A presente tese relata, em sua primeira parte, o estudo de reatividade das reações competitivas de Michaelis-Arbuzov e Perkow de algumas &#945-haloacetofenonas-orto e meta-substituídas [o- e m-Y-&#934-C(O)CH2-Hal] (Hal = CI, Br e I; Y = OMe, Me, H, F, CI, Br e NO2) com o trietilfosfito. Estas reações foram acompanhadas por cromatografia a gás e observou-se que no caso das reações das &#945-bromoacetofenonas-meta-substituídas as proporções dos produtos de Michaelis-Arbuzov e Perkow, cetofosfonato e enolfosfato respectivamente, estão diretamente relacionadas à constante &#963m, enquanto que nas &#945-cloro e &#945-iodoacetofenonas-orto-substituídas não foram observados os efeitos dos substituintes. Entretanto, nas &#945-bromoacetofenonas- orto-substituídas, verificou-se uma forte dependência da constante &#963I dos substituintes com as proporções relativas dos produtos formados. Na segunda parte desta tese, foi realizado um estudo conformacional de 7 séries de &#945-heteroacetofenonas-orto e meta-substituídas [o- e m-Y-&#934-C(O)CH[X]-P(O)(OEt)2] (X = H, SMe, S(O)Me e SO2Me; Y = OMe, Me, H, F, CI, Br e NO2), através da espectroscopia no infravermelho apoiada por cálculos ab initio HF/6-31 G**. Foi observada, para a maioria dos casos, a presença de um ou dois confôrmeros em solução, onde na maioria dos casos a conformação mais estável é a gauche (sin-clinal) e a segunda mais estável é ou cis (sin-periplanar) ou gauche (anti-clinal). Na série das &#945-metiltio-&#945-dietoxifosforilacetofenonas-orto-substituídas não foi possível efetuar o estudo conformacional devido a enolização presente nestes compostos. Nas &#945-metilsulfinil-&#945-dietoxifosforilacetofenonas-meta-substituídas verificou-se através das espectroscopias no infravermelho e ressonância magnética nuclear, a presença de um equilíbrio diastereomérico. / This thesis reports the study of the reactivity of the competitive Michaelis- Arbuzov and Perkow reactions of some orto- and meta- substituted &#945-haloacetophenones (I) [o- and m-Y-&#934-C(O)CH2-Hal] (Hal = CI, Br e I; Y = OMe, Me, H, F, CI, Br and NO2) with triethyl phosphite, by gas chromatography, and the conformational analysis of some orto- and meta-substituted &#945-heteroacetophenones (II) [o- and m-Y-&#934-C(O)CH[X]-P(O)(OEt)2] (X = H, SMe, S(O)Me and SO2Me; Y = OMe, Me, H, F, Cl, Br and NO2), by means of infrared spectroscopy and ab initio HF/6-31 G** computations. For reactions involving meta-substituted &#945-bromoacetophenones and triethylphosphite it was found a good correlation between the ketophosphonate / enolphosphate ratio (K/E) and the &#963m constant. The (K/E) ratios obtained from the reaction of the orto- substituted &#945-chloro- and &#945-iodo-acetophenones and triethylphosphite did not show a clear trend with any substituent constant. However, a good correlation between the (K/E) ratio and the &#963I constant was obtained in the case of the reaction involving the orto-substituted &#945-bromoacetophenones and triethylphosphite. The vco infrared analysis in general compares well with the ab initio calculations which showed the occurrence of one or two stable conformations for compounds of series (II), being the gauche (syn-clinal) the most stable and the cis (syn-periplanar) or the gauche (anti-clinal) the second one. The vco IR analysis of the orto-substituted &#945-methylthio-&#945-diethoxyphosphorylacetophenone series was precluded due to its strong enolization. As for the meta-substituted &#945-methylsulfinyl-&#945-diethoxyphosphoryl-acetophenones the IR and NMR spectroscopies along with the ab initio computations showed the ocurrence of a diastereomeric equilibrium both in gas and in solution.

In the present thesis we propose the development of hybrid polymer titanium dioxide (TiO2) nanoparticles for use in biomedical applications. TiO2 exhibits high biocompatibility in the dark however, upon illumination in aqueous media with near UV light it produces an array of reactive oxygen species (ROS) which have the capability to induce death in neighbouring cells. The process of inducing cell death using a photosensitive material which produces ROS is known as photodynamic therapy (PDT) and is used to treat a wide range of maladies from psoriasis to cancer.We have demonstrated the ability to produce anatase nanoparticles with high control over their resulting size through a novel water mediated sol-gel synthetic method in benzyl alcohol, using either Ti(OnPr)4, Ti(OnBu)4 or Ti(OiPr)4 as the metal precursor. Through dynamic light scattering (DLS) analysis we have shown that the mechanism of nanoparticle growth appears to proceed through the agglomeration of primary nanoparticles formed instantly upon adding the reagents together. After synthesis the nanoparticles could be easily redispersed in aqueous media at pH2 with any further agglomeration being controlled by the parent alkoxide.After synthesis the nanoparticles were coated with PEG, conjugated to either a catechol or phosphate as ligand, in order to stabilise the nanoparticles at neutral pH. Uncoated nanoparticles exhibited good photoactive capability in the photooxidation of methylene blue. However, on coating with catechols the photoactivity of the nanoparticles was abolished. Coating with phosph(on)ates on the other hand preserved or even enhanced the photoactivity which makes this system promising for in vivo applications.At the same time this thesis also reports preliminary investigations on the use of TiO2 embedded into the walls of model drug loaded poly electrolyte multilayer microspheres for UV triggered delivery applications.

First part of this thesis was focused on the previously overlooked field of C1'-branched acyclic nucleoside phosphonates (ANPs). Five diverse synthetic approaches were developed/optimized affording key 6-chloropurine intermediates bearing N9 -phosphonomethoxyethyl (PME) branched at C1' position in 2-4 steps. It was demonstrated that these intermediates can be further vastly diversified into ANPs bearing both natural and unnatural nucleobases. Single enantiomers as well as racemates of final C1'-branched ANPs (overall 48 final compounds) were prepared and selected compounds were evaluated with respect to their biological properties. The aforementioned ANPs showed no antiviral potency against studied viruses and only weak to moderate cytostatic activity. Adenine C1'-branched ANPs proved to be the most potent currently known inhibitors of Trypanosoma brucei adenine phosphoribosyl transferase (TbrAPRT), an enzyme involved in purine salvage pathway (PSP) of T. brucei. Further biological evaluation of prepared compounds is in progress. Second part of this thesis was focused on development of novel prodrug moieties with higher selectivity index (i.e. toxicity/potency ratio - SI) based on so-called ProTide prodrugs where phenol (present in ProTides) was replaced by tyrosine derivatives. Tenofovir was...

This thesis deals with the preparation of acyclic nucleosides and nucleoside phosphonates of compounds T-705 (6-fluoro-3-hydroxypyrazine-2-carboxamide) and T-1105 (3-hydroxypyrazine-2-carboxamide). Acyclic nucleoside phosphonates are substances that can terminate viral RNA or DNA replication, and some of them are used in the treatment of viral diseases. T-705 and T-1105 have shown activity against the influenza virus, and T-705 has already been approved for its treatment in Japan. Since both compounds mimic natural nucleobases in the body, their acyclic nucleosides and nucleoside phosphonates also have the potential to be biologically active. Methods for the synthesis of 3-fluoro-2-(phosphonomethoxy)propyl and 3-hydroxy-2-(phosphonomethoxy)propyl derivatives of T-705 and T-1105, their prodrugs containing lipophilic groups for the improvement of the pharmacokinetic properties and also their phosphonate diphosphates, suitable for the biological activity measurements, have been proposed. Some of these derivatives were subsequently prepared. Key words: acyclic nucleosides, acyclic nucleoside phosphonates, T-705, T-1105, favipiravir, antiviral activity, influenza

PMEG [9-(2-phosphonomethoxyethyl)guanine] and PMEDAP [9-phosphonomethoxy- ethyl)-2,6-diaminopurine] are acyclic nucleoside phosphonates possessing cytotoxic properties. Antiproliferative effect of PMEG was demonstrated in various tumor cell lines in vitro. PMEG also represents an active component of some experimental prodrugs with enhanced selectivity and efficacy (such as GS-9219). PMEDAP seems to have weaker effect in vitro compared to PMEG, however it exhibited pronounced antitumor effect in SD-rats with spontaneous lymphoma. Therefore it was included in the present study as well. The aim of this study was to describe the interactions of PMEG and PMEDAP with p38 MAP kinase signaling and its relationship to the apoptosis. We investigated the influence of these compounds on the expression of four genes encoding p38 MAPK isoforms and whether this change is translated into the protein. It was found that PMEG up-regulates p38β and γ mRNA in CCRF-CEM cells and p38 β and δ in HL-60 cells. The effect of PMEDAP was less pronounced than that of PMEG. However, total p38 protein level remained unaffected by PMEG and PMEDAP. Activation of p38 MAPK cascade was also measured in the cells exposed to these agents using phospho-specific antibodies. We found that neither PMEG nor PMEDAP activated p38 kinase...

No description available.

The synthesis and properties of metal phosphonates prepared using piperazine-based bisphosphonic acids have been investigated. The ligands N,N’-piperazinebis(methylenephosphonic acid) (H₄L), and the 2-methyl (H₄L-Me) and 2,5-dimethyl (H₄L 2,5-diMe) derivatives have been prepared using a modified Mannich reaction. Hydrothermal reaction of gels prepared from metal (II) acetates and the bisphosphonic acids results in the synthesis of four structures: STA-12, Ni VSB-5, Co H₂L.H₂O and Mg H₂L. STA-12, synthesised by reaction of Mn, Fe, Co or Ni acetate with H₄L or H₄L-Me, has been investigated further. STA-12 crystallises in the space group R⁻₃, and Ni STA-12 is the most crystalline version. Its structure was solved from synchrotron data (a = b = 27.8342(1) Å, c = 6.2421(3) Å, α = β = 90°, γ = 120°), and it has large 10 Å hexagonal shaped pores. Helical chains of Ni octahedra are coordinated by the ligands, resulting in phosphonate tetrahedra pointing towards the pore space. Water is present, both coordinated to the Ni²⁺ cations and physically adsorbed in the pores. Mixed metal structures based on Ni STA-12, where some Ni is replaced in the gel by another divalent metal (Mg, Mn, Fe or Co) can also be synthesised. Dehydration of STA-12 results in two types of behaviour, depending on the metal present. Rhombohedral symmetry is retained on dehydration of Mn and Fe STA-12, the a cell parameter decreasing compared to the as-prepared structures by 2.42 Å and 1.64 Å respectively. Structure solution of dehydrated Mn STA-12 indicates changes in the torsion angles of the piperazine ring bring the inorganic chains closer together. Fe and Mn STA-12 do not adsorb N₂, which is thought to be due to the formation of an amorphous surface layer. Dehydration of Ni and Co STA-12 causes crystallographic distortion. Three phases were isolated for Ni STA-12: removal of physically adsorbed water results in retention of rhombohedral symmetry, while dehydration at 323 K removes some coordinated water forming a triclinic structure. A fully dehydrated structure (dehydrated at 423 K) was solved from synchrotron data (a = 6.03475(5) Å, b = 14.9156(2) Å, c = 16.1572(7) Å, α = 112.5721(7)°, β = 95.7025(11)°, γ = 96.4950(11)°). The dehydration mechanism, followed by UV-vis and Infra-red spectroscopy, involves removal of water from the Ni²⁺ cations and full coordination of two out of three of the phosphonate tetrahedra forming three crystallographically distinct Ni and P atoms. No structural distortion takes place on dehydration of Ni and Co STA-12 prepared using the methylated bisphosphonate, and the solids give a higher N₂ uptake as a result. Dehydrated Ni and Co STA-12 were tested for adsorption performance for fuel related gases and probe molecules. Investigations were undertaken at low temperature with H₂, CO and CO₂, and ambient temperature with CO₂, CH₄, CH₃CN, CH₃OH and large hydrocarbons. Due to the presence of lower crystallinity, Co STA-12 has an inferior adsorption performance to Ni STA-12, although it has similar adsorption enthalpies for CO₂ at ambient temperature (-30 to -35 kJ mol⁻¹). Ni STA-12 adsorbs similar amounts of CO₂ and N₂ at low temperature, indicating the adsorption mechanisms are similar. Also, it adsorbs 10 × more CO₂ than CH₄ at low pressure, meaning it could be used for separation applications. Ni STA-12 adsorbs 2 mmol g⁻¹ H₂ with an enthalpy of -7.5 kJ mol⁻¹, the uptake being due to adsorption on only one-third of the Ni²⁺ cations. The uptake for CO is 6 mmol g⁻¹, with adsorption enthalpies ranging from -24 to -14 kJ mol⁻¹. This uptake is due to adsorption on all the Ni²⁺, meaning the adsorption enthalpies are high enough to allow the structure to relax. This is also observed for adsorption of CH₃CN and CH₃OH, where there is a return to rhombohedral symmetry after uptake. The adsorption sites in dehydrated Ni and Co STA-12 were investigated via Infra-red spectroscopic analysis of adsorbed probe molecules (H₂, CO, CO₂, CH₃CN and CH₃OH). The results indicate the adsorption sites at both low and ambient temperature are the metal cations and the P=O groups. The metal cation sites are also characterised as Lewis acids with reasonable strength. STA-12 was shown to have acidic activity for the liquid phase selective oxidations of 1-hexene and cyclohexene, although there is evidence active sites are coordinated by products and/or solvents during the reaction. STA-12 also demonstrates basic activity for the Knoevenagel condensation of ethyl cyanoacetate and benzaldehyde. Modification of STA-12 by adsorption of diamine molecules causes a slight increase in the basicity, and the highest conversions are where water and diamine molecules are both present.

Les virus de l'Immunodéficience Humaine de type 1 et 2 (HIV-1 et HIV-2) et de l'Hépatite B (HBV) représentent un intérêt particulier en santé publique. En effet, on estime à plus de 33 millions le nombre de personnes infectées par le virus HIV dans le monde et 360 millions par HBV. La transcriptase inverse (RT) est une enzyme nécessaire à leur réplication et constitue donc une cible majeure des drogues antivirales. Parmi les NRTI commercialisés, les analogues de nucleotides de type phosphonates acyclique, comme l'Adefovir (HEPSERA®, Gilead) et le Tenofovir (VIREAD®, Gilead) sous forme prodrogue, ont révolutionné les traitements contre les virus HBV et HIV. Devant l'emmergence de virus résistants, il est urgent de développer de nouveaux antiviraux plus puissants et surtout actifs sur ces souches afin d'optimiser les multithérapies antivirales. Dans ce but, nous avons conçu des analogues thiophosphonates dérivés de l'Adefovir (PMEA) et du Tenofovir (PMPA), non toxiques pour la cellules et actifs contre HIV-1, HIV-2 et HBV en culture de cellules infectées. Ces composés, baptisés Adethiovir et Tenothiovir, ont été synthétisés selon une méthode originale et ont fait l'objet d'un dépôt de brevet. Nous avons synthétisé les formes diphosphates correspondantes : incorporés par la RT, terminateurs de chaîne, ils contournent la résistance associée au mutant K65R. Notre objectif est donc de les pousser plus loin dans le « pipe-line » du développement de médicaments antiviraux. / The Human Immunodeficiency Virus type 1 and type 2 (HIV-1 and HIV-2) and Hepatitis B (HBV) constitue a special interest in public health. Indeed, it is estimated that more than 33 million people infected with HIV worldwide and 360 million with HBV. Reverse transcriptase (RT) is an enzyme required for their replication and is therefore a key target for antiviral drugs. Among the NRTI marketed, nucleotide analogues like acyclic phosphonates, such as adefovir (Hepsera ®, Gilead) and Tenofovir (VIREAD ®, Gilead) as a prodrug form, have revolutionized the treatment against HBV and HIV. With the emmergence of resistant virus, there is a need to develop new antiviral compounds that are targetting especially these to optimize antiviral combination therapies. For this purpose, we designed analogues thiophosphonates derivatives Adefovir (PMEA) and tenofovir (PMPA), that are non-toxic in cells and active against HIV-1, HBV and HIV-2 infected cell cultures. These compounds, named Adethiovir Tenothiovir, were synthesized according to an original method and were the subject of a patent. We synthesized the corresponding diphosphates forms: incorporated by RT, chain terminators, they bypass the resistance associated with the K65R mutant. Our goal is to push them further in the "pipeline" development of antiviral drugs.

Im Rahmen dieser Dissertation wurden (I) erstmalig Metallphosphonate mechanochemisch synthetisiert, (II) 21 neue Strukturen mit Hilfe der Röntgenpulverdiffraktometrie gelöst und (III) die Reaktionsverläufe mittels in situ Methoden untersucht. Die Mechanochemie erwies sich als sehr geeignete Methode, um Metallphosphonate mit verschiedenen Metallen, Liganden und Strukturen darzustellen. Durch Variation des Verhältnisses der Edukte können die Reaktionen gesteuert werden. Etliche neue Metallphosphonat-Strukturen konnten mit Hilfe der erhaltenen Röntgenpulverdiffraktometrie-Daten gelöst werden. Dabei war auch die Aufklärung seltener Strukturmotive möglich. Durch die Resultate existiert nun eine schnelle, einfache und umweltfreundliche Alternative für die Herstellung von Metallphosphonaten. Im Rahmen dieser Arbeit wurden drei experimentelle Aufbauten für die in situ Untersuchung von Reaktionen entwickelt: (i) für mechanochemische Reaktionen mittels Synchrotron-Röntgenpulverdiffraktometrie und Raman-Spektroskopie, (ii) für mechanochemische Reaktionen mittels Thermographie und Raman-Spektroskopie sowie (iii) für Fällungsreaktionen bei Raumtemperatur mittels Synchrotron-Röntgenpulverdiffraktometrie. Durch die erhaltenen Ergebnisse konnten tiefgreifende Einblicke in die Bildungsmechanismen von Metallphosphonaten gewonnen werden. Für die mechanochemische Darstellung von Metallphenylphosphonaten wurde ein mehrstufiger Diffusionsmechanismus gefunden. Anhand der thermographischen Messungen wird deutlich, dass die Reaktionstemperatur einen großen Einfluss auf die Gesamttemperatur des Systems hat. Klassische Erklärungsmodelle für mechanochemische Reaktionen können für die hier untersuchten Systeme ausgeschlossen werden. Die in dieser Arbeit gewonnen Erkenntnisse über die Bildungsmechanismen und Strukturen der di- und tetravalenten Metallphosphonate liefern einen wichtigen Beitrag auf dem Weg zur zielgerichteten Darstellung von Metallphosphonaten. / In this dissertation (I) metal phosphonates were mechanochemically synthesized for the first time, (II) 21 new structures were solved from powder X-ray diffraction data and (III) the reaction pathways were investigated with in situ methods. Mechanochemistry has shown to be very suitable for synthesizing metal phosphonates with different metals, ligands, and structures. By varying the ratio of the reactants, it is possible to control the reaction pathway. Several new metal phosphonate structures were solved from the powder X-ray diffraction data. It was also possible to elucidate rare structures. The results demonstrate a new fast, facile, and environmental friendly alternative for the preparation of metal phosphonates. During this dissertation three experimental setups for the in situ investigation of reactions were developed: (i) for mechanochemical reactions via synchrotron-powder X-ray diffraction and Raman spectroscopy, (ii) for mechanochemical reactions via thermography and Raman spectroscopy and (iii) for precipitation reactions via synchrotron-powder X-ray diffraction. The gained results provided an insight into the formation of metal phosphonates. For the mechanochemical synthesis of metal phenylphosphonates a multi-step diffusion mechanism was found. From the thermography studies, it is proven that the reaction temperature has a big impact on the temperature of the whole system. Classical theories for mechanochemical reactions can be ruled out for the investigated systems. The results gained in this thesis about the formation mechanisms and structures of di- and tetravalent metal phosphonates provide an important contribution for the targeted synthesis of metal phosphonates.

Les systèmes hydrothermaux associés à la serpentinisation sont anoxiques et riches en $H_2$, $CH_4$ et molécules organiques. Ces composants alimentent des micro-organismes qui colonisent les systèmes serpentinisés, et ce en dépit d’un pH élevé et de faibles concentrations en accepteurs d'électrons et en carbone dissous. Dans ce travail, les communautés microbiennes ont été étudiées en se focalisant sur Prony, un écosystème serpentinisé côtier de Nouvelle-Calédonie, puis, en comparant différents écosystèmes serpentinisés, pour faire émerger des similarités taxonomiques et fonctionnelles. À Prony, nos analyses de métabarcoding ont mis en évidence l'importance d’une biosphère rare. L'analyse de métagénomes a permis de reconstruire 82 génomes procaryotes. Un de ces génomes est phylogénétiquement proche des espèces du genre Serpentinomonas, bactéries chimiolithotrophes isolées du site serpentinisé The Cedars, qui détiennent le record d’alcalophilie. Ces espèces et d'autres phylotypes, tels que les taxons affiliés aux Lost City Methanosarcinales, ont été trouvés dans plusieurs sites serpentinisés et pourraient contribuer à la définition d'une signature biologique des phénomènes de serpentinisation. En ciblant spécifiquement les métabolismes enrichis dans les milieux serpentinisés, nous avons pu mettre en évidence l'importance du métabolisme de l'hydrogène, des mécanismes cellulaires de réponse aux stress et d’une voie de dégradation des phosphonates, reposant sur l’activité d'une C-P lyase. Cette voie métabolique, qui a un rôle clé dans l'assimilation du phosphore et la libération de molécules organiques, vient enrichir les modèles écologiques des systèmes serpentinisés. / Serpentinizing hydrothermal systems are anoxic and enriched in $H_2$, $CH_4$ and organic molecules. These compounds support microbes that colonize serpentinizing systems, despite high pH and low concentrations of electron acceptors and dissolved inorganic carbon. In this work, two axes were explored to study the microbial communities. On the one hand, we focused on Prony, a coastal serpentinizing site in New Caledonia, and on the other hand we compared different serpentinizing systems to reveal taxonomic and functional similarities. At Prony, our metabarcoding analyses highlighted the importance of the rare biosphere. Moreover, 82 prokaryotic genomes were successfully reconstructed using five metagenomes from Prony. One of these genomes was phylogenetically close to the species of the genus Serpentinomonas, chemolithotrophic bacteria isolated at the serpentinizing site The Cedars that are capable of growth up to pH 12.5. These species, and other phylotypes, such as taxa affiliated with Lost City Methanosarcinales were identified in several serpentinizing sites and could contribute to the definition of a biological signature associated with serpentinization. By specifically targeting enriched metabolisms in serpentinizing environments, we highlighted key functions associated with hydrogen metabolism and environmental stress response mechanisms. The comparison of serpentinizing metagenomes revealed the importance of a phosphonate degradative pathway, based on the activity of a C-P lyase. This metabolic pathway, which plays a key role in the uptake of phosphorus and the release of organic molecules, was integrated into the ecological models of serpentinizing systems.