Gold nanoparticles (AuNPs) have constantly attracted the attention of the scientific and industrial community due to the variety of physicochemical properties presented which are different and considered new properties from those that are evidenced in their mass form. Those new properties are strongly related to their morphology, providing a wide range of possible applications in several areas such as optics, medicine and catalysis. As well known, nanoparticles are thermodynamically unstable and consequently they have an easy tendency to agglomarate. In this context, the synthesis of nanoparticles in a general procedure, in particular the metallic ones, and more particularly the gold ones, need synthesis strategies with adequate growth control in the dynamics formation. Therefore, it becomes a constant challenge to obtain nanostructured materials with high yields and degree of selectivity. Among the various preparation methodologies, the seed-mediated method, seeding, is most commonly used, classically in the presence of Cetyltrimethylammonium bromide (CTABr) as a growth-driving agent. The obtained AuNPs were characterized by Visible Ultraviolet Absorption Spectroscopy (UV-vis) and Electron Transmission Microscopy (MET). These nanoparticles were evaluated in catalytic tests in chemical reduction reactions of p-Nitrophenol, where we investigated the influence of different reaction conditions such as the concentration of the catalyst, the reducing agent, and the optimum concentration and temperature variation. Surfactants were characterized by Ultraviolet Absorption Spectroscopy (UV-vis). Among the catalytic tests, the concentration of the reductant (NaBH4) was decreased from 0.1 mol L-1 to 0.05 mol L-1, 0.025 mol L-1 and 0.0025 mol L-1, between these concentrations, the molar ratio of the substrate/reductant was decreased from 500 to 12.5. The lowest borohydride concentration, 0.0025 mol L-1, gives a longer time to 100% conversion of p-nitrophenol, thus conducting studies varying the temperature of the system, in order to optimize the conversion time. herefore, the reaction was evaluated at temperatures of 25, 35, 45 and 55 °C, observing that with the increase of temperature, the reaction time of the reaction decreased. The reactions had a kinetic profile of pseudo-first order, so the apparent velocity constant was calculated for each reaction and it was observed that the reactions catalyzed by gold nanobastones (AuNRs) had a higher rate constant when compared to gold nanospheres (AuNSs). Finally, the activation energy (Ea) of the system was calculated, where Ea for reactions catalyzed by AuNRs was 70.5 kJ mol-1 and AuNSs obtained 105 kJ mol-1. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As nanopartículas de ouro (AuNPs) tem atraído constantemente a atenção da comunidade científica e industrial devido à variedade de propriedades físico-químicas apresentadas que são diferentes e consideradas novas das que são evidenciadas em sua forma mássica. Tais novas propriedades estão fortemente relacionadas à sua morfologia, proporcionando um grande leque de possíveis aplicações em diversas áreas como em óptica, medicina e catálise. Como se sabe, as nanopartículas são termodinamicamente instáveis e por isso possuem uma fácil tendência de se aglomerarem. Dentro desse contexto, a síntese de nanopartículas de um modo em geral, em particular as metálicas e mais particularmente as de ouro, precisam de estratégias de síntese com controle adequado de crescimento na dinâmica de formação. Portanto, torna-se um constante desafio a obtenção de materiais nanoestruturados com elevados rendimentos e grau de seletividade, .Entre as diversas metodologias de preparação, o método mediado por semente, ou semeadura, é o mais comumente utilizado, classicamente na presença de brometo de cetiltrimetilamônio (CTABr) como um agente direcionador de crescimento. As AuNPs obtidas foram caracterizadas por Espectroscopia de Absorção no Ultravioleta Visível (UV-vis) e por Microscopia Eletrônica de Transmissão (MET). Posteriormente, estas mesmas nanopartículas foram avaliadas em testes catalíticos em reações de redução química do p-Nitrofenol, onde investigamos a influência de diferentes condições reacionais como a variação da concentração do catalisador, do agente redutor buscando uma concentração otimizada e variação de temperatura.As reações de reduçãoforam caracterizadas por UV-vis. Dentre os testes catalíticos, a concentração do redutor (NaBH4) foi diminuída, de 0,1 mol L-1 para 0,05 mol L-1, 0,025 mol L-1 e 0,0025 mol L-1, entre essas concentrações, a razão molar do substrato/redutor foi diminuída de 500 vezes para 12,5 vezes. A menor concentração de borohidreto, 0,0025 mol L-1, aprensenta maior tempo para 100% de conversão do p-nitrofenol, assim realizou-se estudos variando a temperatura do sistema, com o objetivo de otimizar o tempo de conversão. Portanto a reação foi avaliada nas temperaturas de 25, 35, 45 e 55 °C, observando que com o aumento da temperatura, o tempo de conversão da reação diminuiu. As reações apresentaram perfil cinético de pseudo-primeira ordem, portanto foi calculado a constante de velocidade aparente para cada reação e observou-se que as reações catalisadas por nanobastões de ouro (AuNRs) apresentavam maior constante de velocidade quando comparadas as nanoesferas de ouro (AuNSs). Por fim, calculou-se a energia de ativação (Ea) do sistema, onde a Ea para as reações catalisadas por AuNRs obteve valor de 70,5 kJ mol-1 e por AuNSs obteve 105 kJ mol-1.

O metabolismo do triptofano (TRP) se dá por três vias metabólicas: a via das quinureninas, a via serotonérgica e a via das triptaminas. A primeira gera quinurenina e uma gama de produtos secundários e contribui para os fenômenos de tolerância e imunoescape de células tumorais. A via serotonérgica leva à produção de neuromediadores e pode gerar melatonina. Há evidências de que compostos desta via podem controlar o crescimento tumoral. A via das triptaminas origina triptamina (TRY) e N-N-dimetiltriptamina (DMT) e representa a rota menos conhecida de degradação do TRP. Assim, investigamos a via das triptaminas em linhagens de melanoma humano SK-Mel-19 e SK-Mel-147. A expressão gênica das enzimas aminoácido aromático descarboxilase (DDC) e indoletilamina-N-metiltransferase (INMT), que convertem o TRP em TRY e DMT, respectivamente, foi determinada por PCR em tempo real. Os metabólitos desta via foram detectados por LC/MS no sobrenadante das culturas celulares. O teste da ferida (scratch test) e o ensaio clonogênico foram usados a fim de triar uma possível atividade antitumoral de TRY e DMT. Apesar de termos observado a expressão das enzimas DDC e INMT apenas na linhagem SK-Mel-147, ambas produziram triptaminas e metabolizaram TRY e DMT. Dependendo da linhagem houve a produção de ácido indolacético, DMT hidroxilado e produtos de abertura do anel indólico. Por fim, TRY e DMT diminuíram a migração e a proliferação das células tumorais. Há ainda muito a se estudar sobre a participação da TRY e DMT na biologia do tumor e as nossas descobertas ampliam o papel do metabolismo do triptofano no processo tumoral. / Tryptophan (TRP) metabolism occurs by three pathways: kynurenine, serotonergic and tryptamines paths. The first generates kynurenine and a range of secondary products and contributes to tolerance and tumor immune escape. Serotonergic pathway leads to the production of neuromediators and can generate melatonin. There are evidences that compounds of this pathway may control tumor growth. Tryptamines pathway originates tryptamine (TRY) and N, N-dimethyltryptamine (DMT) and represents the less-known route of TRP degradation. Thus, we investigated tryptamines pathway on human melanoma cell lines SK-Mel-19 and SK-Mel-147. Gene expression of the enzymes aromatic amino acid decarboxylase (DDC) and indoletilamina-N-methyltransferase (INMT), which convert TRP to TRY and DMT, respectively, was determined by real time PCR. The metabolites of this pathway were detected by LC/MS in cell culture supernatant. The scratch test and clonogenic assay were used to screen a potential antitumor activity for TRY and DMT. Although we have observed the expression of the enzymes DDC and INMT only on SK-MEL-147, both cells produced tryptamines and metabolized TRY and DMT. Depending on the cell line, products were indoleacetic acid (IAA), hydroxylated-DMT (OH-DMT) and indole opening ring products. Finally, TRY and DMT decreased tumor cells migration and proliferation. There is much to be studied about the participation of TRY and DMT in tumor biology, and our findings extend the role of tryptophan metabolism in tumoral process.

In Saccharomyces cerevisiae nimmt die membrangebundene RING-Ub-Ligase Doa10 eine bedeutende Rolle in der Proteinqualitätskontrolle (PQC) des Endoplasmatischen Retikulums (ER) und des Nukleus ein. Doa10 katalysiert dabei die Verknüpfung K48- verbundener Ub-Ketten auf Proteine, die entweder in der ER-Membran oder löslich im Cytosol oder dem Nukleoplasma vorliegen. Diese Markierung leitet die Degradation dieser Proteine ein. Interessanterweise kooperiert Doa10, im Gegensatz zu anderen RING-Ub-Ligasen, mit zwei Ub-konjugierenden Enzymen (E2), um ihre Substrate zu prozessieren. In dieser Arbeit wird veranschaulicht, wie die beiden hochspezialisierten E2 Enzyme Ubc6 und Ubc7 sequentiell agieren, um Doa10 Substrate zu modifizieren. Zuerst wird ein einzelnes Ub-Molekül Ubc6-abhängig an ein Substrat konjugiert (Initiation). Von diesem Rest ausgehen katalysiert Ubc7 die Ausbildung einer K48-verbundenen Ub-Kette (Elongation). Die Fähigkeit von Ubc6 nicht nur Lysine, sondern auch hydroxylierten Aminosäuren wie Serin und Threonin mit Ub-Molekülen zu verknüpfen, erweitert das Substratspektrum von Doa10 und ermöglicht die Prozessieren von Proteinen, die keine zugänglichen Lysinreste exponieren. Weiterhin wird gezeigt, dass ein Überangebot von Ubc6 den Doa10-abhängigen Substratabbau beeinträchtigt. Dies weist darauf hin, dass die Generierung eines effizienten Poly-Ub-Signals einer streng kontrollierten Koordination beider E2 Enzyme am Doa10-Ligase-Komplex unterliegt. / In Saccharomyces cerevisiae, the membrane-bound RING-type Ub ligase Doa10 is a key player of Protein Quality Control (PQC) in the endoplasmic reticulum (ER) and the nucleus. Doa10 promotes lysine 48-linked poly-ubiquitylation of proteins that either reside in the ER membrane or are soluble in the cytosol or the nucleus and thereby labels them for degradation. Strikingly, in contrast to other RING Ub ligases, which typically employ a single Ub conjugating enzyme (E2) for substrate ubiquitylation, the Doa10 ligase requires two of such enzymes for client processing. This study demonstrates that the highly specialized E2 enzymes Ubc6 and Ubc7 act in a sequential manner on Doa10 client proteins. In a first step Ubc6 attaches a single Ub molecule to a substrate (priming), which is followed by the elongation of this moiety with K48-linked Ub chains by Ubc7 (elongation). The ability of Ubc6 to conjugate Ub not only to lysine but also to hydroxylated amino acids like serine and threonine broadens the substrate range of Doa10 and allows processing of proteins, which do not expose accessible lysine residues. Overproduction of Ubc6 was shown to impair Doa10 dependent substrate degradation. Apparently, the generation of a productive K48-linked poly-Ub signal requires a tightly coordinated activity of the individual E2 enzymes at the Doa10 ligase complex.

Le diabète de type 2 (DT2) est associé à un risque athéro-thrombotique élevé, en partie dû à l'hyperactivation plaquettaire et aux dyslipoprotéinémies. Les lipoprotéines de haute densité (HDL) possèdent des propriétés anti-athérogènes et subissent des modifications glycoxydatives lors du DT2. Notre objectif a été de déterminer les effets d'HDL glycoxydées in vitro ou de DT2 sur les plaquettes sanguines humaines et de déterminer leur contenu en lipides oxydés. Les HDL glycoxydées possèdent des proportions moindres d'acides linoléique et arachidonique dans les phospholipides (PL) et esters de cholestérol, des concentrations plus élevées de dialdéhyde malonique et des principaux acides gras hydroxylés (AGOH) dont les 9-HODE, 13- HODE et 15-HETE dans toutes les classes lipidiques, en particulier dans les PL ainsi que des concentrations très faibles de vitamine E comparativement aux HDL contrôles. Les HDL glycoxydées in vitro et de patients DT2 inhibent de façon dose-dépendante l'agrégation plaquettaire induite par le collagène via le récepteur SR-BI. Ces HDL glycoxydées diminuent la phosphorylation des p38 MAPK et cPLA2 plaquettaires. D'autre part, des HDL contrôles enrichies avec le PC(16:0/13-HODE) inhibent fortement l'agrégation comparativement aux HDL contrôles. De plus, les effets des sous-classes d'HDL, HDL 2 & 3, de DT2 et de témoins ont été testés sur l'agrégation plaquettaire. Les HDL2 de DT2 possèdent des concentrations d'AGOH plus élevées que les HDL3 de DT2 et tendent à inhiber plus l'agrégation plaquettaire. En conclusion, nos résultats montrent que les HDL glycoxydées de patients diabétiques ne perdent pas leurs propriétés anti-agrégantes, qui pourraient être médiées par certaines PL oxydés / Type 2 diabetes (T2D) is associated with a high athero-thrombotic risk, partly due to platelet hyperactivation and dyslipoproteinemia. High-density lipoproteins (HDL) possess antiatherogenic properties and undergo glycoxidation changes in T2D. Our objective was to determine the effects of glycoxidized HDL in vitro or from T2D patients on human blood platelets and to identify their oxidized lipid species. Compared to control HDL, glycoxidized HDL have lower proportions of linoleic and arachidonic acids in phospholipids (PL) and cholesteryl esters, higher concentrations of malondialdehyde and main hydroxylated fatty acid (HOFA) including 9-HODE, 13-HODE and 15-HETE in all lipid classes, especially in PL, and very low concentrations of vitamin E. In vitro glycoxidized and T2D HDL dose-dependently inhibit platelet aggregation induced by collagen via the SR-BI receptor. Glycoxidized HDL decrease the phosphorylation of platelet p38 MAPK and cPLA2. On the other hand, control HDL enriched with oxidized phospholipids i.e. PC(16:0/13-HODE) strongly inhibit platelet aggregation compared to controls. Moreover, the effects of HDL subclasses, HDL 2 & 3, from T2D patients and healthy controls were tested on platelet aggregation. T2D HDL2 have higher concentrations of HOFA than T2D HDL3 and tend to inhibit platelet aggregation to a greater extent. In conclusion, our results show that T2D glycoxidized HDL do not lose their anti-aggregatingproperties and are even more effective than control HDL. These anti-aggregatory effects could be partly due to some oxidized PL species

Polybrominated dibenzo-p-dioxins (PBDD) and dibenzofurans (PBDF) are a group of compounds of emerging interest as potential environmental stressors. Their structures as well as toxic responses are similar to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. High levels of PBDDs have been found in algae, shellfish, and fish, also from remote areas in theBaltic Sea. This thesis presents studies on PBDD behavior in fish and offspring, and natural formation of PBDDs from naturally abundant phenolic precursors. The uptake, elimination, and maternal transfer of mono- to tetraBDD/Fs were investigated in an exposure study reported in Paper I. The effects of PBDDs in fish were examined in a dose-response study (Paper II). It was shown that fish can assimilate PBDD/Fs from their feed, although non-laterally substituted congeners were rapidly eliminated. Laterally substituted congeners were retained as was congeners without vicinal hydrogens to some extent. PBDD/Fs were transferred to eggs, and congeners that were rapidly eliminated in fish showed a higher transfer ratio to eggs. Exposure to the laterally substituted 2,3,7,8-TeBDD had significant effects on the health, gene expression and several reproduction end-points of zebrafish, even at the lowest dose applied. The geographical and temporal variations of PBDD in biota samples from the Baltic Seasuggest biogenic rather than anthropogenic origin. In Paper III, bromoperoxidase-mediated coupling of 2,4,6-tribromophenol yielded several PBDD congeners, some formed after rearrangement. The overall yield was low, but significantly higher at low temperature, and the product profile obtained was similar to congener profiles found in biota from the Swedish West Coast. In Paper IV, photo­chemi­cally induced cyclization of hydroxylated polybrominated diphenyl ethers under natural conditions produced PBDDs at percentage yield. Rearranged products were not detected, and some abundant congeners do not seem to be formed this way. However, the product profile obtained was similar to congener profiles found in biota from the Baltic Proper. Since the PBDD congeners found in biota have a high turn-over in fish, the exposure must be high and continuous to yield the PBDD levels measured in wild fish. Thus, PBDDs must presumably be formed by common precursors in general processes, such as via enzymatic oxidations, UV-initiated reactions or a combination of both. The presented pathways for formation of PBDDs are both likely sensitive to changes in climatic conditions.

Philosophiae Doctor - PhD / Energy storage technologies are rapidly being developed due to the increased awareness of global warming and growing reliance of society on renewable energy sources. Among various electrochemical energy storage technologies, high power supercapacitors and lithium ion batteries with excellent energy density stand out in terms of their flexibility and scalability. However, supercapacitors are handicapped by low energy density and batteries lag behind in power. Supercapatteries have emerged as hybrid devices which synergize the merits of supercapacitors and batteries with the likelihood of becoming the ultimate power sources for multi-function electronic equipment and electric/hybrid vehicles in the future. But the need for new and advanced electrodes is key to enhancing the performance of supercapatteries. Leading-edge technologies in material design such as nanoarchitectonics become very relevant in this regard. This work involves the preparation of vanadium pentoxide (V2O5), pristine and zinc doped lithium manganese silicate (Li2MnSiO4) nanoarchitectures as well as their composites with hydroxylated graphene (G-ol) and carbon nanotubes (CNT). / 2023-12-01

Les canaux potassiques sensibles à l’ATP (KATP) jouent un rôle primordial dans plusieurs processus cellulaires. La modulation de ces canaux par des molécules activatrices constituerait des applications pharmacologiques et médicinales très intéressantes. À cet effet nous avons conçu et synthétisé de nouvelles molécules hybrides cromakalim-diazoxide et diazoxide-amine/aminoacide. Nous avons également, évalué l’activité myorelaxante de ces composés sur l’aorte de rates. Les résultats obtenus ne montrent pas un effet myorelaxant significatif. Des études sur d’autres tissus, notamment les cellules β pancréatiques et le muscle utérin, sont envisagées afin d’explorer une éventuelle sélectivité tissulaire. Par ailleurs, les interactions protéine-protéine jouent un rôle fondamental dans presque tous les processus cellulaires. Elles sont fortement impliquées dans la formation de la structure dimérique de la protéase du VIH-1 et l’agrégation du peptide β amyloïde impliquée dans la maladie d’Alzheimer. L’inhibition de ces interactions serait donc d’un avantage thérapeutique pour le traitement du SIDA et de la maladie d’Alzheimer. Nous avons conçu et synthétisé d’une part, des pinces moléculaires à base de motifs carbonylhydrazides et oligohydrazides (Azatide), et d’autre part, des molécules pentapeptidiques avec un peudoaminoacide central alcoolfluoré. Enfin, nous avons testé la capacité des pinces moléculaires à perturber le feuillet β terminal de la PR du VIH-1 afin d'inhiber sa dimérisation et donc son activité. Nous avons réalisé de même une étude de relation structure-activité et d’après l’ensemble des résultats obtenus, il semblerait que la flexibilité est délétère pour l’activité inhibitrice. Nous avons également évalué la capacité des nouvelles molécules peptidomimétiques alcool fluorées à accélérer ou inhiber l’agrégation du peptide Aβ1-42 dans le but de diminuer la présence de petits oligomères neurotoxiques. Les résultats obtenus sont très prometteurs, nous avons réussi à développer d’une part un pentapeptide capable d’inhiber totalement l’agrégation de Aβ1-42, et d’autre part des pseudopentapeptides capables d’accélérer son agrégation. Nous avons aussi démontré l’influence de l’atome de fluor sur la structuration d’un pentapeptide. Des études par RMN et DC sont en cours. / ATP-sensitive potassium channels (KATP) play an important role in many cellular processes. The modulation of these channels by activating molecules may constitute very interesting pharmacological and medicinal applications. For this purpose, we have designed and synthesized new hybrid molecules cromakalim-diazoxide and diazoxide-amine/aminoacid. We also evaluated the relaxant activity of these compounds on aorta of rats. The obtained results do not show a significant relaxant effect. Studies on other tissues, including pancreatic  cells and uterine muscle, are envisaged to explore the potency of these compounds and their possible tissue selectivity.Otherwise, Protein-protein interactions play a fundamental role in almost all cellular processes. They are strongly involved in the formation of the dimeric structure of HIV-1 protease and β amyloid peptide aggregation involved in Alzheimer's disease. Inhibition of these interactions would be a therapeutic advantage for the treatment of AIDS and Alzheimer's disease. We designed and synthesized on one hand, molecular tongs based on carbonylhydrazide oligohydrazid (Azatide) fragments and in the other hand, pentapeptide molecules with a central fluorinated and hydroxylated aminoacid. Finally, we tested the ability of molecular tongs to disrupt the terminal β sheet of the HIV-1 PR to inhibit its dimerization and thus its activity. We have also conducted a structure-activity relationship study and According to the results it seems that flexibility is detrimental to the inhibitory activity. We evaluated as well the ability of new fluorinated and hydroxylated peptidomimetics to accelerate or inhibit the aggregation of Aβ1-42 peptide in order to reduce the presence of small toxic oligomers. The results are very promising that we succeeded in developing a pentapeptide able to completely inhibit the aggregation of Aβ1-42, and in the other hand pseudopentapeptides able to accelerate its aggregation. We also demonstrated the influence of fluorine on the structure of a pentapeptides. Studies by NMR and DC are in progress.

Dans ce travail, deux méthodes d'extraction multi-résidus de contaminants présents dans des sédiments ont été développées. Dans la première partie de cette étude, une méthode a été développée pour l’'extraction simultanée de deux familles de métabolites oxygénés d'hydrocarbures aromatiques polycycliques (HAP), les quinones et les HAP hydroxylés (OH-HAP). Une approche chimiométrique a permis de déterminer les paramètres influant sur l’extraction assistée par micro-ondes (MAE) et une zone de compromis a été trouvée pour extraire de manière optimale les deux familles de composés. Deux méthodologies d’analyses chromatographiques ont été développées et validées pour analyser les extraits, puis comparées, à savoir la chromatographie liquide haute performance couplée aux détections UV et fluorimétrique (HPLC-UV-Fluo) et la chromatographie en phase gazeuse couplée à un spectromètre de masse par impact électronique (CPG-SM). En CPG-SM, des réactions de silylation des OH-HAP et d’acétylation des quinones ont dû être mises au point, afin d’abaisser les limites de détection (LD), en particulier pour les ortho-quinones. En HPLC-UV-Fluo, les LD étaient plus faibles qu’en CPG-SM, surtout pour les OH-HAP détectés en Fluo et l'analyse était plus rapide, sans processus de dérivation; mais la détection n’étant pas sélective, l’identification des analytes s’est avérée hazardeuse. Le choix s’est donc porté sur la CPG-SM pour une analyse plus fiable des deux familles de composés de matrices sédimentaires naturellement contaminées. Dans la deuxième partie de ce travail de thèse, une nouvelle méthodologie d'extraction a été développée et validée, basée sur la dispersion en phase solide de la matrice solide (MSPD), capable d'extraire mais aussi de purifier l’échantillon, méthodologie par ailleurs simple et rapide. Deux familles de composés ont été extraits simultanément à partir de sédiments, les HAP et les polychlorobiphényles (PCB). Un certain nombre de paramètres ont été optimisés, tels la nature des agents dispersants, le temps de broyage, le volume et la nature du mélange de solvants d’élution. Dans un deuxième temps, l'introduction des OH-HAP dans le processus analytique a amené à coupler à la MSPD une autre méthode d’extraction/purification beaucoup plus sélective, basée sur les polymères à empreintes moléculaires (MIP). En effet, les interférents polaires, restés piégés par l’agent dispersant polaire dans la première cartouche contenant le sédiment broyé, devaient être élués afin de libérer les OH-HAP, qui a leur tour devaient être retenus sélectivement dans un MIP empreint pour les phénols, pour fournir une élution finale exempte d'autres composés. Il a été montré que ces MIPs pouvaient extraire sélectivement les OH-HAP de faible et de haut poids moléculaire, mais il fallait choisir soigneusement le solvant de percolation pour ne pas endommager le polymère. Cependant, la difficulté principale a été de désorber les OH-HAP fortement retenus par le sédiment par liaison hydrogène. Cela a pu être réalisé pour les OH-HAP légers, en utilisant un mélange de solvants avec un effet de relargage par un sel, mais pas pour les OH-HAP lourds, trop fortement adsorbés sur la matrice sédimentaire. Par ailleurs, il a fallu utiliser une grande quantité de polymère à empreinte moléculaire à cause de la compétition pour les sites de reconnaissance entre les OH-HAP et des composés phénoliques. / In this work two multiresidual methods for extracting contaminants from sediments were developed. In the first part of this study, a method was developed for extracting simultaneously two groups of oxygenated metabolites of polycyclic aromatic hydrocarbons (PAHs), quinones and hydroxylated PAHs (hydroxy-PAHs). A chemometric approach allowed us to determine the influential parameters on microwave assisted extraction (MAE), and a compromise could be found for extracting quantitatively both families of compounds. Two chromatographic analytical methodologies were developed and validated for analysing the extracts: high performance liquid chromatography coupled with fluorimetric and ultraviolet detection (HPLC-UV-FLD) and gas chromatography coupled with an electronic impact mass spectrometer (GC-MS). Using GC-MS, reactions of silylation of hydroxy-PAHs and of acetylation of quinones had to be developed, to decrease detection limits (LOD), particularly for ortho-quinones. Using HPLC-UV-FLD, LODs were lower than using GC-MS, particularly for hydroxy-PAHs detected by FLD, and the analysis was faster, without derivatization; but the detectors were not selective, and identification of analytes was doubtful. Choice was done to favour GC-MS for a more reliable analysis of the two families of compounds extracted from naturally contaminated sediments. In the second part of this thesis work, a new fast and simple extraction methodology was developed and validated, based on matrix solid phase dispersion (MSPD), capable of extracting and purifying simultaneously sediment samples. Two families of compounds were simultaneously extracted from sediments, PAHs and polychlorobiphenyls (PCBs). Many parameters were optimized, as the nature of dispersing agents, the time of grinding, the volume and nature of elution solvent mixtures. In a second step, hydroxy-PAHs were introduced in the analytical process, which led us to add another more selective extraction/purification method to MSPD, based on molecularly imprinted polymers (MIPs). Indeed polar interfering compounds, trapped by the polar dispersant in the first cartridge containing the blended sediment, had to be eluted to release hydroxy-PAHs, which in turn had to be selectively retained by the polymer, imprinted for phenols, to provide a final eluate free from other polar compounds. It was demonstrated that those MIPs could selectively extract low and high molecular weight hydroxy-PAHs, but appropriate percolating solvents had to be chosen to avoid polymer damages. However, the main difficulty was to desorb hydroxy-PAHs strongly retained by the sediment matrix through hydrogen bonds. It could be achieved for light hydroxy-PAHs, using a mixture of eluting solvents with salting-out effect, but not for heavy hydroxy-PAHs which stayed strongly sorbed on the sediment matrix. Furthermore we needed to use high amounts of imprinted polymer because of the competition for recognition sites between hydroxy-PAHs and phenolic compounds.