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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ring-opening polymerisation of 1,3-Dioxolan-4-ones

Cairns, Stefan Alexander January 2018 (has links)
Polyesters have been realised as a viable replacement for slow or non-degrading petroleum derived polymers. A variety of aliphatic polyesters, e.g. poly(lactic acid), have received a lot of attention because they are produced from renewable feedstocks and have the ability to biodegrade and bioassimilate. Poly(lactic acid)'s broader family, poly(α-hydroxy acid)s, have been produced with a wide variety of properties, that has given polyesters the potential for a more diverse range of applications. However, their synthesis has proven difficult. This thesis investigates a family of 1,3-dioxolan-4-ones as a monomer source to ease difficulties in current synthetic routes. Polymerisation of the parent 1,3-dixoxolan-4-one was tested. The copolymerisation of Llactide and 1,3-dioxolan-4-one was conducted with various monomer feedstocks. Ringopening polymerisation of 1,3-dioxolan-4-one led to the formation of paraformaldehyde as a polymerisation by-product. The copolymerisation was found to be best controlled when using a coordination-insertion type catalyst. 1,3-dioxolan-4-one was also copolymerised with ε-caprolactone and β-butyrolactone to produce copolymers with various compositions. The formation of poly(lactic acid) and poly(mandelic acid) from 5-methyl-1,3-dioxolan- 4-one and 5-phenyl-1,3-dioxolan-4-one was investigated. Poly(lactic acid) and poly(mandelic acid) were synthesised with either isotactic or atactic tacticities. Molecular weights were found to be lower than the expected values. A variety of MeAl(salen) catalysts were explored for the polymerisation of 5-methyl-1,3-dioxolan-4-one and catalysts ligated with tertiary-butyl substituted salens were found to have higher rates of polymerisation and reached high conversions. Altering the diimine bridge in the ligand led to variations in rates of polymerisation and molecular weights. The cause of the decrease in molecular weight was found to be caused by a side reaction. The side reaction was bypassed by polymerising 2,2,5- trimethyl-1,3-dioxolan-4-one and 2,2-dimethyl-5-phenyl-1,3-dioxolan-4-one to form poly(lactic acid) and poly(mandelic acid), respectively, with the expulsion of acetone. The scope of 1,3-dioxolan-4-ones capable of being polymerised to form poly(α-hydroxy acid)s was expanded to include iso-propyl, cyclohexyl, normal-butyl, iso-butyl, propargyl, chloromethyl and benzyloxymethyl substituents at the five position. The glass transition temperatures accessible from this synthetic route was expanded (22-105 °C). Kinetic experiments revealed the impact of the substituents steric bulk on the rate of polymerisation and points toward a coordination-insertion mechanism. Poly(lactic acid-co-glycolic acid) was copolymerised with 5-propargyl-1,3-dioxolan-4-one to incorporate alkynyl functionality and hence Raman spectroscopy showed the polymer had a distinct peak at 2128 cm-1. Following post-polymerisation modification of poly(lactic acid-co-3-chloro-2-hydroxypropanoic acid) copolymers, acrylate functionalised polymers were produced. The copolymers were shown to be capable of crosslinking poly(α-hydroxy acid) and poly(methyl methacrylate).
2

Les phosphates CDC25 constituent-elles des cibles importantes en cancérologie : Des inhibiteurs de l'activité enzymatique vers les inhibiteurs de l'interaction entre CDC25 et leurs substrats CDK-Cycline / Targeting CDC25 phosphatases : from inhibitors of the enzymatic activity towards inhibitors of the protein-protein interaction between CDC25 and CDK/Cyclin

Sarkis, Manal 28 November 2012 (has links)
Les phosphatases CDC25 sont des éléments-clé de la régulation du cycle cellulaire chez les eucaryotes; elles activent par une double déphosphorylation les complexes CDK/cyclines permettant ainsi la progression dans les différentes phases du cycle. Leur sur-expression, observée dans des cancers très fréquents, est corrélée à une forte agressivité des tumeurs et un mauvais pronostic ce qui en fait des cibles d’intérêt en cancérologie. Deux nouvelles séries d’inhibiteurs ont été développées à partir d’une thiazolopyrimidinone (TZP), capable d’inhiber l’activité des CDC25, et préalablement identifiée par l’équipe. La première série a été obtenue par dimérisation de deux noyaux thiazolones conduisant à des inhibiteurs avec des CI50 de l’ordre du micromolaire sur CDC25B plus actifs que les mono-thiazolones, ces composés étant sélectifs vs PTP1B et VHR. De plus, ces dimères semblent interagir avec le site actif et la poche de liaison des inhibiteurs. Une deuxième série d’analogues de thiazolidin-4-one a été obtenue par simplification de la structure TZP. Une réaction à quatre composants, utilisant l’énergie micro-onde, a été développée pour préparer rapidement des inhibiteurs de CDC25B avec des CI50 de l’ordre du micromolaire. Enfin, une approche originale pour inhiber CDC25 en ciblant l’interaction CDC25/CDK-Cycline a débutée. Un crible in silico/in vitro sera réalisé afin d’identifier de petites molécules inhibitrices de cette interaction. Des études préliminaires pour la mise en place d’outils permettant l’évaluation de l’affinité de ces molécules pour le site de reconnaissance de CDK2 ont été engagées. / CDC25 phosphatases are key regulators of the cell cycle and its checkpoints. Hence, they are required to dephosphorylate and thus activate the Cdk/Cyclin complexes triggering progression through the different phases. Over-expression of CDC25 has been demonstrated in a large number of human tumors and is often associated with aggressiveness and poor clinical prognosis. CDC25 phosphatases may therefore represent attractive targets for anti-cancer therapy. Starting from a thiazolopyrimidinone (TZP) structure, previously reported as CDC25 inhibitor in our laboratory, two series of new compounds have been developed. Dimerisation of the thiazolone scaffold led to bis-thiazolone derivatives with inhibitory activities in the micromolar range greater than that observed for the mono-thiazolones. Moreover, most of these compounds were selective CDC25 inhibitors. A second scaffold was designed by opening of the pyrimidine ring of the TZP, leading to thiazolidine-4-one derivatives that inhibit CDC25B activities with values of IC50 in the micromolar range. A four-component reaction, using micro-wave irradiation, was developed to rapidly prepare these compounds. Finally, an approach aiming at inhibiting the interactions between phosphatase CDC25 and its substrate CDK2 was engaged. Several virtual chemical libraries will be screened in silico, and the small molecules candidates selected will be assessed for their binding affinity using an in vitro assay, that we sought to develop.
3

3-amino-2-tiokso-tizolidin-4-ono darinių sintezė ir jų antimikrobinio poveikio įvertinimas / Synthesis of 3-amino-2-thioxo-thiazolidin-4-one derivatives and evaluation of antimicrobial activity

Smetanin, Vadim 18 June 2014 (has links)
Darbo tikslas: susintetinti 3-amino rodanino pagrindą turinčius junginius ir nustatyti jų antimikrobinį aktyvumą. Uždaviniai: 1) Sintezuoti 3-amiono-2-tiokso-4-tiazolidinono darinius; 2) Įvertinti gautų junginių antimikrobinį aktyvumą, naudojant in silico PASS online. 3) Įvertinti gautų junginių antimikrobinį aktyvumą in vitro standžioje terpėje; 4) Susieti junginių struktūrą su antimikrobiniu aktyvumu. Tyrimo metodai: sintetintų junginių antimikrobinis poveikis buvo prognozuojamas „PASS online“ programos pagalba. Antimikrobinis aktyvumas tirtas in vitro, naudojant Miulerio – Hintono agarą. Atlikti ESC tyrimai junginių grynumui nustatyti ir FT-IR tyrimai junginių struktūrai patvirtinti. Tyrimo rezultatai: 3-aminorodanino pagrindu buvo sintetinti 7 junginiai, turintys Šifo bazės struktūrą ir 1 turintis azetidino funkcinę grupę. Atlikti junginių lydymosi temperatūros nustatymo tyrimai, grynumas nustatytas naudojant ESC, junginių struktūra patvirtinta naudojant FTIR metodiką. PASS online programos pagalba buvo nustatyta, kad dauguma junginių turį potencialų antimikrobinį poveikį. Antimikrobinio poveikio in vitro tyrimo metu buvo nustatyta, kad plačiausią poveikį turi junginys VS-3, turintis p-chlorbenzaldehido pakaitą, ir VS-2, turintis p-brombenzaldehido pakaitą. Taip pat nustatyta, kad ribotu antimikrobiniu aktyvumu pasižymėjo junginiai VS-6, VS-7, VS-8. Įterpus azetidino struktūrą į VS-1 junginį, aktyvumas padidėjo Candida grybelių atžvilgiu. Išvados: iš sintetintų junginių... [toliau žr. visą tekstą] / The aim of the research: Synthesis of 3-aminorhodanine derivatives, antimicrobial evaluation. Methods: Antimicrobial activity of synthesized 3-aminorhodanine derivatives was predicted with the help of PASS online program. Factual antimicrobial activity of compounds was determined using in vitro agar method. The purity and structure of compounds was analyzed with ESC and FT-IR methods accordingly. Results: 7 Schiff base derivatives and one azetidine compound were synthesized on the base of 3-aminorhodonine. The melting points were identified, the purity of compounds were determined using ESC, the compound structure was identified using FTIR. Analyzing the compounds with PASS online showed that most of the compounds possess the potential of antimicrobial activity. In vitro antimicrobial studies showed that the widest spectrum of activity was possessed by compound VS-3, which had the 4-chlorbenzaldehyde moiety, and VS-2 with 4-bromobenzaldehyde moiety. Compounds VS-6, VS-7 and VS-8 showed limited antimicrobial activity. Modifying VS-1 structure by adding an azotidine moiety increased the drugs effect on Candida fungi family. Conclusion: amongst all the synthesized compounds 3-(4-chlorophenyl)methyleneamino]-2-thioxo-thiazolidin-4-one and 3-(4-bromphenyl)methyleneamino]-2-thioxo-thiazolidin-4-one showed most antimicrobial promise.
4

New functionalisation chemistry of 2- and 4-pyridones and related heterocycles

Fernandez, Beatriz January 2016 (has links)
New methodology for the synthesis of several 4H-pyrido[1,2-a]pyrimidin-4-ones has been developed from commercially available 2-aminopyridines and β-oxo esters catalysed by Montmorillonite under solvent-free conditions in good yields. This methodology was expanded for the synthesis of 4H-pyrimido[1,2-a]pyrimidin-4-one derivatives from 2-aminopyrimidine and different β-keto esters. The new methodology for the synthesis of N-alkylated 6-methyl 2-pyridones and N-alkylated 2-methyl 4-pyridones, from commercially available starting materials was developed. For the synthesis of N-alkylated 6-methyl 2-pyridones, 2-methoxy-6-methyl pyridine and a number of different alkylating reagents have been employed as starting materials. For the synthesis of N-alkylated 2-methyl 4-pyridones, 4-chloro 2-methyl pyridine was used successfully to make the desired pyridone in 3 steps. Selective mono-metallation at the 6-methyl substituent of N-alkylated 6-methyl 2-pyridones and N-alkylated 2-methyl 4-pyridones with n-BuLi/KHMDS at -78 °C proceeded smoothly, and the reactivity of the lithiated intermediates towards a wide range of electrophile (diketones, aldehydes, alkylating reagents) was studied. A straightforward synthesis of desirable 4H-quinolizin-4-one scaffolds by condensation of N-benzyl 6-methyl 2-pyridones with dicarbonyl compounds, and the formation of the desired quinolizinone after the condensation step was achieved. An unexpected quinolizinone bearing a fused β-lactam ring was isolated and its structure confirmed by single crystal X-ray diffraction analysis.
5

Metabolism & Signaling of 4-Hydroxyacids: Novel Metabolic Pathways and Insight into the Signaling of Lipid Peroxidation Products

Sadhukhan, Sushabhan 27 August 2012 (has links)
No description available.
6

Estudos químicos e biológicos de compostos heterocíclicos derivados dos núcleos imidazolidina-2,4-diona e 2-tioxoimidazolidina-4-ona

Souza, Severino Araújo de 06 April 2015 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-06-27T14:51:56Z No. of bitstreams: 1 arquivototal.pdf: 8326748 bytes, checksum: beabc8048bb16f0e1b36cca198214348 (MD5) / Made available in DSpace on 2017-06-27T14:51:56Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 8326748 bytes, checksum: beabc8048bb16f0e1b36cca198214348 (MD5) Previous issue date: 2015-04-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The breakthrough occurred in the scientific world involving chemical and pharmacological studies of heterocyclic are the result of the large investment from pharmaceutical companies and research centers in universities. Synthetic Heterocyclic compounds stand out because of the possibilities these compounds present several different biological properties. Structural changes in imidazolidínico and tioimidazolidínico rings can change their chemical, physical properties and produce biological effects with a variety of useful applications. The objective of this work was the synthesis and characterization of heterocyclic compounds of imidazolidine-2,4-dione class and 2-thioxo-imidazolidine-4-one in order to investigate their pharmacological potential as antimicrobial, antinociceptive, anti-tumor and anticonvulsant and study their thermal stability. The compounds were obtained in two steps: first, reacted sodium cyanide, ammonium chloride, methylammonium chloride, isopropylammonium chloride and substituted aromatic aldehydes to, followed by acid hydrolysis to form the amino acid derivatives of glycine. In the second stage, there was the reaction of amino acids prepared with potassium isocyanate and ammonium isothiocyanate and / or phenyl isocyanate and / or phenyl isothiocyanate followed by acid hydrolysis to form the imidazolidínicos derivatives: IM-15; HPA-05; HPA-09; HPA-10; HPA-14; HPA-15A; HPA-15B; HPA-15C; HPA-15D; HPA-15E; HPA-15F; HPA-15G; HPA-15H; HPA-15J and tioimidazolidínicos: HPA-03; HPA-04; HPA-08; HPA-11; HPA-15I; HPA-15M. The structures of the synthesized compounds were characterized by IR absorption spectroscopy, 1H-NMR and 13C-NMR. With the synthesized compounds investigated the potential front Antimicrobial studies, antinociceptive, anticarcinogenic and CNS. Also evaluated the thermal stability of the synthesized compounds and in silico studies. / O grande avanço ocorrido no mundo científico envolvendo os estudos químicos e farmacológicos de heterocíclicos são frutos do grande investimento das indústrias farmacêuticas e dos centros de pesquisas nas universidades. Os compostos heterocíclicos sintéticos se destacam devido às possibilidades existentes nesses compostos de apresentar várias propriedades biológicas diferentes. Modificações estruturais nos anéis imidazolidínico e tioimidazolidínico podem alterar suas propriedades químicas, físicas e produzir efeitos biológicos com uma grande variedade de aplicações úteis. O objetivo desse trabalho foi a síntese e caracterização de compostos heterocíclicos da classe imidazolidina-2,4-diona e 2-tioxo-imidazolidina-4-ona com a finalidade de investigar suas potencialidades farmacológicas como antimicrobianos, antinociceptivos, antitumoral e anticonvulsivante e estudar sua estabilidade térmica. Os compostos foram obtidos em duas etapas: na primeira, fez-se reagir cianeto de sódio, cloreto de amônio, cloreto de metilamônio, cloreto de isopropilamônio e aldeídos aromáticos para substituídos, seguido de hidrólise ácida para a formação dos aminoácidos derivados da glicina. Na segunda etapa, fez-se a reação dos aminoácidos preparados com isocianato de potássio e isotiocianato de amônio e/ou fenilisocianato e/ou fenilisotiocianato seguido de hidrólise ácida formando os derivados imidazolidínicos: IM-15; HPA-05; HPA-09; HPA-10; HPA-14; HPA-15A; HPA-15B; HPA-15C; HPA-15D; HPA-15E; HPA-15F; HPA-15G; HPA-15H; HPA-15J e tioimidazolidínicos: HPA-03; HPA-04; HPA-08; HPA-11; HPA-15I; HPA-15M. As estruturas dos compostos sintetizados foram caracterizadas através da espectroscopia de absorção no IV, de RMN de 1H e RMN de 13C. Com os compostos sintetizados investigou a potencialidade frente aos estudos Antimicrobianos, Antinociceptivos, Anticarcinogênico e sobre o SNC. Avaliou também a estabilidade térmica dos compostos sintetizados e os estudos in silico.
7

Développement de nouvelles méthodes de synthèse en chimie de fluor et préparation de molécules bioactives / Development of new methods of synthesis in fluorine chemistry and preparation of bioactive molecules

Nasr El Dine, Assaad 08 December 2015 (has links)
Ce travail s'inscrit dans le cadre d'un programme de collaboration entre l'Université Libanaise et l'université de Rennes 1. La thèse est divisée en deux parties :Chimie du fluor : synthèse de nouveaux hétérocycles portant des chaînes latérales fluorées ; chimie médicinale : recherche de nouvelles molécules à visées anticancéreuses. La première partie se compose de trois chapitres : dans le premier chapitre, des intermédiaires de synthèse de type énones fluorées ont été synthétisés par une voie originale, et leur réactivité en cyclocondensation a été étudiée pour obtenir de pyrazolines et de pyrrolines avec des chaînes latérales fluorés. Dans le deuxième chapitre, nous nous sommes intéressés à la préparation d'hétérocycles de type chroman-4-one, en utilisant les intermédiaires difluorés précédents. Dans le dernier chapitre, la réaction de Kinugasa a été appliquée pour la première fois sur des dérivés propargyliques gem-difluorés. Cette réaction nous a permis de découvrir une voie de synthèse originale à une famille de composés nouveaux, à savoir des exoalkylidène b-lactames portant un fluor en position vinylique. Dans la seconde partie, notre objectif était de restaurer les propriétés apoptotiques au sein des cellules cancéreuses afin d'obtenir de nouveaux composés à activité antitumorale. A partir de données obtenues par modélisation moléculaire, nous avons fait le design de plusieurs séries d'analogues d'un inhibiteur connu (MIM-1) de la protéine anti-apoptotique Mcl-1. Plus de 40 analogues ont été préparés et testés sur trois variétés de cellules cancéreuses (sein, ovaire et mélanome). Un certain nombre de ces composés ont présenté des activités prometteuses dans ces différents domaines. / This work is a part of a collaboration program between Lebanese University and University of Rennes 1. The thesis is divided into two parts: fluorine chemistryv : synthesis of new heterocycles bearing fluorine-containing side chains ; medicinal chemistry : research towards new anticancer molecules. The first part consists of three chapters: in the first chapter, gem-difluoro enone-type intermediates were synthesized through a new route and their cyclocondensation reactions were studied to get pyrazolines and pyrrolines with fluorinated side chains. In the second chapter, type-chroman-4-one heterocycles were prepared using the previous difluorinated intermediates. In the third chapter, the Kinugasa reaction was applied for the first time on gem-difluoro propargylic derivatives. This reaction has allowed us to discover a pathway to a new family of molecules, the fluorine-containing exoalkylidene β-lactames. In the second part, our goal was to reinduce the proapoptotic properties in cancer cells in order to obtain new antitumor compounds. Starting from data obtained through molecular modeling studies, we designed and prepared several series of analogs for a known inhibitor (MIM-1) of the anti-apoptotic protein Mcl-1. Over 40 analogs have been synthetized and screened towards three types of cancer cells (breast, ovarian and melanoma). Some of these derivatives have demonstrated promising data in these areas.
8

Préparation et dérivatisation de 4H-pyrido[e][1,3]oxazinones : une contribution à la diversité chimique / Preparation and derivatization of 4H-pyrido[e][1,3]oxazinones : a contribution to chemical diversity

Le Falher, Laetitia 07 November 2014 (has links)
Ce manuscrit porte sur la synthèse et les applications d'une nouvelle série de composés hétéroaromatiques : les 4H-pyrido[e][1,3]oxazin-4-ones. La première partie de ce manuscrit présente la préparation de ces squelettes via une réaction d'O-arylation intramoléculaire. La seconde partie du manuscrit repose sur la réactivité de ces entités chimiques et de leur utilisation en tant qu'intermédiaires de synthèse. La fonctionnalisation des 4H-pyrido[e][1,3]oxazin-4-ones, via des réactions de couplage pallado-catalysées, a permis d'obtenir des systèmes polyfonctionnalisés plus complexes. Les pyrido-oxazinones ont également été transformées, en une étape, en divers petits hétérocycles d'intérêt : les 1,3,5-triazines, les 1,2,4-triazoles et les 1,2,4-oxadiazoles. La dernière partie du manuscrit est consacrée à l'utilisation des molécules synthétisées comme potentielles sondes fluorescentes pour la détection de protéines oxydées. / This work focused on the synthesis and applications of a novel series of heteroaromaticcompounds: the 4H-pyrido[e][1,3]oxazin-4-ones. The first part of this thesis presents thepreparation of these pyrido-oxazinones via an intramolecular O-arylation reaction. The secondpart of this work relies on the reactivity of these chemical entities and their use as buildingblocks. The functionalization of the 4H-pyrido[e][1,3]oxazin-4-ones has been studied viacross-coupling reactions to obtain more elaborated structures. The pyrido-oxazinones werealso converted, in one step, into other diverse small molecules of interest: 1,3,5-triazines,1,2,4-triazoles and 1,2,4-oxadiazoles. The last part of this thesis was devoted to the use of theobtained heterocycles as potential fluorescent probes for the detection of carbonylatedproteins.

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