Thèses sur le sujet « Produits naturels – Dérivés »
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Bouraiou, Abdelmalek. « Synthèse d'hétérocycles quinoléiques à visée thérapeutique et d'analogues structuraux de produits naturels ». Rennes 1, 2009. http://www.theses.fr/2009REN1S126.
Texte intégralThis manuscript describes the preparation of new quinolines derivatives associated to heterocycles eg. Aziridine, pyrrolidine or pyrrole and some structural analogues of flavanones, flavonols and tetrahydroquinolones. In this context, we have developed two methods. The first one consists on the generation of the N-metalated azométhine ylide from a -iminoesters in presence of LiBr in basic medium. The second one is based on the thermolysis of the N-alkylaziridine, which react with DMAD to offer N-alkylpyrroles and Delta-pyrrolines. In second part, we have reported the synthesis of new heterocyclic compounds with likely flavonoïd structures incorporating a quinoline unit, from the corresponding 2-hydroxy and 2-aminochalcones. These intermediates were utilized for the preparation of some new compounds that have a similar structure of flavanones, flavonols, 3-hydroxy-2,3-dihydroquinolin-(4)-ones. A new synthetic approach concerning the preparation of 1,2,3,4-tetrahydroquinolin-(4)-one derivatives through an intramolecular cyclization using a microwave irradiation have used with success
Moreau, Anne Madeleine. « Synthèse de produits naturels articulés autour du noyau isoindolinone ». Lille 1, 2004. http://www.theses.fr/2004LIL10023.
Texte intégralBrajeul, Solenn. « Produits naturels terpenoïdes dérivés d'acylphloroglucinols : travaux exploratoires en vue de la synthèse du xanthochymol et de ses analogues ». Paris 11, 2005. http://www.theses.fr/2005PA112288.
Texte intégralXanthochymol and guttiferones E and F are polyisoprenylated acylphloroglucins which inhibit the desassembly of miciotubules into tubulin. We have a project of total synthesis of these molecules using biogenesis hypothesis. Firstable, some studies about biomimetic synthesis have been done. Preparation of benzoylphloroglucinol has been studied. Then, prenylation under mild conditions using sulfonium salts have been studied. Finally some original electrophilic aromatic substitution have been developped using these salts. In a second part, the construction of the bicyclic moiety has been studied which has given several prenylated intermediairies. The synthesis of a polyprenylated β-ketoester has allowed the study of several methods to synthesize the bicycle. We observed great difficulties to get the bicycle due to the important steric hinderance mostly due to the gem-dimethyle. The synthesis of a diprenylated cyclohexanone should be usefull for the next studies. Finally the activity towards assembly or disassembly of microtubules has been studied for all the intermediary compounds
Billaud, Célia. « Approche synthétique de la norbadione A : nouvelle préparation d'alcools à partir de sulfones et de dérivés borés ». Paris 11, 2005. http://www.theses.fr/2005PA112222.
Texte intégralThe synthetic approach of norbadione A, a pigment from mushrooms related to pulvinic acids, was studied. This compound has the property to complex caesium and has shown an antioxidant activity. The first strategy, based on a double Suzuki-Miyaura coupling between a naphtholactone with two boron functions and two pulvinic moieties with a triflate was unsuccessful and has shown a deactivating effect of the lactone. Modifications aimed to inhibit the electro-attracting character of the lactone permitted to obtain a bis(coupled) product with a poor yield. A second approach based on a the cyclisation of enol arylacetates was studied in order to build the pulvinic moiety in several steps. The important reaction of introduction of an alkylacetate from a triflate was realised by a palladium-mediated coupling. The cyclisation attempts carried out using a naphthalenic compound allowed us to isolate a mono-cyclised product. A parallel study was to first build a tetronic moiety and then to construct the exocyclic double bond by a method developed in the laboratory for the preparation of an iodated pulvinic compound. Finally, a new preparation of alcohols from sulfones and boron compounds was developed. Two known reactions in the chemistry of boron were combined. The first one is the reaction between anions of sulfones and trialkylboranes, the second one is a thermal isomerisation which places the boron atom in a terminal position. A new preparation of primary alcohols was thus carried out
Rys, Véronique Angélique. « 1(2H)-isoindolinones, points d'ancrage pour l'élaboration de produits naturels et-ou à activité biologique ». Lille 1, 2003. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2003/50376-2003-163.pdf.
Texte intégralJida, Mouhamad. « Réaction de kulinkovich sur des esters dérivés d'aminoacides naturels et non naturelsApplication à la synthèse de précurseurs potentiels de produits biologiquement actifs ». Paris 11, 2008. http://www.theses.fr/2008PA112126.
Texte intégralThis thesis is devoted to the study of the intramolecular Kulinkovich cyclopropanation of esters prepared from natural and unnatural aminoacids. The reactions were performed with Grignard reagents in the presence of catalytic or stoechiometric amounts of titanium isopropoxide. The first chapter shows the scope of the Kulinkovich reaction which allows the transformation of esters into cyclopropanols. The reactions were carried out in both inter and intramolecular modes and are extended to cyclic carboxylic derivatives such as lactones, anhydrides, etc… In the second chapter, we study the regio and stereoselectivity of the cyclopropanation reaction when the starting materials possess two ester functions and a terminal double bond. The glutamate derivative furnished expected fused cyclopropanols while the aspartate derivative only gave unexpected pyrrolidinones. In the third chapter, the intramolecular cyclopropanation applied on other alphaaminoesters afforded expected bicyclic cyclopropanols as a mixture of diastereomers, thus providing an access to enantiomerically pure azabicyclo[3. 1. 0]hexanols. The fourth chapter concerns the reactivity of these alcohols under ring opening conditions. The different azabicyclo[3. 1. 0]hexanols were transformed into dihydropyridinones, pyrrolidinones, piperidones or pyridinols , possible precursors of bioactive products. Application of this methodology allowed the preparation of the (S)-2-phenylpiperidin-3-one , a potent intermediate in the synthesis of pharmacologically significant products (substance P antagonists)
Guillier, Fabrice. « Synthèse de produits naturels par association des réactions de métallation et de couplage. Accès à des alcaloïdes marins de type pyridoacridinique ». Rouen, 1996. http://www.theses.fr/1996ROUES075.
Texte intégralRanaivondrambola, A. Tsiresy. « Synthèse multi-étapes et synthèse parallèle de ligands nicotiniques potentiels : hybrides Anabasine-Lobéline et dérivés de la Sédamine ». Nantes, 2012. http://www.theses.fr/2009NANT2148.
Texte intégralWe have illustrated in this scientific production some technical aspects of drug discovery with natural substances chemistry and medicinal chemistry. The goal of our work to try bringing scientific contribution to the pharmacology of some targeted receptors, with the synthesis of innovative molecular concepts and ligands from natural piperidines moieties, of lobeline and sedum alkaloids. We then have materialized our efforts in verifying our hypotheses with the development of targeted natural analogues libraries which were biologically evaluated. Several practical techniques, described herein, were used such as linear and parallel synthesis
Sahmim, Wissem. « Modification chimique des extractibles de bois : application à la protection du bois et des matériaux métalliques ». Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0300.
Texte intégralWithin the framework of this thesis, we are interested in the design, synthesis and characterization of the physicochemical properties of lipophilic derivatives of wood extractives. We have thus considered modifying the structure of three flavonoids whose resource is important from different wood species: catechin, mesquitol and naringenin to incorporate additional functionalities. The applications reported here mainly deal with the protection of materials like wood and corrodible metals. With respect to wood preservation, it seems possible to consider different strategies to inhibit the wood degradation related to fungi on wood. Impregnation of antioxidant compounds such as lipophilic polyphenols on wood can limit the effects of radicals or other oxidants used and generated by rots. The second intended application is the protection of metallic materials. Indeed, the use of natural antioxidants as a corrosion inhibitor replace inorganic inhibitors or organic molecules (polyamines, imidazole...), because their production is expensive and toxic. The grafting of a hydrophobic hydrocarbon chain on polyphenols which have antioxidant properties allows the formation of protective films on the material
Jacques, Isabelle. « Découverte et déchiffrage de nouvelles voies de biosynthèse dépendant des synthases de cyclodipeptides : les clés d’une diversité accrue de dicétopipérazines potentiellement bioactives ». Thesis, Paris 11, 2015. http://www.theses.fr/2015PA114838/document.
Texte intégralDespite the interest and diversity of the pharmacological properties of 2,5-diketopiperazines (DKPs), the biosynthetic pathways of these microbial molecules are poorly documented. The aim of my doctoral work was i) to identify new DKP biosynthetic pathways that are characterized by the presence of a cyclodipeptide synthase (CDPS) often associated with one or more cyclodipeptide-tailoring enzymes and ii) to explore the chemical diversity encoded by these pathways. First of all, my study focused on CDPSs. After the bioinformatics-based selection of candidates, 51 novel CDPS were characterized, revealing the incorporation of 17 of the 20 proteinogenic amino acids. Moreover, this work has allowed a better characterization of the CDPS family, by showing the existence of several subfamilies with specific functional signatures and laying the foundations of a specificity conferring code for the synthesis of cyclodipeptides. Second, I characterized the tailoring enzymes associated with the newly identified CDPSs and, in particular, the Fe(II) and oxoglutarate dependent dioxygenases (OGs) that are highly represented in these pathways. I detected the in vivo activity for 11 OGs and characterized the in vitro activity for one of them, showing the complexity of the chemical modifications introduced into the cyclodipeptide. This work has led to identify and characterize novel biosynthetic pathways that provide access to a greater diversity of DKPs
Ruggieri, Francesca. « Putting nature back into drug discovery : selection, design and synthesis of bioinspired chemical libraries for the discovery of new antibacterials ». Electronic Thesis or Diss., Université de Lille (2022-....), 2024. http://www.theses.fr/2024ULILS013.
Texte intégralNatural products (NPs) have declined in popularity since the introduction of synthetic small molecules several years ago. Many are the reasons behind this choice, such as difficulties in access and supply, complexities of NP chemistry and the advent of combinatorial chemistry. However, NPs offer many interesting properties compared to conventional synthetic molecules, which confer both advantages and challenges for the drug discovery process. Usually, NPs are characterized by a higher number of sp3 carbons and stereogenic centres, large scaffold diversity and structural complexity. With half of the drugs approved by the FDA since 1994 being NPs or hemisynthetic derivatives and the recent stagnation in new drug research and development, it is becoming more and more evident that NPs should be reintroduced in the drug discovery process as a source of inspiration.Therefore, many strategies are now emerging for the construction of nature-inspired chemical libraries, such as “top-down” and “bottom-up” strategies. In “bottom-up” approaches, complexity is created starting from simple building blocks. On the other hand, “top-down” approaches are assumed to make structural modifications to an already complex NP.Our presented work describes two different approaches to enrich the chemical library of our research unit with NP-derived compounds. A “top-down” semisynthetic strategy was planned to obtain derivatives of lactucin and 11β,13-dihydrolactucin, two sesquiterpene lactones extracted from chicory roots. Thirty-six ester derivatives were synthesized in three steps (classical synthesis), together with two amine derivative libraries (using parallel synthesis). All the compounds were then tested against Mycobacterium tuberculosis and some promising hits were found (MICGFP < 1.2 μM). On the other hand, a “bottom-up” strategy allowed the synthesis of two analogues of the known natural antibiotic hygromycin A. This approach started from simple commercially available building blocks and employed a dearomatization strategy in the synthetic process.Together, we explored a broader chemical space, increased the structural diversity of our chemical library and discovered new potential antibacterial hits. Moreover, this work paves the way for the discovery of new antibacterial targets
Sahmim, Wissem. « Modification chimique des extractibles de bois : application à la protection du bois et des matériaux métalliques ». Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0300/document.
Texte intégralWithin the framework of this thesis, we are interested in the design, synthesis and characterization of the physicochemical properties of lipophilic derivatives of wood extractives. We have thus considered modifying the structure of three flavonoids whose resource is important from different wood species: catechin, mesquitol and naringenin to incorporate additional functionalities. The applications reported here mainly deal with the protection of materials like wood and corrodible metals. With respect to wood preservation, it seems possible to consider different strategies to inhibit the wood degradation related to fungi on wood. Impregnation of antioxidant compounds such as lipophilic polyphenols on wood can limit the effects of radicals or other oxidants used and generated by rots. The second intended application is the protection of metallic materials. Indeed, the use of natural antioxidants as a corrosion inhibitor replace inorganic inhibitors or organic molecules (polyamines, imidazole...), because their production is expensive and toxic. The grafting of a hydrophobic hydrocarbon chain on polyphenols which have antioxidant properties allows the formation of protective films on the material
Remeur, Camille. « Synthèse et évaluation biologique de dérivés de la meiogynine A, un produit naturel, qui ciblent la restauration de l'apoptose ». Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS158.
Texte intégralApoptosis, or programmed death, is used by multicellular organisms to regulate tissue homeostasis through the elimination of useless or potentially harmful cells. One of the main apoptotic pathways is controlled by the Bcl-2 family of proteins. These proteins are divided into pro-apoptotic members (as Bak or Bid) and anti-apoptotic members (as Bcl-xL, Mcl-1 or Bcl-2). In some cancers, they are often overexpressed in many kinds of cancer or are involved in the resistance to chemotherapy. Targeting these proteins is a highly promising strategy for anticancer therapy that has emerged over the last decades. Our team underwent a bioassay-guided screening of various plants extracts. A few years ago, meiogynin A, a dimeric sesquiterpenoid was isolated from a Malaysian tree bark using a bioassay-guided screening. This compound is a natural bcl-xL and Mcl-1 inhibitor. Total synthesis of meiogynine A was developped by our team and the final step is a Diels-Alder cycloaddition reaction between a triene and a dienophile. Then, the synthesis of two anlogues was performed, where the cyclohexane is replaced by an aromatic, and they shown a good biological activity in vitro and in celullo. Nevertheless, the Diels-Alder reaction is very slow. In order to improve triene reactivity and to perform structure activity relationship in the south part of meiogynine A, the synthesis of various original chlorinated triene functionnalized in the aromatic was realised. Two differents dienophiles was synthesized in order to modify the east part of the molecule. Several analogues were obtained et were evaluated on Bcl-xL and Mcl-1 proteins.Also, preliminary studies on protein/ligand interaction was started by the synthesis of two photoactivable probes
Alber, Annette Veronika. « Phenolic 3-hydroxylases in land plants : biochemical diversity and molecular evolution ». Thesis, Strasbourg, 2016. http://hdl.handle.net/1828/7651.
Texte intégralGraduate
2017-08-31
Ingels, Aude. « Contribution à l’étude de la Sphaeropsidine A et de ses dérivés pour combattre certains cancers agressifs et en particulier, les mélanomes ». Doctoral thesis, Universite Libre de Bruxelles, 2019. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/294565.
Texte intégralDoctorat en Sciences biomédicales et pharmaceutiques (Pharmacie)
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Mallinger, Aurélie. « Synthèse de dérivés de l'acide tétronique et de l'acide pulvinique ». Phd thesis, Paris 11, 2008. http://www.theses.fr/2008PA112259.
Texte intégralSeveral mushrooms pigments, such as norbadione A and pulvinic acid derivatives, exhibit a remarkable antioxidant activity. In the course of this PhD thesis, we have been interested in the synthesis of these compounds, which could be used as protection agents against ionizing radiations. In this context, a novel access to tetronic acid derivatives has been developed from methyl arylacetates and hydroxyesters. The methodology allows the synthesis of several 3-aryltetronic acids and related heterocyclic compounds in one step. From one of these tetronic acid derivatives, three natural esters of pulvinic acids have been prepared straightforwardly and in good yields. With regards to norbadione A total synthesis, two routes have been envisioned. The first one consists in the application of the methodology developed for the synthesis of pulvinic acids. This work has allowed us to synthesise a key bis(tetronic) intermediate. The second route, for which the key step is a double Suzuki-Miyaura cross-coupling, has allowed to complete the first total synthesis of norbadione A
Motatu, Iulia-Alexandra. « Synthèse et évaluation des propriétés anticancéreuses de nouveaux dérivés de tétrahydro gbs carbolines ». Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209137.
Texte intégralLe cancer reste une maladie grave car il représente une des causes principales de décès dans les pays développés. Plus d'un tiers de cancers solides réagi très faiblement à la chimiothérapie conventionnelle et/ou développe rapidement une résistance au traitement. Des thérapies ciblées, utilisées en association avec les traitements conventionnels, pourraient augmenter la survie des patients. C’est dans le cadre des thérapies ciblées que ce travail de thèse s’inscrit.
Nous nous sommes intéressés à synthétiser de nouvelles molécules qui pourraient être efficaces contre les cancers résistants à l'apoptose et donc aux traitements conventionnels. La principale cible de notre projet était la kinase DYRK1A, qui a été décrite comme étant impliquée dans la prolifération cellulaire et la résistance à l'apoptose. Dans ce but, une série de nouvelles molécules, principalement des dérivés de la tétrahydro-β-carboline, a été synthétisée et leurs propriétés antitumorales ont été caractérisées in vitro. En effet, ces structures ressemblent à celle de l’harmicine, un alcaloïde apparenté à l’harmine, l’inhibiteur de DYRK1A le plus sélectif et le plus puissant connu à ce jour.
Une méthodologie "one-pot" très efficace, développée au Laboratoire de Chimie Organique (ULB), a été utilisée pour obtenir les squelettes de type tétrahydro-β-carboline. Le deuxième chapitre de cette thèse détaille cette méthodologie et décrit la librairie de 47 dérivés qui ont été synthétisés.
Un second objectif de ce travail était de développer une version énantiosélective de cette méthodologie afin de la rendre encore plus intéressante. Cette partie, décrite dans le troisième chapitre, a été réalisée avec succès en collaboration avec l’Unité de Recherche en Chimie Organique et Macromoléculaire de l'Université du Havre (Le Havre, France). Les expériences que nous avons réalisées ont permis, non seulement d'obtenir le composé le plus actif avec un bon excès énantiomérique, mais également de mieux comprendre les aspects mécanistiques qui constituent la base de l'énantiosélectivité.
L'évaluation des propriétés anticancereuses des composés synthétisés est ensuite détaillée dans le quatrième chapitre. Les analyses toxicologiques et pharmacologiques ont montré que trois molécules présentent une bonne activité antitumorale in vitro avec une sélectivité prometteuse entre les cellules cancéreuses et les cellules normales. D’une manière inattendue, les tests biologiques plus poussés, que nous avons réalisés, ont suggéré que ces molécules n'agissent pas comme des inhibiteurs de kinases. Elles interfèrent en fait sur la prolifération cellulaire, en ciblant des facteurs de transcription spécifiques, par des mécanismes qui doivent encore être élucidés. Ces expériences biologiques ont été réalisées en collaboration avec le Laboratoire de Toxicologie et Cancérologie Expérimentale (ULB).
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Summary
Cancer is a devastating disease which remains one of the major causes of death in developed countries. More than one third of adult solid cancers respond very poorly to chemotherapy and/or rapidly develop resistance to treatment. Targeted therapies, used in combination with conventional treatments could be used to increase the survival of cancer patients.
In this work we were interested in developing new molecules related to the targeted therapy concept that could be effective against cancer types that are resistant to apoptosis and thereby to conventional treatments. The leading target of our project was the DYRK1A kinase, which was described as being involved in cell proliferation and resistance to apoptosis. For this purpose, a series of new molecules, mainly tetrahydro β carboline derivatives, has been synthesized and their antitumoral properties were characterized in vitro. Indeed these structures resemble harmicine, an alkaloid similar to harmine, the most selective and potent DYRK1A inhibitor known to date.
An efficient “one-pot” methodology, developed in the Laboratoire de Chimie Organique (ULB) was used to obtain the tetrahydro β carboline scaffolds. Chapter II of this work describes the use of this methodology for the synthesis of a library of 47 derivatives.
A second goal of this work was to further improve this methodology by developing an enantioselective version. This part, described in chapter III, was carried out successfully in collaboration with the Research Unit in Macromolecular and Organic Chemistry of Université du Havre (Le Havre, France). The experiments we have performed enabled us not only to obtain the most active compound with a good enantiomeric excess, but also to gain insight of the mechanism responsible for the enantioselectivity.
The fourth chapter details the evaluation of the anti cancer properties of the synthesised compounds. The pharmacological and toxicological analyses showed that 3 molecules display actual anti-tumor activity in vitro with a promising selectivity between cancerous and normal cells. Surprisingly, further biological assays we have performed suggested that these molecules do not act as kinase inhibitors but influence cell proliferation through the targeting of specific transcription factors by mechanisms that remain to be deciphered. The biological experiments were performed in collaboration with the Cancerology and Experimental Toxicology Laboratory (ULB).
Doctorat en Sciences
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Grandcoin, Alexis. « Sous-produits de dégradation d'herbicides dans le milieu naturel et sur les filières de traitement des eaux : quelles origines, quels impacts et quelles solutions ? » Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1B022/document.
Texte intégralAbstract : Brittany (France) is an agricultural region, where emerging pollutants are highly at risk to reach surface waters. Legal monitoring shows that herbicides metabolites are the main pollution of surface waters, in a region where 80 % of drinking water is produced with surface waters. The environmental behavior of herbicides metabolites is badly known and, for some of them, the contributions of their different sources are still debated. In east Britany, the Vilaine watershed (10 500 km²) is of great research interest, as a large drinking water treatment plant (100 000 m3/day) is located at the extreme downstream of it. In this context, this study aims to (i) map the watershed, (ii) evaluate the contamination and its spatial and seasonal variations, (iii) understand the favoring conditions resulting in metabolites export towards surface water, (iv) study sources and fate of AMPA (aminomethylphosphonic acid) in wastewaters, (v) explore ozonation treatment of a resistant metabolite in drinking water This thesis consists of three chapters: a review of the literature on herbicides and their metabolites occurrence and fate in surface waters, wastewaters, and drinking water; the materials and methods including, selection of compounds of interest, sampling strategy, description of the methods of analysis and quality assurance, statistical tools; the results of herbicides metabolites occurrences and behavior in the different waters studied. This work concludes on a broader context by providing perspectives to gain a better understanding of the sources and the factors influencing herbicides metabolites occurrences in the different waters, in order to improve the quality of water resources
Mai, Thi Trang. « Cell death mechanisms of Marmycin A and Salinomycin in cancer cells ». Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS014.
Texte intégralA natural product Salinomycin (SAL) is widely used as an anticoccidial drug now being increasingly recognized as an agent for reducing the proportion of CD44⁺/CD24⁻ breast cancer stem cell which is perceived as important factor for breast tumor relapse. We first time report that not ionophoric action but the proton “sponge” of SAL is responsible for distinguishingly targeting cancer stem cell population. In addition, one SAL-analog alkyne-amine performed the similar action with SAL on CD44⁺/CD24⁻ population but at much lower concentration than SAL, at 30 nM compare to 500 nM of SAL. Using click-imaging method we visually observed the colorless compound saturated in lysosomes and autolysosomes. By raising pH of acidic vesicles, SAL and its analogs inhibit cathepsin B, L, D activity preventing the autophagy which plays an important role in cancer stem cell maintain and survival thus lead to cell death via increasing ROS and apoptosis. Our study provides the insight mechanism how SAL actually eradicates cancer stem cells and suggests sharpened strategies for treating resistant cancers