène. "Développement de sondes moléculaires appliquées à l’étude de la biosynthèse des flavonoïdes." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR15012/document.
Full textFlavonoids are natural substances known for their anti-inflammatory, anti-cancerous and anti-virals properties in humans. In plants, they are one of the molecules responsible for fighting pathogens. The flavonoid biosynthesis pathway as been greatly studied in plants, especially in that of the grapevine: Vitis vinifera. However, detailed studies of the exact function of the enzymes involved in the last steps of the biosynthesis of anthocyanins and proanthocyanidins remains largely lacking.The study that we propose is to synthesize molecular probes designed to specifically interact with enzymes involved in the last stages of flavonoids biosynthesis. Our probes, based on the emerging chemical proteomic technology, activity- and affinity based protein profiling (ABPP), were validated with a model enzyme: leucoanthocyanidin dioxygenase (LDOX). After which, they were used with complex protein mixtures from Vitis vinifera
Pessel, Freddy. "Synthèse éco-compatible de flavonoïdes fonctionnalisés par le glucose comme antioxydants potentiels." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00986261.
Full textBen, Rhouma-Martin Ghada. "Oligomérisation enzymatique de flavonoïdes et évaluation des activités biologiques des oligomères synthétisés." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0017/document.
Full textRutin and esculin have been polymerized by laccase. Five fractions with between 2127.42 and 8331.85 g/mol for oligorutins, and between 688.12 and 6973 g/mol for oligoesculins, were obtained. Fourier transformed infrared analysis showed that oligorutins were formed through C-C, C-O and C=O linkages, while oligoesculins were obtained through C-C linkages. Oligorutins and oligoesculins show a higher solubility in water and a lower solubility in ethanol compared to their monomers. The oligomerization of rutin decrease its antiradical capacity, while oligoesculin fractions demonstrated a high antiradical activity compared to monomeric esculin. Oligomer fractions showed a better iron chelating power, xanthine oxidase inhibition, copper reducing power (CUPRAC), antigenotoxic activity, and splenocytes stimulator activity compared to their monomers. Oligorutin and oligoesculin exhibited an important anti-inflammatory capacity through the nitric oxide inhibition. Moreover, oligorutin fractions demonstrated an immunostimulatory effect proportional to their degree of oligomerization, while oligoesculin fractions showed an immunostimulatory effect inversely proportional to their degree of oligomerization
Arnaudinaud, Valérie. "Hémisynthèse et synthèse totale de flavonoi͏̈des marqués." Bordeaux 2, 2000. http://www.theses.fr/2000BOR28764.
Full textAuger, Bathide. "Analyses biochimique et moléculaire du métabolisme des flavonoïdes dans la graine de colza (Brassica napus L. ) : vers l’élucidation des déterminants impliqués dans la pigmentation des téguments." Rennes, Agrocampus Ouest, 2010. http://www.theses.fr/2010NSARC096.
Full textProcyanidins (PCs) are seed coat specific flavonoids that confer brown pigmentation to the B. Napus seed but impair the qualities from both seed and derived meal. Thus, the yellow-seeded trait (low-PC content) in Brassica is associated with increased seed oil content and with improved meal quality (protein content and meal digestibility). However, development of yellow-seeded lines requires better knowledge of the seed flavonoid pathway in B. Napus. Therefore, the present work aimed to identify and characterize the biochemical and molecular key determinants involved in the PC biosynthetic pathway in B. Napus seeds. In a first step, the profiling of seed coat flavonoids was monitored during seed development in eight black-seeded B. Napus genotypes. Sixteen different flavonoids including (–)-epicatechin, PCs and flavonols were identified and quantified by LC-ESI-MS. High amounts of PCs accumulated into the inner integument, especially within the endothelium and in the micropylechalaza region. In parallel, a “candidate gene” approach was undertaken to clone the Brassica orthologs from seven TRANSPARENT TESTA (TT) genes involved in seed flavonoid metabolism in A. Thaliana. Our results reported that oilseed rape TT genes (Bna. TT) belonged to small multigene families of 2 to 6 copies. The different paralogs were expressed in developing seeds following a spatio-temporal profile that was consistent with the PC accumulation pattern. In addition, phenotypic complementation was observed when Bna. TT genes were introduced into the corresponding Arabidopsis tt mutants. Finally, Bna. TT genes mapped to oilseed rape genomic regions that displayed collinearity with Arabidopsis counterparts and some of them displayed putative co-localisations with QTLs for seed pigmentation. In a last part, results from both metabolic and molecular analyses allowed identification of specific low-PC oilseed rape genotypes among lines with altered seed pigmentation. Future prospects will include the identification of mutations within Bna. TT genes through reverse genetic approach (TILLING) in order to establish a wider genetic diversity panel for low-PC trait. It will be also necessary to evaluate the impact of low-PC mutations on seed quality as well as on plant physiology
Chaboud, Annie. "Contribution à l'étude botanique et biochimique de Thea chinensis Sims var. Macrophylla Sieb : thé Yunnan Tuocha - Ternstroemiacées." Lyon 1, 1985. http://www.theses.fr/1985LYO1W233.
Full textDumon, Marie-Claude. "Recherches analytiques sur les pycnogénols." Bordeaux 2, 1990. http://www.theses.fr/1990BOR2E001.
Full textWallet, Jean-Claude. "Synthèse et analyse conformationnelle (RNM, RX, mécanique moléculaire) de flavones polyméthoxylées : relation avec leur activité antimutagène." Aix-Marseille 3, 1991. http://www.theses.fr/1991AIX30047.
Full textRahaoui, Hassan. "Application du couplage catalytique par voie boronique dans la synthèse d'arylflavonoïdes et de biflavonoïdes." Mulhouse, 1991. http://www.theses.fr/1991MULH0177.
Full textFalcimaigne-Cordin, Aude. "Etude d'un procédé de prodction enzymatique des esters de flavonoïdes : cinétique, purification, étude conformationnelle et caractérisation des propriétés physico-chimiques et biologiques." Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPLA002.
Full textThis work aims to develop an enzymatic process for the synthesis of flavonoids esters : kinetic study, purification and determination of the physico-chemical and biological properties. Various solvents were tested. Tert – amyl alcohol was selected as solvent and the immobilized lipase B of Candida Antarctica as biocatalyst. The results obtained show that the performances of the reaction are influenced by the water content of the medium, the nature of the flavonoid (rutin, esculin, naringin) and of the acyl donor, the substrates and biocatalyst concentrations, the temperature of the reaction. Under the optimal conditions, the conversion yields are about 80 % and the productivity of 2,5g/L/h. The reaction is selective, but under certain conditions it is possible to obtain the mono and diesters of flavonoid. In this study, ten acyl donors and four flavonoids were studied. The purification of a broad range of esters was successively carried out by liquid-liquid extraction. The purity of the obtained products is higher than 90 %, but the esters losses are variable according to the acyl donor. The solubility, the stability, the photoprotective an d antioxidant activities and the interactions flavonoid-membrane of the different flavonoids esters were also studied and compared to native flavonoids. These properties generally either were improved, or preserved. So, the rutin acylation bu C>16 acids improves the solubility of rutin in lipophilic solvents, while preserving its antioxidant activity. The ability of rutin to interact with lipids bilayers was also modulated by the presence of the aliphatic chain. The antioxidant activity and the photostability were connected to several descriptors resulting from the molecular modelling
Bakhtiar, Amri. "C-glycosylflavones de Galipea trifoliata Aublet et Raputia paraensis Ducke (Rutaceae)." Montpellier 1, 1990. http://www.theses.fr/1990MON13513.
Full textDaigneault, Kathleen. "Contribution à l'étude de l'influence des flavonoïdes sur la voie catabolique du biphényle." Mémoire, Université de Sherbrooke, 2003. http://savoirs.usherbrooke.ca/handle/11143/4567.
Full textSemmar, Nabil. "Analyse de la diversité chimique (flavonoïdes et saponines) de l'espèce Astragalus caprinus (fabaceae)." Lyon 1, 2000. http://www.theses.fr/2000LYO10244.
Full textBois, Frédéric. "Analogues de flavonoïdes inhibiteurs de la glycoprotéine P, modulateurs potentiels de la chimiorésistance." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE18001.
Full textDiharce, Julien. "Étude par modélisation moléculaire de systèmes multienzymatiques impliqués dans la biosynthèse des flavonoïdes." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4095/document.
Full textFlavonoids, some natural compounds exhibiting antioxidant properties, are synthesized along enzymatic cascades involving several enzymes. It has been recently proposed that some of these enzymes are involved in the formation of large transient macromolecular edifices, called metabolon, interacting with cellular membrane. Such molecular complexes should allow direct metabolites transfer from one active site to the other (substrate channeling phenomenon), minimizing diffusion time and solvation effects. The present work aims to establish a first model of a metabolon involving 3 enzymes of the flavonoid biosynthesis: the dihydroflavonol 4-reductase (DFR), the flavonoid 3'-hydroxylase (F3'H) and the leucoanthocyanidin reductase (LAR). The study of such large molecular system requires a multiscale approach based on i) hybrid QM/MM methods to decipher enzymatic mechanism, ii) molecular dynamic simulations in microsecond timescale to estimate thermodynamic and kinetic properties and iii) protein-protein docking at coarse-grained resolution. These different levels of theory allow us to establish a first model of a three-enzymes-metabolon in interaction with a model of cellular membrane
Alluis, Bertrand. "Modifications chimiques de flavonoïdes : études de leurs pouvoirs complexant (protéines, métaux, pigments) et antioxydant." Lyon 1, 2000. http://www.theses.fr/2000LYO10203.
Full textLeal, Filipe Paulo. "Sur les mécanismes moléculaires de l'action des flavonoïdes lors d'un stress oxydant ou photooxydant." Paris 7, 2005. http://www.theses.fr/2005PA077204.
Full textThe skin, a highly vascularized organ, is the interface with the environment and a potential target of oxidative injury induced by chemical and biological agents or of the photo-oxidative stress caused by UVA radiation. We examined the molecular mechanisms involving flavonoids in the protection of skin constituents against oxidative and photo-oxidative stresses. In plasma, the addition of Cu2"1" induces the consumption of urate, a major endogenous antioxidant, and the initiation of Hpid peroxidation. The flavonoids myricetin, quercetin, and kaempferol inhibit lipid peroxidation and urate consumption. Although at some concentrations the addition of exogenous urate has a prooxidant effect by accelerating lipid peroxidation, we observed that exogenous urate displays synergistic antioxidant properties with quercetin, luteolin, rutin and catechin. The antioxidant potential of quercetin is strongly reduced upon binding to albumin. As a result we have synthesized 2-styrylchromones possessing antioxidant potential superior to quercetin. The pro- and anti-oxidant effects of flavonoids were also demonstrated in LDL solutions. Puise radiolysis measurements showed that quercetin incorporated into LDL efficiently repairs oxidized Trp and Tyr residus of native LDL Apo-B 100. This repair contributes along with thé inhibition of lipid peroxidation to the antioxidant effect of quercetin against LDL oxidation. Regarding the protection against the photo-oxidative stress in human skin fibroblasts cultures, the flavonol quercetin, the flavones luteolin and rutin, and catechin inhibit lipid peroxidation and cell death induced by UVA alone or photosensitised by cyamemazine, a phototoxic neuroleptic. On the other hand, an amplification of the photodamage may be observed with isoflavones, suggesting the difficulty to apply general rules when establishing a protective antioxidant strategy against phototoxic agents
Zhao, Chenyang. "Effets antioxydants et protection de l'ADN par des phénylpropanoïde glycosides (PPGs) et des flavonoïdes." Paris 7, 2004. http://www.theses.fr/2004PA077184.
Full textBoukharta, Mohamed. "Étude des flavanoïdes [i. E. Flavonoïdes] de Vitis vinifera : structure des proanthocyanidines des pépins de raisin, de sarments et de feuilles de vigne." Vandoeuvre-les-Nancy, INPL, 1988. http://www.theses.fr/1988NAN10022.
Full textSappe, Françoise. "Etude de génines stéréoi͏̈diques et de flavonoi͏̈des issu de Glycyrrhiza S." Aix-Marseille 3, 1995. http://www.theses.fr/1996AIX30026.
Full textBerrin, Jean-Guy. "Etude des relations structure-fonction de la beta-glucosidase cytosolique humaine." Aix-Marseille 3, 2002. http://www.theses.fr/2002AIX30089.
Full textThe full-length cDNA encoding the human cytosolic b-glucosidase (CBG) was expressed in the yeast Pichia pastoris. CBG demonstrated a broad specificity with respect to the glycone moiety of aryl-glycosides and significant activity towards flavonoid glucosides, suggesting that human CBG may play a critical role in the first step of their metabolism. Site-directed mutagenesis was used to identify the key residues involved in aglycone recognition and substrate specificity of the human CBG. All CBG mutants, of amino acids located in the substrate-binding pocket, showed a decreased in activity towards a broad range of substrates as compared to the wild-type CBG. Kinetic analyses indicated that Val168 and Phe225 play an important role in the substrate specificity of human CBG
Le, Roux Erwan. "Etude des composés phénoliques et des systèmes enzymatiques impliqués dans le brunissement du péricarpede litchi (litchi chinensis sonn. )." Aix-Marseille 3, 1999. http://www.theses.fr/1999AIX30010.
Full textCotin, Sébastien. "Cytomégalovirus humain, mutations de résistances, et nouveaux antiviraux." Limoges, 2011. https://aurore.unilim.fr/theses/nxfile/default/f3d249e6-e73f-444a-a399-704ab7479c43/blobholder:0/2011LIMO310B.pdf.
Full textHCMV is a ubiquitous herpesvirus which infects about fifty percent of the population and persists at latent state after primo infection. Severity of HCMV infections during AIDS, after organ or hematopoietic stem cells transplant and during pathologies that require or lead to cell immunosuppression justify the use of antiviral, curative and preventative treatments. The few antiviral drugs currently available in clinical practice reveal a toxicity that limits their use and lead to an emergence of conferring mutations that offers resistance to these molecules. The key players of this resistance are UL54 and UL97 genes that encode respectively viral DNA polymerase and a kinase necessary to the activation of the most used therapeutic molecule which is the ganciclovir. During our work, we have studied the emergence of resistance mutations within multicenter cohort of transplant recipients and we could have highlighted new resistance mutations. We have also developed a technique based on the BAC technology which allowed us to characterize the impact of two new mutations in UL54. Within the similar objectives, we developed in vitro nonradioactive kinase activity test in order to determine the mutations impact on UL97 activity and a structural study lead us to the hypothesis that UL27 might be a potential cofactor of this kinase and might have a role in the resistance. Finally, we have highlighted at least three flavonoids, molecules from plant world, inhibiting actively in vitro HCMV replication
Ghidouche, Souhila. "Produits d’oxydation de flavonols et de flavanols par la laccase de Trametes versicolors." Rennes, Agrocampus Ouest, 2008. http://www.theses.fr/2008NSARB187.
Full textFlavonols and flavan-3-ols are two important sub-classes of flavonoïds, they are characterized by their biological properties which are important for both humans and plants. However, these properties are affected by the oxidation phenomenon. Laccases are among the enzymes involved in these enzymatic reactions. A few studies have been dedicated to the oxidation mechanisms and to the structures of the reaction products. The present study aims to identify and elucidate the structure of the oxidation products of flavanols and flavan-3-ols by the laccase of Trametes versicolor and compare their formation mechanisms. The first part is a review which clearly shows the strong structure-antioxidant activity relationship of flavonoïds. In the second part, we present the oxidation products generated by Arabidopsis thaliana laccase and Trametes versicolor laccase. The study of the structure of the oxidation products according to the substrate structure allowed the identification of the oxidation mechanisms. It also allowed to put forward that the structure specificities of the substrate affect the reaction’s outcome
Chalumeau, Céline. "Développement d’outils chimiques pour l’élucidation de la biosynthèse des flavonoïdes du raisin : anthocyanes versus proanthocyanidines." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14188/document.
Full textRemarkable progress toward the complete elucidation of the biosynthesis of flavonoids has been accomplished during the last decade, but the final step leading to proanthocyanidins still remain to be elucidated, in particular, the exact nature of starter and extension units as well as the enzymatic or non enzymatic condensation process. In order to answer whether some specific enzymes are involved in the biosynthesis of grapevine proanthocyanidins, we have developped a chemical proteomics approach, with an affinity chromatography-based tool in which a flavanol type substrate is loaded on an appropriate solid support. The validation of these tools with the LDOX enzyme from Vitis vinifera was developped and performed in this Ph.D work
Gatouillat, Gregory. "Stratégies de sensibilisation de cellules tumorales résistantes à la chimiothérapie : induction d'anticorps, utilisation de flavonoïdes." Reims, 2008. http://theses.univ-reims.fr/sante/2008REIMP203.pdf.
Full textIsorez, Géraldine. "Contribution à la chimie des flavonoïdes : Accès à des analogues de pigments du vins rouges." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/ISOREZ_Geraldine_2007.pdf.
Full textMarion, Chantal. "Contribution à l'étude botanique, chimique et taxinomique du genre Forsythia Vahl. (Oleaceae)." Montpellier 1, 1990. http://www.theses.fr/1990MON13506.
Full textKothan, Suchart. "Induction de l'apoptose et de la réversion de la résistance multiple aux drogues engendrées par les flavonoïdes et mise en évidence de la cible intracellulaire de ces molécules dans les cellules cancéreuse." Paris 13, 2004. http://www.theses.fr/2004PA132010.
Full textPouget, Christelle. "Pharmacomodulation de flavonoi͏̈des : conception et synthese de nouveaux inhibiteurs de l'aromatase." Limoges, 2001. http://www.theses.fr/2001LIMO308H.
Full textChosson, Elizabeth. "Contribution à l'étude phytochimique de Rhododendron ferrugineum L. , Ericaceae." Lyon 1, 1996. http://www.theses.fr/1996LYO1T132.
Full textPujol, Jean Gabriel. "Nouvelles synthèses stéréosélectives des flavanols-3 cis et trans." Mulhouse, 1990. http://www.theses.fr/1990MULH0142.
Full textBidzinski, Przemyslaw. "Oxydation des flavonoïdes dans les graines d'Arabidopsis thaliana : Analyse fonctionnelle du gène TRANSPARENT TESTA 10 codant une polyphénoloxydase de type laccase." Paris 11, 2009. https://tel.archives-ouvertes.fr/tel-02177497.
Full textThe purpose of this thesis was to perform a functional characterization of the TRANSPARENT TESTA 10 (TT10) gene encoding a laccase (AtLAC15) involved in flavonoid oxidation in Arabidopsis seed. A part of the work was devoted to the analysis of the regulatory mechanisms controlling the developmental pattern of TT10 gene expression in seeds and vegetative plant parts. The functional 5’-dissection of a 2. 0-kb promoter realized with the uidA reporter gene encoding b-glucuronidase (GUS) was performed to identify regions responsibles for activation in seed and other plant organs. TT10 promoter happens to be activated exclusively in seed coat and siliques. Directed mutagenesis was undertaken to precise the regulatory role of in silico-detected cis-acting regulatory elements located in a 194-bp region necessary for expression in seed coat. TT10 gene expression assessed in different tissues at various stages of development using qRT-PCR matched promoter activity pattern. Natural variation for TT10 expression among Arabidopsis accessions was also detected, with the levels of TT10 mRNA in Cvi, Ler and Sha being strongly reduced compared to the ones in Ws, Col and Bay. The impact of this molecular polymorphism on seed flavonoid composition, as analyzed on mature seeds with LC-MS, is discussed. TT10 appeared to be the only member of the laccase gene family to be strongly expressed in seeds
Cren-Olivé, Cécile. "Synthèse, physico-chimie et analyse de flavan-3-ols." Lille 1, 2001. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2001/50376-2001-67.pdf.
Full textDeluc, Laurent. "Identification et caractérisation fonctionnelle de deux gènes régulateurs du métabolisme des composés phénoliques de la baie de raisin." Bordeaux 1, 2004. http://www.theses.fr/2004BOR12839.
Full textMonserrat, Jean-Philippe. "Synthèse, caractérisation et criblage biologique de nouveaux dérivés ferrocéniques des flavonoïdes : chalcones, aurones, flavones et flavonols." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://pastel.archives-ouvertes.fr/pastel-00661343.
Full textMonserrat, Jean-Philippe. "Synthèse, caractérisation et criblage biologique de nouveaux dérivés ferrocéniques des flavonoïdes : chalcones, aurones, flavones et flavanols." Paris 6, 2011. http://www.theses.fr/2011PA066666.
Full textRenier, Adeline. "Approche pluridisciplinaire de la Symbiose Methylobacterium nodulans / Crotalaria podocarpa." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2008. http://tel.archives-ouvertes.fr/tel-00343650.
Full textCuoco, Guillaume. "Etude chimique et caractérisation de principes colorants historiquement employés dans l’impression des indiennes en Provence." Electronic Thesis or Diss., Avignon, 2009. http://www.theses.fr/2009AVIG0232.
Full textThis work concerns the study of three tinctorial plants: madder, buckthorn and weld. These plant species produced many cultures in Provence and represented the principal raw material in red and yellow dyes for dyers and artists. An optimisation of extraction conditions for madder dyes, using ultrasounds, was carried out with a statistical model. This easy, fast and effective extraction process was compared with two other conventional techniques. A cytohistological study on madder roots permits to examine effects produced by the different extraction processes. Cells reveal, after ultrasonic extraction, profound structural alterations, explaining the high yield in extracted dyes in comparison with classical methods. A fundamental study on the dyes identification extracted from Rhamnus species green fruits was carried out. A chromatographic approach using HPLC-UV-MS permits to identify the flavonol fraction. It is mainly composed of glycosiled compounds where the rhamninosid part is linked in position 3 or 4’ on the flavonol nucleus. 3-O-acetyl-rhamninosid derivatives were also characterised and they are specific to Rh. saxatilis species. Ripe fruits contained anthraquinonic compounds that were separated from flavonols and concentrated using Solid Phase Extraction (SPE). After NMR analyse, acetyl rhamnosid and arabinosid derivatives of émodine, never described in the specialised literature, were identified as emodin-6-O-(3',4'-diacetyl)-arabinopyranosid and emodin-6-O-(2',3',4' triacetyl)-arabinopyranosid were only present in Rh. alaternus. Yellow dyes of weld (Reseda luteola) were analysed by capillary electrophoresis. In comparison with HPLC, a reduced run time was observed while preserving a suitable separation. These experimental results were successfully applied to the study of ancient samples belonging from museums and including “indiennes” of the XIXth century. Finally, dying tests were carried out, in collaboration with Les Olivades society, in the aim to develop textiles containing natural dyes
Aberkane, Leïla. "Etude des mécanismes de structuration d’assemblages β-lactoglobuline-gomme d’Acacia en présence d’un flavonoïde, la quercétine." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL045N/document.
Full textFlavonoids are promising ingredients in food and non food applications through their antioxidative and biological properties. However, their negligible solubility in most solvent renders problematic technological developments. In order to overcome this drawback, the approach followed in this study was the incorporation of flavonoids in stable and functional particles based on biopolymers (protein-polysaccharide). The main objective of this thesis was to acquire knowledge at different scales to study the mechanisms of interaction and linkage between a flavonoid, quercetin, and two biopolymers, B-lactoglobulin (BLG) and Acacia gum (AG). In a first step, we were able to develop submicronic particles (Dh : ~250 nm) of quercetin-Acacia gum (GAQ) based on a core of quercetin and a shell of Acacia gum, reflecting a behavior of soft particles. In a second step, we investigated the assembly mechanisms GAQ with BLG at pH 4.2 and 25 ° C. The thermodynamic parameters of interaction were determined by isothermal titration calorimetry (ITC) and show binding isotherm characterized by an exothermic-endothermic sequence. The various structural entities formed during the complexation between GA and BLG or BLG and GAQ were characterized using the same approach as for the ITC titration. Finally, measurements using infra-red Fourier transform (FTIR) showed changes in the secondary structure of BLG after interaction with the GA and the GAQ. There was a significant loss of secondary structures (α-helices and β-sheets), even more pronounced in presence of quercetin
Hichri, Imène. "Identification et caractérisation fonctionnelle de gènes régulateurs de la voie de biosynthèse des flavonoïdes chez la Vigne." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13875/document.
Full textPhenolic compounds, and more specifically flavonoids (flavonols, condensed tannins and anthocyanins), are key components of the grapevine and wine quality. Because of their antioxidant activities, these compounds are of interest in pharmacological and cosmetic industries, as well as being beneficial to the human diet. Previous work on model plants showed that the flavonoid pathway was mainly regulated by the MYB and bHLH transcription factors, and WD40 proteins. In the grapevine (Vitis vinifera L.), only MYB regulators have been identified until now, and no bHLH or WD40 have been characterised. In this work, several approaches were used to identify new transcription factors involved in grapevine flavonoid biosynthesis. Firstly, the VvMYB5b protein was used as a bait in a large scale two hybrid experiment in yeast (Saccharomyces cerevisiae). Secondly, the promoter of the VvDFR gene, coding a central enzyme of the flavonoid pathway, was chosen to conduct a large scale one hybrid experiment, also in yeast. Finally, a “gene candidate” approach allowed identification of the bHLH transcription factors VvMYC1 and VvMYCA1. VvMYCA1 expression profile in berry skin and seeds correlates with condensed tannins synthesis, whereas VvMYC1 transcript accumulation in these tissues and the grapevine inflorescence correlates with condensed tannins, anthocyanins and flavonols accumulation. In yeast, VvMYC1 could physically interact with different MYB partners regulating the anthocyanin or the condensed tannins biosynthesis. This interaction was confirmed by transient promoter assays in grape cell suspensions, where co-expression of VvMYC1 with specific MYB partners activated the UFGT and ANR promoters. Likewise, this interaction induced anthocyanin accumulation in grape cells, as well as in tobacco leaves and Arabidopsis. Eventually, additional transient promoter assays revealed that VvMYC1 is involved, with VvMYBPA1, in feedback regulation of its own expression
Marfak, Abdelghafour. "Radiolyse gamma des flavonoïdes : étude de leur réactivité avec les radicaux issus des alcools : formation de depsides." Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/8005fabb-db8a-4d8d-ac3c-cbb52dab3edf/blobholder:0/2003LIMO330E.pdf.
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