Dissertations / Theses on the topic 'Nucléotides – Synthèse (chimie)'
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Peltier, Pauline. "Nucléotides-sucrés furaniques : synthèses et activités anti-mycobactériennes." Rennes 1, 2008. http://www.theses.fr/2008REN1S098.
Full textFuranosides are original glycosides which are presents in several micro-organisms, particulary in pathogenic species, such as those responsible for tuberculosis, leprae, Chagas diseases. . . The fact that those glycoconjugates are absent in mammal makes those five-membered ring sugars, valuable targets to design new pharmacophores and/or treatments. Therefore, a better understanding of furanoconjugates 's biosynthetic pathways is a crucial step of this new therapeutic strategy. This report presents a straightforward chemical synthesis of nucleotides-sugars from thioimidoyl furanosides. Then, this work underlines also the biocatalytic behavior of nucleotidylyltransferases in order to synthesize non-natural furanosyl nucleotides. At last, activities of those new compounds were evaluated on the enzymes involved in the biosynthesis of the arabinogalactan of Mycobacterium tuberculosis
Diab, Sonia Amel. "Synthèse de difluorométhylphosphonates par voies ionique et radicalaire en vue de la préparation d'inhibiteurs de Thymidine phosphorylase." Caen, 2009. http://www.theses.fr/2009CAEN2054.
Full textThis thesis is devoted to the preparation of fluorinated compounds. In particular are reported new synthetic pathways analogues of phosphates and phosphonates with a difluorométhylphosphonate function. The first introductory chapter points out the general importance of phosphates in the living world. The use of the difluoromethylphosphonates as stable mimic of phosphate in physiological medium is highlighted. The various methods of difluorophosphonates synthesis are then displayed and grouped by categories. It highlighted the difficulties encountered in the different approaches, often limiting the application of these strategies. The third chapter discusses new ways of syntheses difluorophosphonates avoiding hydrohalofluorocarbures (HCFCs). Are reported the preparations of omega-hydroxy-difluoromethylphopshonates by ring opening reactions with the phosphonodifluoromethylanion. The reaction is performed with oxacycles, lactones, and cyclic sulfates. Some work is also devoted to radical addition reactions involving the radical phosphonodifluoromethyle. The last chapter is devoted to the preparation of enzyme inhibitors and evaluation of their activities. The main objective is to produce inhibitors of thymidine phosphorylase (TPase), an enzyme involved in tumor angiogenesis
Rycke, Nicolas de. "Nouveaux analogues de la DMAP : synthèse et réactivité." Versailles-St Quentin en Yvelines, 2011. http://www.theses.fr/2011VERS0024.
Full textCatalysts which act as Lewis bases show a growing interest because of their capacity to promote a significant number of transformations in organic synthesis. Specifically, since its discover at the end of the 1960’s, 4-(dimethylamino)pyridin (DMAP) has been studied and introduced to accelerate the rate of several reactions such as the acylation of tertiary alcohols. The reactivity of this derivative is sometimes limited with deactivated substrates leading to a very slow conversion in products. First, we were interested on the synthesis of tricyclic triaminopyridins, strong analogs of DMAP and their reactivity was studied with the determinations of kinetic N and Lewis parameters thermodynamic basicity. Secondly, we prepared a new class of chiral DMAP derivatives, the structure of which is included in a paracyclophanic backbone. In parallel to this work, we developed a new nucleophilic probe which was involved in the comparison of the reactivity of aziridinium and azetidinium towards nucleophiles, by measuring their ring opening rates by UV-visible and RMN 1H spectrophotometry. Finally, the last part of this pH. D. Work was about the design and the synthesis of organocatalytic cages. This kind of derivatives would encapsultate substrates within its cavity to promote chemical reactions like enzymes do, while avoiding their difficulties of use such as a limited stability under certain protocols
Akouche, Mariame. "Synthèse prébiotique de Ribonucléotides sur des surfaces minérales." Electronic Thesis or Diss., Paris 6, 2016. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2016PA066609.pdf.
Full textIn the « RNA world» prebiotic scenario, ribonucleotide polymers are considered as the first biochemical species to have emerged. However, in aqueous solution, their formation through conventional mechanisms of condensation is thermodynamically forbidden. Several synthesis pathways of nucleotides have been described in aqueous solution; most often, they involve chemically activated molecules. Another pathway to nucleotides implies mineral surfaces, which have been considered in prebiotic processes at least since the work of Bernal in 1951. However, these studies have hardly tried to understand surface-molecule interactions and consequently, thermodynamic and/or catalytic effects of mineral surfaces are not well rationalized. In the context of Bernal's hypothesis, we present for the first time an in-situ study of the thermal reactivity of nucleotides “building blocks” adsorbed on mineral surfaces (amorphous silica, saponite) emphasizing the synthesis of nucleotides without chemical activation. In our work, we first show that mineral surfaces are able to trigger the formation of inorganic polyphosphates from monophosphates at moderate temperatures. On the other hand, adsorption of ribose on silica surface improves its thermal stabilization. While ribose decomposes at 90°C in aqueous solutions, it is stable up to 200°C on silica (in the presence of ZnCl2). Secondly, we have demonstrated the formation of PRPP, as important reaction intermediate, by co-adsorption of ribose and inorganic phosphate on the silica surface. Finally, we showed the glycosylation of adenine to adenosine and the formation of AMP (i.e. simultaneous glycosylation and phosphorylation) after co-adsorption of their components on both mineral surfaces employed. A preliminary study even suggests that nucleotide dimerisation can occur in the same conditions
Appy, Lucie. "Nouvelles approches de synthèses de nucléotides et de leurs conjugués." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS047.
Full textThis thesis relates to the global problem of the synthesis of phosphorylated biomolecules, and in particular of nucleotides and their analogues (polyphosphorylated derivatives, liponucleotides, glyconucleotides…). Indeed, these derivatives, whether endogenous or synthetic, are widely used as biological tools. Some of these compounds also exhibit strong therapeutic potential, in particular in the field of antiviral or antitumor agents. The preparation of these polyphosphorylated derivatives however remains a technological challenge owing to the multiple tedious and expensive purification steps, often leading to modest to low yields.The primary objective of this work, lies in the development of new, efficient and/or eco-responsible synthetic methodologies of nucleotides derivatives. The first chapter of this manuscript corresponds to a non-exhaustive presentation of the methods described in the literature for the synthesis of various nucleotides, emphasizing their advantages and drawbacks. The second chapter concerns the development of a supported synthesis methodology of nucleotides and nucleotide analogues in the adenosine series. Finally, the last chapter describes a second new and eco-responsible methodology using a solvent-free approach
Le, Hir de Fallois Loic. "Synthèse et étude de nucléosides et nucléotides inhibiteurs de la ribonucléotide réductase." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10158.
Full textLoizeau, Karen. "Étude de la régulation du métabolisme monocarboné chez Arabidopsis thaliana." Grenoble 1, 2009. http://www.theses.fr/2009GRE10141.
Full textTetrahydrofolate (THF) derivatives, collectively termed folates or vitamin B9, are involved in almost all the metabolic processes that require the addition or removal of one-carbon units (C1 metabolism). C1-substituted folate coenzymes are thus involved in several major cellular processes, including the synthesis of nucleotides (purines and thymidylate) and amino acids (methionine, serine, glycine). Methionine serves as a methyl group donor through conversion to S-adenosylmethionine, the key biological methylating agent involved in dozens methyltransferase reactions. Plants, fungi and most micro-organisms are able to synthesize THF de novo whereas humans and animals in general lack this capacity and thus rely on dietary intake of vitamin B9. During plant development, the enzymatic capacity for THF synthesis, the pool of folates, and the demands for C1-units vary importantly. However, little is known about how folate homeostasis is controlled to match the supply of C1-units, and how C1-units are accurately distributed between the different anabolic routes. In this work, we identified different regulatory mechanisms that allow plants to respond to a limitation of the folate pool. First, we analyzed the genome-wide and metabolic response of Arabidopsis cells to folate depletion induced by the antifolate methotrexate. Surprisingly, no significant change in the expression of genes involved in cofactor synthesis, degradation or trafficking was observed. One major response to folate limitation concerned the composition of the cofactor pool. Thus, the transcriptional regulation of a limited number of genes coding enzymes manipulating C1-moieties in plastids was associated with a re-orientation of C1-units towards the synthesis of purines and thymidylate. These data suggest that the metabolic priority of Arabidopsis cells in response to folate limitation is to shuttle the available folate derivatives to the synthesis of nucleotides at the expense of methylation reactions. Second, because the efficiency of methylation reactions are likely affected by folate depletion, we investigated the relationships between the folate status, the methyl cycle activity, and the rate of chlorophyll synthesis, which relies at one step on a methylation reaction catalyzed by Mg protoporphyrin IX methyltransferase. Etiolated pea leaves treated with methotrexate displayed a reduced folate pool and a marked decrease in the methyl index. This resulted in a metabolic regulation (inhibition) of the Mg-protoporphyrin IX methyltransferase activity and to a decreased rate of chlorophyll synthesis. These results point out that an even moderate change in the folate status may affect essential physiological processes such as chloroplast biogenesis. Last, the analysis of Arabidopsis cells exposed to a long-term folate starvation revealed an original post-translational regulation of methionine synthesis. This process consists in the proteolytic cleavage of the N-terminal domain of cystathionine -synthase, the first specific enzyme for methionine synthesis. We suggest that an effector, to date unidentified, can modulate enzyme activity in vivo through an interaction with the N-terminal domain and that removal of this domain in folate-deficient cells can suppress this regulation
Akouche, Mariame. "Synthèse prébiotique de Ribonucléotides sur des surfaces minérales." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066609/document.
Full textIn the « RNA world» prebiotic scenario, ribonucleotide polymers are considered as the first biochemical species to have emerged. However, in aqueous solution, their formation through conventional mechanisms of condensation is thermodynamically forbidden. Several synthesis pathways of nucleotides have been described in aqueous solution; most often, they involve chemically activated molecules. Another pathway to nucleotides implies mineral surfaces, which have been considered in prebiotic processes at least since the work of Bernal in 1951. However, these studies have hardly tried to understand surface-molecule interactions and consequently, thermodynamic and/or catalytic effects of mineral surfaces are not well rationalized. In the context of Bernal's hypothesis, we present for the first time an in-situ study of the thermal reactivity of nucleotides “building blocks” adsorbed on mineral surfaces (amorphous silica, saponite) emphasizing the synthesis of nucleotides without chemical activation. In our work, we first show that mineral surfaces are able to trigger the formation of inorganic polyphosphates from monophosphates at moderate temperatures. On the other hand, adsorption of ribose on silica surface improves its thermal stabilization. While ribose decomposes at 90°C in aqueous solutions, it is stable up to 200°C on silica (in the presence of ZnCl2). Secondly, we have demonstrated the formation of PRPP, as important reaction intermediate, by co-adsorption of ribose and inorganic phosphate on the silica surface. Finally, we showed the glycosylation of adenine to adenosine and the formation of AMP (i.e. simultaneous glycosylation and phosphorylation) after co-adsorption of their components on both mineral surfaces employed. A preliminary study even suggests that nucleotide dimerisation can occur in the same conditions
Guiller, Alain. "Synthèse et réactivité de sulfites cycliques osidiques. Nouvelle méthode de glycosylation." Lyon, INSA, 1986. http://www.theses.fr/1986ISAL0036.
Full textDabeux, François. "Synthèse d'analogues de l'adénosine-5'-triphosphate, agonistes potentiels du récepteur P2Y11." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210498.
Full textLe premier objectif que nous nous sommes fixés au cours de notre thèse de doctorat fut de mettre au point un schéma de synthèse permettant d’obtenir des analogues de l’adénosine-5’-triphosphate [1] portant un motif thioalkyle ou thioaryle en position 2 de la base ainsi qu’un groupement dichlorométhylène entre les phosphores b et g &
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Aouf, Nour-Eddine. "Synthèse, structure et réactivité de sulfahydantoi͏̈nes dérivées d'aminoacides par insertion de sulfamoyle." Montpellier 2, 1994. http://www.theses.fr/1994MON20095.
Full textLemin, David. "Synthèse d'analogues des ligands naturels de récepteurs nicotiniques et purinergiques." Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211158.
Full textDans la première partie de cette thèse, nous avons réalisé la synthèse d’analogues de la 11-homosédinone, alcaloïde isolé de la plante Sedum acre, qui présente une activité agoniste sur différents récepteurs nicotiniques du système nerveux central. Les différents analogues ont été synthétisé par application de la méthoxylation anodique pour introduire succesivement deux substituants en postion 2 et 6 d’un noyau pipéridinique. Les analogues synthétisés se différencient par la nature du noyau aromatique, la présence d’un groupement méthyle sur l’atome d’azote de la pipéridine et l’oxydation du sustituant en position 2. Ce travail a notamment permis de montré l’importance du groupement N-méthyle vis-à-vis de l’activité des analogues. Nous avons également pu mettre en évidence que l’introduction d’un halogène sur le noyau aromatique diminuait l’activité de l’analogue sur le récepteur a7 tout en augmentant l’acitivité sur le récepteur a4b2 et que l’introduction d’un noyau furanique permettait d’augmenter la sélectivité vis-à-vis du récepteur a4b2 tandis que l’introduction sur le noyau aromatique d’un groupement nitro ou méthoxy conduit à une perte totale de l’activité.
Dans la seconde partie de cette thèse, nous avons réalisé la synthèse d’analogues de la dATP, afin d’évaluer leur effet agoniste sur le récepteur P2Y11, impliqué dans différents mécanismes de différentiation cellulaire, dont notamment celui de la maturation des cellules leucémiques HL60 en cellules de type neutrophile. Les analogues synthétisés se différencient de la dATP par la présence d’un groupement méthylène ou dichlorométhylène entre les phosphores b et g de la chaîne polyphosphate, ainsi que par l’estérification de l’alcool en position 3’ du sucre. Ce travail a pu confirmer que les analogues en série 2’-désoxy conduisent à de meilleures activités que ceux de la série 2’-OH. Nous avons également pu montrer que l’estérification de la position 3’ conduit à une diminution de l’activité agoniste, à l’exception du groupement a-naphtoyle qui conduit à une augmentation significative de l’activité sur P2Y11.
Doctorat en sciences, Spécialisation chimie
info:eu-repo/semantics/nonPublished
Pradere, Ugo. "Synthèse métallo-catalysée d'analogues de nucléosides et d'oxazolo[4,5-d]pyrimidines à visée thérapeutique." Phd thesis, Université d'Orléans, 2009. http://tel.archives-ouvertes.fr/tel-00665129.
Full textDepaix, Anaïs. "Contribution à l'étude et à la synthèse de biomolécules phosphorées en série nucléosidique." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT178.
Full textPhosphorylated derivatives of endogenous nucleosides or analogues (called nucleotides) are crucial compounds widely used as biological tools. Some of them also have a high therapeutic potential, in particular as antiviral or antitumor agents. However, the synthesis of polyphosphorylated derivatives of nucleosides remains a challenge due to low yields as well as long and tedious multiple purification steps. Thus, this manuscript is dealing with the overall problem of synthesis of these compounds. The first chapter is devoted to the non-exhaustive study of the synthetic methods described in the literature for such compounds, recalling the advantages and disadvantages of these approaches. In the second chapter, we report our contribution to an original synthetic pathway in aqueous media of some nucleotides and analogues. Some preliminary results of mecanosynthesis based on the same approach are also presented. Finally, the third chapter refers to supported synthesis of nucleotides with two different approaches. One involves cytidine and its anchoring on polyethylene glycol in order to provide the corresponding 5'-di- and triphosphate derivatives. The other concerns the development of a novel tetrapod support that may be valuable for the synthesis of adenosine derivatives
Mathieu, Thomas. "Etude de deux ANPs Antiviraux : caractéristiques physico-chimiques du LAVR-289 et formulations innovantes du Ténofovir." Electronic Thesis or Diss., Orléans, 2024. http://www.theses.fr/2024ORLE1021.
Full textThis thesis is part of one of the stages in the preclinical development of a drug candidate, which consists in determining various physico-chemical characteristics of the compound and exploring its formulation. The molecule in preclinical phase is LAVR-289, a novel broad-spectrum antiviral belonging to the acyclonucleoside phosphonate family, developed in prodrug form.We began by determining various parameters of LAVR-289 such as pKa, Log P and critical aggregation concentration by UV-visible spectrophotometry, reversed phase liquid chromatography and spectrofluorimetry, respectively. We also developed a HPLC-UV analytical method to determine the purity of LAVR-289 synthesis batches. This analytical method was used to determine the chemical stability of this molecule with respect to solvents and pH, as well as its plasma enzymatic stability. LC-HR-MS analyses were used to obtain the structure of degradation products and some metabolites. In the second part, we have synthesised new polymeric nanocarriers based on molecular imprinting technology for the controlled release of phosphonate acyclonucleosides. This exploratory study was carried out on Tenofovir, an antiviral used in the treatment of HIV and HBV infections. These nanomaterials were developed by precipitation polymerisation or by creating core-shell systems after surface derivatisation of biodegradable and biocompatible nanoparticles synthesised in the laboratory. These polymers were created from monomers derived from the functionalisation of pyrimidine bases. These materials showed slower temperature-dependent release kinetics of Tenofovir than the no imprinted form
Berrada, Sara. "Synthèse de dérivés génotoxiques permettant la quantification des pontages interbrins et l’identification de défaut de réparation chez le patient atteint de l’anémie de Fanconi." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0145.
Full textInter-strand crosslink (ICL) are formed by covalent link between two nucleotides located on opposite strands of DNA. This physical link blocks the replication and transcription mechanisms. Because of this mode of action, BIPs-inducing agents are highly toxic to abnormally proliferating cells, which makes them very effective drugs for the treatment of cancers. However, their use is limited by the occurrence of severe side effects resulting in organ failure due to excessive accumulation of ICLs. This may be caused by insufficient repair capacity which will result in healthy cell death upon exposure to ICLs and organ failure.In order to identify the origin of insufficient repair in these patients, a comprehensive knowledge of ICLs repair is required. To date, many repair pathways have been described, but steps in the repair process are still unknown. A direct detection of ICLs would allow to answer these questions. However, the currently available techniques suffer from various limitations and a direct detection of ICLs, at the cellular level and/or in organs, is challenging.During my thesis, I modified two ICLs inducing agents. One is currently used in chemotherapy and the second one has completed a phase II clinical trial. I demonstrated that these modified agents show unchanged cytotoxicity and ability to induce ICLs compared to unmodified agents. I validated their detectability by microscopy as well as by FACS and demonstrated that they could be used to measure ICL repair in different cell lines
Trévisiol, Emmanuelle. "Synthèse de nucléotides triphosphates modifiés pour le diagnostic moléculaire par reséquencage sur puces à ADN." Grenoble 1, 1999. http://www.theses.fr/1999GRE10274.
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