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1
Zhang, Xinfeng. "Nonenzymatic formation of advanced glycation endproducts by glucosamine autocondensation and glucosamine with proteins /". View online ; access limited to URI, 2003. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3112135.
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Fox, Beth Anne, Evan D. Schmitz y Rick L. Wallace. "Glucosamine and Chondroitin for Osteoarthritis". Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/8684.
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3
Bazito, Reinaldo Camino. "Novos tensoativos derivados da 2-D-glucosamina". Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-12092006-143935/.
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Foram sintetizadas duas novas séries de tensoativos de açúcar derivados da 2-D-glucosamina: os metil 2-acilamido-2-deóxi-6-O-sulfonato-D-glucopiranosídeos de sódio (aniônicos) e os cloretos de metil 2-acilamido-2,6-dideóxi-6-trimetilamônio-D-glucopiranosídeos (catiônicos). Os tensoativos aniônicos foram obtidos pela acilação da 2-D-glucosamina com cloretos de acila (com 8, 12 e 16 carbonos), seguida pela metilação desses derivados com metanol em meio ácido, e posterior sulfatação dos metil glucosídeos com complexo trióxido de enxofre-piridina. Os tensoativos catiônicos foram obtidos pela tosilação dos metil glucosídeos, seguida pela quaternização com trimetilamina e troca do contra-íon tosilato por cloreto com resina de troca-iônica. Esses tensoativos apresentaram c.m.c. similares a de outros tensoativos iônicos de cadeia hidrofóbica de igual comprimento, mas energias livres de transferência do grupo polar para a micela muito mais favoráveis. Esse fato foi atribuído à formação de ligações de hidrogênio entre os grupos polares do tensoativo na micela, e à hidrofobicidade do açúcar. As micelas formadas apresentaram números de agregação maiores que os obtidos para outros tensoativos, provavelmente devido às interações atrativas entre os grupos polares.Two new sugar-based surfactant series were synthesized from 2-D-glucosamine: sodium methyl 2-acylamido-2-deoxi-6-O-sulfonate-D-glucopyranosides (anionic) and methyl 2-acylamido-2,6-dideoxi-6-trimethylamonium-D-glucopyranoside chlorides (cationic). The anionic surfactants were obtained by the acylation of 2-D-glucosamine with acyl chlorides (with 8, 12 and 16 carbons), followed by the methylation of these derivatives with methanol in acidic media, and the sulfation of the methyl glucosides with sulfur trioxide-pyridine complex. The cationic surfactants were obtained by the tosylation of methyl glucosides followed by the quaternization with trimethylamine and exchange of the tosylate contra-ion with chloride ions on an ion exchange resin. These surfactants showed c.m.c. similar to other ionic surfactants with equal hydrophobic chain lengths, but more favorable free energies of transfer of the polar head to the micelle. This fact is attributed to hydrogen bonding between the head groups of the surfactant in the micelle, and the hydrophobicity of the sugar moiety. The micelles of these surfactants showed aggregation numbers larger than those obtained for other surfactants, problably because of head-group attractive interactions.
4
Gentil, Emmanuel. "Utilisation de dérivés 2-alkoxycarbonyles du d-glucose et de la d-glucosamine en synthèse glycosidique". Lyon 1, 1990. http://www.theses.fr/1990LYO10229.
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Ce travail a permis d'estimer l'influence de la nature d'un groupe participant alkoxycarbonyle en synthese glycosidique a partir du d-glucose et de la d-glucosamine. Dans une premiere partie, les donnees de la litterature concernant le role et l'importance des orthoesters dans les reactions de glycosylations de type koenigs-knorr ainsi que l'utilisation de derives 2-o-alkoxycarbonyles du d-glucose en synthese glucosidique ont ete analysees. La synthese stereoselective, l'analyse structurale et les rearrangements acido-catalyses d'1,2-orthocarbonates ont ensuite ete exposes. Cette etude a permis une interpretation mecanistique des reactions de glycosylation des derives 2-o-alkoxycarbonyles du d-glucose qui differe de celle avancee pour les analogues esterifies. Le mecanisme reactionnel suppose un intermediaire de type alkoxydioxocarbenium dont la participation, suivie de l'attaque de l'alcool, conduit aux -d-glucosides et aux orthocarbonates par deux chemins reactionnels independants. Dans une deuxieme partie, apres commentaires des donnees bibliographiques concernant les methodes de glycosylations appliquees a la synthese de (1-4) glycosides derives de la d-glucosamine, des accepteurs de glycosyle n-allyloxycarbonyles derives de la d-glucosamine, ont ete synthetises par diverses voies. Lors des reactions de glycosylations avec les donneurs 2-n-allyloxycarbonyles derives de la d-glucosamine, ces accepteurs se sont montres tres peu reactifs. Cette faible reactivite inattendue pourrait etre la consequence d'un effet particulier du groupement protecteur 2-allyloxycarbonylamine des accepteurs
5
Brown, Martin F. "Glucosamine synthetase inhibitors : synthesis, kinetics and antibacterial properties". Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317549.
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Munoz, Nicole. "Glucosamine reduces glycogen storage in L6 skeletal muscle cells". Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/n_munoz_112507.pdf.
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Marie, Corinne. "Roles of two Rhizobium leguminosarum glucosamine synthases in symbiosis". Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334333.
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8
Blackwell, Amy Marie. "GLUCOSAMINE AND INSULIN RESISTANCE: A SYNTHESIS OF CURRENT RESEARCH". Thesis, The University of Arizona, 2003. http://hdl.handle.net/10150/609992.
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In the early 1980's, Glucosamine Sulfate was
introduced as a non -FDA approved, herbal supplement for the
treatment of oteoarthritis (Adams, 1999).Preliminary
evidence shows that long -term use of Glucosamine can slow
joint space narrowing caused by osteoarthritis (Adams).
Animal studies were conducted to assess the
effectiveness and mechanisms of action of glucosamine.
Glucosamine's insulin resistant property was discovered
during the animal studies. The purpose of this project was
to conduct a review of the literature to determine if there
was enough human anecdotal and /or rat empirical data to
warrant further study in humans on the impact of
glucosamine on insulin resistance.
Data gathered in this project provided evidence that
glucosamine leads to insulin resistance in animals.
Awareness of the insulin resistant properties of
glucosamine noted in animal studies, coupled with the lack
of well -controlled studies of effect and impact on humans,
demonstrates the need to continue study in humans to
determine the effect of glucosamine on insulin resistance
in humans.
9
Renaud, Anne-Laure. "Réactions stéréosélectives basées sur des dérivés de la glucosamine". Université Louis Pasteur (Strasbourg) (1971-2008), 2001. http://www.theses.fr/2001STR13199.
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Ce travail s'inscrit dans le cadre de la recherche de nouveaux auxiliaires chiraux basés sur des sucres, dont les modes d'action seraient basés sur des interactions non covalentes. Des dérivés de la glucosamine portant à la fois une insaturation (double liaison allylique ou énolate) et un groupe aromatique ont été préparés. Une interaction de type p ou une liaison hydrogène entre ces deux éléments liés au sucre devait permettre de bloquer une des faces diastéréotopiques de l'insaturation et n'autoriser l'accès du réactif que sur une seule face. Dans la première approche, des allylglucosamines portant différents groupes N-protecteurs ont été préparées et soumises à des réactions d'époxydation avec différents oxydants. La stéréosélectivité de ces réactions variait de 4 à 72% d'excès diastéréomérique. Les méthodes mises au point ont été appliquées à la synthèse d'un inhibiteur potentiel de glycosidases. Dans une deuxième approche, des N-acylglycosamines portant un groupe aromatique en position anomérique ont été synthétisées puis aldolisées en milieu basique. La sélectivité de ces réactions a parfois atteint 40%, mais l'origine de cette sélectivité n'a pas pu être totalement rationalisée. L'ensemble de ces résultats a permis de mettre au point différentes méthodes de synthèse applicables à la chimie très particulière de la glucosamineThis work concerns the search for new chiral auxiliaries based on carbohydrates, using non-covalent interactions. Glucosamine derivatives bearing an insaturation (allylic double bond or enolate) and an aromatic group have been prepared. A p-interaction or a hydrogen bond between these two pendant groups had to be able to block one diastereotopic face of the insaturation. In a first approach, allylglucosamines bearing various N-protecting groups were prepared and epoxidized. The stereoselectivity of these reaction varied from 4 to 72% diastereomeric excess. The methods developped have been applied to the synthesis of a potential glycosidase inhibitor. In a second approach, N-acylglucosamines bearing an aromatic group at the anomeric position were synthesized and submitted to aldol reactions. The selectivity of these reactions reached 40% in some cases, but the origin of this selectivity could not be fully explained
10
Dutta, Udayan. "Advanced glycation endproducts analysis of glucosamine with reducing sugars, DNA nucleosides and serum proteins /". View online ; access limited to URI, 2005. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3188840.
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Sancho, Marie-Rose. "Synthèse de ß-glycosides amphiphiles de la D-glucosamine : étude de leur incorporation dans de petits liposomes unilamellaires". Lyon 1, 1994. http://www.theses.fr/1994LYO10260.
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Depuis de nombreuses annees, les liposomes suscitent un grand interet en tant que transporteurs de substances actives. La presence a la peripherie des vesicules, de ligands pouvant etre reconnus par des recepteurs situes a la surface de cellules cibles, devrait permettre un meilleur pilotage des liposomes in vivo. Dans ce contexte, cette etude concerne la preparation de liposomes recouverts de groupements saccharidiques, par insertion de glycosides amphiphiles dans les bicouches phospholipidiques. Apres un premier chapitre bibliographique consacre a la preparation et aux applications de liposomes a couverture saccharidique externe, un second chapitre expose la synthese de divers glycosides amphiphiles de la beta-d-glucosamine. Des composes monocatenaires ont ete prepares a partir d'alcools gras lineaires de longueur variee. Des derives bicatenaires ont ete synthetises a partir de 1,3-diethers du glycerol, relies a la glucosamine par un bras espaceur hydrophile (de type polyethyleneglycol). Un glycoside a egalement ete prepare a partir du cholesterol. Le troisieme chapitre decrit l'incorporation des differents amphiphiles dans des petits liposomes unilamellaires. Cette etude a ete realisee grace a des techniques de double marquage radioactif (#1#4c et #3h). L'influence de la nature de l'ancre hydrophobe a ete demontree. Les meilleurs taux d'incorporation ont ete obtenus pour les glycosides bicatenaires et pour celui du cholesterol. L'incorporation des glycosides monocatenaires depend de la longueur de leur chaine alkyle. La taille des liposomes prepares avec et sans glycoside a ete determinee par diffusion quasi elastique de la lumiere. Une etude de la variation du diametre des vesicules en fonction du temps a montre l'influence de la nature du glycoside sur la stabilite des liposomes. Le glycoside du cholesterol donne les resultats les plus interessants. La possibilite de former des vesicules closes a partir des glycosides bicatenaires seuls a egalement ete mise en evidence
12
Appourchaux, Philippe. "Etude des endo-N-acétyl-bêta-D-glucosaminidases cytosoliques du foie de rat : purification, propriétés physico-chimiques et enzymatiques". Lille 1, 1987. http://www.theses.fr/1987LIL10161.
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Wieczorek, Florence. "Les oximes dans la recherche d'inhibiteurs de la glucosamine-6P Synthase : Synthèses, études physico-chimiques et évaluations in vitro". Paris 11, 2010. http://www.theses.fr/2010PA112092.
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La Glucosamine-6P synthase (GlmS) catalyse l’étape limitante de la biosynthèse des hexosamines. Sa surexpression est à l'origine des complications liées au diabète et son inhibition constitue donc une nouvelle piste thérapeutique. Au cours de ce travail, nous avons développé des outils pour la conception de nouveaux inhibiteurs de la GlmS selon une stratégie par assemblage de fragments. Une synthèse en parallèle d'O-aryloxyamines et d'éthers d'oxime de sucres phosphates a d’abord été mise au point. Un test permettant l’analyse simultanée par spectrométrie de masse des deux activités de l’enzyme (glutaminase et synthase) a ensuite été développé. La stéréospécificité de l’interaction des deux stéréoisomères des éthers d’oxime avec la protéine a enfin été étudiée par RMN en utilisant la technique de transfert de saturation (STD), ce qui a permis de mettre en évidence l’existence de deux sites de fixation distincts, spécifiques de chacun des isomèresThe hexosamine biosynthetic pathway is closely associated with the side effects of diabetes. The conversion of fructose-6P (Fru6P) into glucosamine-6P (GlcN6P), the rate-limiting step in this pathway, is catalyzed by glucosamine-6P synthase (GlmS). This enzyme is hence considered as a potential therapeutic target for the treatment of vascular complications linked to diabetes. During this project, we set up the necessary tools for the discovery of new specific GlmS inhibitors using a fragment-based strategy. Therefore, O-aryloxyamines and oxime ethers were prepared using parallel synthesis. A mass spectrometry assay allowing simultaneous analysis of glutaminase and synthase enzyme activities was developed. Finally, the study of the interaction between GlmS and oxime ether isomers by Saturation Transfer Difference NMR revealed for the first time the existence of two separate binding sites specific of each isomer
14
Li, Tsz-shan y 李芷珊. "Systematic review of the effectiveness of glucosamine for knee osteoarthritis". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48424250.
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Objective: To investigate the effectiveness of glucosamine for knee osteoarthritis (KOA) through the examination of symptomatic and structural effectiveness of the compound, and to increase public awareness, especially in Hong Kong, about its potential benefits contingent upon the quality of the existing research.
Methods, Results: All studies published between 1965 and 2011 in MEDLINE, and from 1980 to 2012 in EMBASE, which evaluated the effectiveness of glucosamine for KOA, were searched and identified using specific keywords. A total of 9 randomized controlled trials out of 672 articles from MEDLINE and 1712 articles from EMBASE were included in this systematic review. The included studies used different outcome measures to compare the effects of glucosamine with other remedies for treating KOA. Similar demographic and clinical characteristics of the subjects between the intervention and the control groups were recorded. The studies were from eight countries. The average age of the subjects in the nine studies were 55 years and they were generally overweight. Though there were discrepancies among the results generated in the included studies, the potential benefits of glucosamine could not be dismissed.
Discussion: Factors about compliance, possible drug-to-drug interaction, unknown placebo, subject characteristics (disease progress and severity, age, gender, and occupation), as well as the dosage of glucosamine could have greatly affected the results of the included studies. Limitations on finding articles about the effectiveness of glucosamine for OA of different sites, the cost-effectiveness of the compound, the assumption of the language restriction, and the risks of biases were raised. More clinical trials with comprehensive considerations of all possible factors affecting the results, are necessary.
Conclusion: Based on this systematic review, the potential effects of glucosamine for KOA remain unclear. More research of different ethnic groups, especially of people in Hong Kong, is needed to raise public awareness about the effectiveness of glucosamine for OA other than the knee globally as well as in Hong Kong.published_or_final_version
Public Health
Master
Master of Public Health
15
Scoponi, Giulia. "Lewis acid catalysed direct glycosylation of N-acetyl-D-glucosamine". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14450/.
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Incorporation of the relevant monosaccharide N-Acetyl-D-glucosamine (GlcNAc) into synthetic oligosaccharides by chemical glycosylation is still a very challenging object of studies, since direct reactions are low yielding. This issue is generally ascribed to its low solubility in common solvents and to the formation of a poorly reactive oxazoline intermediate, which is typically bypassed by introducing extra synthetic steps to avoid the presence of the NHAc moiety during glycosylation. Recently, a new direct Lewis acids-catalysed GlcNAc-ylation protocol has been disclosed, with acylated donors appearing to hold potential for high yielding glycosylation reactions. This master project focused indeed on a novel synthesis of promising 1-acyl GlcNAc donors, in order to test them in direct Lewis acid catalysed glycosylation without the need of N-protecting groups. Screening of various Lewis acids and reaction conditions with these acylated donors has been carried out, in presence of reactive primary alcohols as well as more challenging carbohydrate acceptor alcohols. These experiments demonstrated that the fine tuning of the leaving group combined with a suitable metal triflate could lead to a successful reaction outcome in the direct glycosylation.
Successful methodology of this kind would provide rapid access to naturally occurring N-glycan motifs, such as the highly relevant human milk oligosaccharides (HMOs).
16
Cheuk, Sherwin. "Glucose and Glucosamine Derivatives as Novel Low Molecular Weight Gelators". ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/868.
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Low molecular weight gelators (LMWGs) are small molecules that are capable of entrapping solvents to form a gel in organic solvents or aqueous solution. These compounds rely solely on noncovalent forces to form the fibrous networks necessary to entrap a variety of solvents. The organogels and hydrogels thus formed could have applications in a variety of fields from environmental to biological to medicinal. Carbohydrates are ideal starting materials to synthesize LMWGs, because of their natural abundance, dense chirality, and biocompatibility. D-Glucose is the most common monosaccharide and D-glucosamine is isolated from natural sources, such as crab shells. Several series of compounds were synthesized using compounds 1-3 as the starting materials. These include esters, carbamates, amides, and ureas. The structure and gelation relationship was analyzed to obtain guidelines for designing new LMWGs. Compound 1 is a simple derivative of D-glucose and its terminal alkynyl esters and saturated carbamates are effective gelators. Compound 2 is a simple derivative of D-glucosamine and its amide and urea derivatives are also effective gelators. Compound 3 is formed from the deoxygenation of D-glucose. 1OOHOOCH3OHOPh2OOHOOCH3NH2OPh3OOHOOHOPh The design, synthesis and gelation properties of several classes of sugar based low molecular organo/hydrogelators will be discussed in this thesis in chapters 2, 3, and 4. After obtaining highly effective organo/hydrogelators, potential applications of these novel molecular systems can be explored. Some preliminary study on using one of the gelator in enzyme assay has shown that it is possible to utilize the hydrogels to immobilize enzymes. However, future research can explore further on the applications of these gelators.
17
Sengmany, Stéphane. "Synthèse et évaluation d'analogues d'hexoses-phosphates, intermédiaires de la réaction catalysée par la glucosamine-6-phosphate synthase : étude in silico des complexes enzyme-inhibiteur". Paris 11, 2003. http://www.theses.fr/2003PA112005.
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Dans le cadre de l'étude du mécanisme d'action de la Glucosamine-6-phosphate Synthase (GlmS), enzyme-clé de la voie de biosynthèse des hexosamines, des analogues de l'intermédiaire cis-énolamine ont été synthétisés; il s'agit de dérivés hydroxamate et amidoxime. Le remplacement du groupe phosphate nécessaire à l'activité par des groupes isostères plus stables tels que le méthylène- et le difluorométhylènephosphonates, a également été effectué. Les phosphates de l'arabinohydroxamate et de l'arabinoamidoxime sont obtenus respectivement en deux étapes à partir du glucose-6-phosphate, et en dix étapes à partir du D-arabinose. Les dérivés phosphonates sont préparés à partir du D-glucose en dix étapes. Ces composés, évalués sur l'activité de la GlmS, présentent une inhibition compétitive vis-àvis du fructose-6-phosphate. L'arabinohydroxamate phosphate, bien que présentant une excellente inhibition sur la Phosphoglucose Isomérase (Ki = 1 mM), n'est que faiblement inhibiteur de la GImS (Ki = 900 mM). Ses analogues méthylène- et difluorométhylène phosphonates sont encore moins bons avec des Ki respectifs de 1600 mM et 8500 mM. En revanche, l'arabinoamidoxime phosphate est un bon inhibiteur de la GImS avec un Ki de 65 mM. Une tentative de rationalisation des résultats des tests d'inhibition a été réalisée en utilisant les expériences de "docking" moléculaire de ces composés dans le site actif de la GImSIn the present mechanistic study of Glucosamine-6-phosphate Synthase (GImS), a key enzyme in the biosynthesis pathway of hexosamines, new analogues of the cis-enolamine intermediate, namely hydroxamate and amidoxime compounds, were synthesized. The replacement of the phosphate group necessary to the activity by more stable isostere groups such as methylene- and difluoromethylenephosphonates was also studied. Phosphate derivatives of arabinohydroxamate and arabinoamidoxime were respectively obtained in two steps starting from glucose-6-phosphate, and in ten steps starting from D-arabinose. Phosphonate analogues were prepared in ten steps starting from D-glucose. These compounds, evaluated as inhibitors on the activity of GlmS, present a competitive inhibition versus fructose-6-phosphate. While the arabinohydroxamate phosphate was revealed as an excellent inhibitor of Phosphoglucose Isomerase (Ki = 1 mM), its inhibition efficiency on GlmS is moderate (Ki = 900 mM). Its methylene- and difluoromethylenephosphonate analogues are even worse with respective Ki of 1600 and 8500 mM. On the other hand, the arabinoamidoxime phosphate is a good inhibitor of GlmS with Ki of 65 mM. An attempt to rationalize the results of inhibition assays was carried out by using molecular docking experiences of these compounds in the GlmS active site
18
Parikh, Bhargiv. "Design, Synthesis and Characterization of D-glucosamine Low Molecular Weight Gelators". ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1110.
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Low molecular weight gelators (LMWGs) have gained much attention over the last few decades, because of their ability to form supramolecular architectures as well as their many potential applications in biomedical research and as advanced materials. Most of the gelators were discovered through serendipity, and their structural requirements are somewhat ambiguous. This is due, in part, to the fact that the supramolecular gelation phenomenon is not yet fully understood, though many structural classes have been found to be excellent organogelators. Carbohydrates are abundant natural resources that are useful in preparing advanced materials. We have previously showed that monosaccharide derivatives can form effective low molecular weight gelators for both organic solvents and aqueous mixtures. In this research, we have studied the gelation capability of several glucosamine derivatives. Several series of 4,6-O-acetal protected glucosamine derivatives were synthesized and screened for their gelation properties in several solvents.
19
Moukarzel, Waêl. "Synthèse et caractérisation de glycosilicones et leur application à la préparation et stabilisation de nanoparticules d'or". Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1628/.
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Le couplage d'une chaîne siloxane avec des groupements fonctionnels divers donne accès à des polymères aux propriétés originales couplant la flexibilité de la chaîne avec les propriétés des groupes fonctionnels. Dans cet état d'esprit, nous avons souhaité étudier le couplage de groupements de type saccharidiques aux chaînes de polysiloxane. Dans une première partie de ces travaux de thèse, une nouvelle méthode rapide, douce et efficace a été mise au point pour la préparation de polysiloxanes linéaires ou hyperbranchés à groupements saccharidiques, en position latérale ou terminale. La préparation se fait sans utilisation de groupements protecteurs de sucres, permettant ainsi d'éviter les conditions usuelles acides ou basiques de déprotection et de conserver ainsi l'intégralité des chaînes siloxanes avant et après greffage des sucres. Les polymères ont été caractérisés par RMN 1H, 13C, 29Si, IR et Chromatographie d'Exclusion Stérique. Ces " glycosilicones", à taux de greffage et masses modulables à volonté, ont servi par la suite à stabiliser efficacement des nanoparticules d'or préformées en solution aqueuse y compris à des forces ioniques élevées. Les propriétés réductrices d'amino-sucres utilisés au cours de cette thèse pour la synthèse des glycosilicones ont été mises à profit afin de réaliser la synthèse directe de nanoparticules dans des conditions plus douces que les méthodes de synthèse classique (telle que la réduction de sel d'or avec du borohydrure de sodium). Ces amino-sucres (glucosamine, glucamine) jouent le rôle à la fois de réducteurs, de stabilisants en milieu aqueux. L'avantage de cette méthode réside également en l'utilisation d'un réactif unique non toxique en vue de l'utilisation de ces nanoparticules dans des tests biologiques. La méthode de synthèse se fait en une seule étape et à température ambiante et aboutit à la formation de nanoparticules sphériques avec un bon rendement, mais également, induit des croissances anisotropes conduisant à l'obtention de nanoparticules en forme d'étoiles ou multi-branches avec des rendements très élevés. La taille et le nombre de branches des nano-étoiles ont été modulés en ajustant les conditions expérimentales. Elles ont été caractérisées du point de vue de leur morphologie, stabilité et propriétés optiques (résonance plasmon) par microscopie électronique et spectroscopie UV-visibleCoupling a siloxane chain with various functional groups leads to polymers with new properties combining the flexibility of the chain with the properties of the functional groups. Accordingly, we wanted to study the grafting of saccharide groups on polysiloxane polymers. In the first part of this thesis, a new, smooth, efficient and fast method has been developed for the preparation of linear or hyperbranched polysiloxanes with lateral or terminal sugar groups. The preparation is done without the use of protecting groups for sugars. It avoids the use of acid or alkaline conditions for the deprotection thus preventing the decomposition of the siloxane chains before and after grafting the sugars. The polymers were characterized by 1H, 13C, 29Si NMR, IR and Size Exclusion Chromatography. These "glycosilicones" with grafting rate and weights adjustable at will, were subsequently used to efficiently stabilize preformed gold nanoparticles in aqueous solution even at high ionic strengths. The reducing properties of amino sugars used in this thesis for the synthesis of glycosilicones were used for a direct synthesis of nanoparticles under milder conditions than in conventional synthesis methods (such as reducing the gold salt with sodium borohydride). These amino sugars (glucosamine, glucamine) play the role of both reducing agents and stabilizers in aqueous media. The advantage of this method lies in the use of a single nontoxic reagent which can be useful for using these nanoparticles in biological tests. The one pot synthesis occurs at room temperature and leads to the formation of spherical nanoparticles with a good yield, but also induces anisotropic growth leading to the production of star shaped or multi-branched nanoparticles with very high yields. The size and number of branches of nano-stars were modulated by adjusting the experimental conditions. They were characterized regarding to their morphology, stability and optical properties by electron microscopy and UV spectroscopy
20
Henry, Nathaly. "Conception de polymères à empreintes moléculaires pour l'extraction de principes actifs de produits naturels". Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2028/document.
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L'industrie cosmétique a un recours croissant aux espèces végétales comme sources de principesactifs naturels. Leur extraction nécessite des supports sélectifs tels que les polymères à empreintesmoléculaires (MIP). Les travaux de cette thèse reposent sur le développement de MIP pourl’extraction sélective de la glucosamine, de la fructosazine et de la 2,5-déoxyfructosazine.Dans une première partie, trois approches ont été développées pour extraire la glucosamine par desMIP : l’approche covalente, semi-covalente et non covalente. Pour chacune, les différents paramètresintervenant dans la synthèse des MIP ont été optimisés. Les meilleurs résultats ont été obtenus avecun MIP synthétisé selon une approche non covalente ionique reposant sur la complexation de laglucosamine par un acide sulfonique. Les performances du MIP se sont avérées supérieures à cellesde supports commerciaux et des extractions à partir de végétaux ont été réalisées. Le potentielindustrialisable du MIP a été validé lors de premiers tests à plus grande échelle.Dans une deuxième partie, l’extraction simultanée de la fructosazine et de la 2,5-déoxyfructosazine aété réalisée suite au développement d’un MIP synthétisé selon une approche covalente reposant surla formation d’esters boroniques. Une méthode de synthèse originale est exposée puisque lestemplates ont été formés in situ lors de la polymérisation. Le MIP obtenu s’est avéré sélectif dechaque composé et a permis de purifier et de séparer la fructosazine et la 2,5-déoxyfructosazine dematrices végétales et alimentaires.Tous ces travaux ont été réalisés dans une démarche éco-responsable s’appuyant sur l’emploi desolvants aqueux lors de la polymérisation et de l’extractionThe cosmetic industry uses plants as sources of natural active ingredients. The extraction of theseactive ingredients requires selective extraction method such as molecularly imprinted polymers (MIP)technique. This thesis describes the development of MIP for the selective extraction of glucosamine,fructosazine and 2,5-déoxyfructosazine.In the first part, three approaches were developed to extract glucosamine by MIP technique: thecovalent approach, semi-covalent and noncovalent. For each approach, the various parametersinvolved in the synthesis of the MIP were optimized. The best results were obtained with a MIPsynthesized with a non-covalent ionic approach based on the complexation of glucosamine by asulfonic acid. The MIP exhibits higher performance than commercial media and extractions fromplants were performed. The potential for industrialization of the MIP was validated during initial testson a larger scale.In the second part, the simultaneous extraction of fructosazine and 2,5-déoxyfructosazine wasperformed following the development of a MIP synthesized using a covalent approach based on theformation of boronic esters. An original synthesis method is exposed since the templates were formedin situ during the polymerization. The MIP obtained showed good selectivity for each compound andallowed to separate and purify fructosazine and 2,5-déoxyfructosazine from plant and food matrices.All these works were performed according to an eco-friendly approach based on the use of aqueoussolvents as solvents for polymerization and extraction
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Johnson, Gwenyth Llewellyn. "Registered Dietitian Interest in Complementary Medicine". Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/nutrition_theses/26.
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Complementary and alternative medicine (CAM) has become very popular with populations internationally and in the United States. CAM is defined as “a group of diverse medical and health systems, practices and products that are not generally considered as part of conventional medicine”. CAM is described as having five specific divisions: whole medical systems, mind-body medicine, biologically-based practices, manipulative- or body-based practices, and energy medicine. Recent studies have shown that CAM use is increasing. In the US 33% of the population reported using CAM in 1990, but 1997 usage rates increased to over 41%. The popularity of CAM is one of the reasons for the creation of the National Center for Complementary and Alternative Medicine (NCCAM) by the National Institutes of Health the Federal Government's lead agency for scientific research on the diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine”. NCCAM information was the foundation for this project. The goals of this project are to evaluate the interest of dietitians in Georgia in CAM and introduce participants of this project to a segment of CAM treatments. The primary research question is: Are dietitians in the state of Georgia interested in using CAM as part of their practice? There were three distinct portions to this project; the initial survey of the dietitian participants, the development and use of the introductory CAM lesson, and the evaluation of this lesson and final survey. The data from both the first and second surveys as well as the post test does support a positive answer to the research question, “Are registered dietitians in the state of Georgia interested in CAM? The results clearly indicate an interest from both the survey 1 and survey 2/ post test group. Some may ask, “Is this really of any importance to the dietetics profession?” The answer to this can be found in the nutrition literature. Conducting a topic search of “Complementary and alternative medicine” in three predominant nutrition journals: the American Journal of Clinical Nutrition, The Journal of Nutrition and The Journal of the American Dietetic Association, revealed more than 17,000 articles. These articles range for original research to review of original research to commentary articles evaluating the use of CAM to the dietetics practice. A number of articles addressed the importance of CAM in dietetics education as well as its importance to the practice and reimbursement for services.
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Eleotério, Renato Barros. "Efeito do sulfato de condroitina e glucosamina na reparação de defeitos osteocondrais experimentais no côndilo femoral de cão". Universidade Federal de Viçosa, 2011. http://locus.ufv.br/handle/123456789/5055.
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The aim of this research was to evaluate the influence of chondroprotective veterinary supplement (nutraceutic) composed of glucosamine and chondroitin sulfate in the repair of osteochondral defects induced in femoral lateral condyle of dogs, by clinical, radiographic, macroscopic, histologic and morfometric analysis. We also aimed to test the safety of the supplement with tests of blood glucose, blood count, liver and kidney function, activated partial tromboplastine and time prothrombin time. Fortyeigth adult dogs with body weight ranging from 10 kg to 25 kg were used. They were divided into four treatments (I, II, III and IV), according to the postoperative period of evaluation (15, 30, 60 and 90 days) and each containing six animals. Within each treatment, six animals (GI) received the supplement daily, while the other six formed the control group (GII). No significant differences were observed between groups for each treatment. Therefore, the conditions in which this study was conducted, the chondroprotective did not cause adverse effects and the treated group did not differ from the control on the repair process of such defects.
O presente trabalho teve como objetivo avaliar a influência de um suplemento condroprotetor (nutracêutico) veterinário comercial, à base de sulfato de condroitina e glucosamina, na reparação de falhas osteocondrais induzidas no côndilo femoral lateral de cães, por meio de análises clínica, radiográfica, macroscópica, histológica e morfométrica. Objetivou-se ainda testar a segurança do produto, por meio dos exames de glicemia, hemograma, funções hepática e renal, tempo de tromboplastina parcial ativada e tempo de protombina. Foram utilizados 48 cães adultos, entre 10 e 25 kg de peso corporal e sem raça definida, distribuídos aleatoriamente entre quatro tratamentos (I, II, III e IV), de acordo com o período de pós-operatório (15, 30, 60 e 90 dias) e contendo cada um deles 12 animais. Dentro de cada tratamento, seis animais (GI) receberam diariamente o condroprotetor, enquanto os outros seis constituíram o grupo controle (GII). Não houve diferença significativa entre os grupos de cada tratamento e, portanto, nas condições em que o presente estudo foi realizado, o condroprotetor não ocasionou efeitos adversos e o grupo tratado não diferiu do controle quanto ao processo de reparação dos defeitos.
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Villegas-Peñaranda, Luis Roberto. "Production of Sialic Acid Analogs in Engineered E. coli: Characterization of Amino Sugar Recycling". Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39807.
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This research focused on the study of the amino sugar recycling and sialic acid degradation pathway as a possible entry point for N-acyl glucosamines for the production of sialic acid analogs. Meeting this objective would allow the development of a bacterial strain capable of producing non-natural nonulosonic acids that could be used in the development of medicines, vaccines or useful compounds for the study of interactions between pathogenic organisms and their host.
The first step was to understand how N-acetyl-D-glucosamine-6-phosphate deacetylase reacts to different types of substrates in order to determine its tolerance to the size of acyl groups in acyl amino sugars. This was achieved by studying the enzymatic activity in an in vitro system. We determine that the enzyme has a preference for small and slightly bulky acyl groups. Then, an in silico docking modeling and an in vivo system experiment were carried out. These experiments allowed to confirm the previous results.
The second project was carried out due to the uncertainty of whether the kinase involved in the catabolic pathway would be able to phosphorylate the substrates. By quantifying residual ATP, the high specificity of N-acetyl-D-glucosamine kinase could be verified. This result led us to think about the design of an organic synthesis strategy that would allow the phosphorylation of glucosamine in carbon 6. A simple synthetic route was designed based on the protection of the two most reactive moieties of the amino sugars and the reactivity of the hydroxy group on carbon 6. However, we had problems with the purification step of the final product due to its high polarity.
The next stage of this investigation was to confirm the transformation of GlcNAc into ManNAc. For this, an NMR analysis was designed that would detect the presence of both sugars in the reaction system. The epimerization of ManNAc to GlcNAc was detected successfully. Notwithstanding, the reverse reaction could not be detected. Based on the results obtained in the previous stage, we realized that an error was made in the epimerization reaction since we placed the wrong kinase because we did not take into account its substrate specificity.
Finally, we tried to produce sialic acid analogs in a fermentative system using different genetic variants of Escherichia coli. Two of the expected analogs, Neu5Pr and Neu5nBu, were obtained. In addition, NagA activity towards substrates with small acyl groups was confirmed.
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Wojcik, Karolina. "D-glucosamine as "green" substrate in synthesis of ligands for asymetric catalysis". Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00974873.
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Several ligands derived from D-glucosamine, designed for different catalytic reactions havebeen synthesized. The ligands for homogeneous catalysis based on 1,2-glucodiamine wereprepared, and used in reactions of allylic alkylation, hydrogenation and Michael addition.Supported Aqueous Phase Catalyst (SAPC) system was prepared from D-glucosamine anduse with very good results in Suzuki Miyaura cross coupling reactions. Catalyst was alsorecycled. Attempt to prepare ligands grafted on SBA-silica matrix were made as well asligands containing poly(ethylene) glycol moiety.
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MARRA, ALBERTO. "Reactions d'o-glycosylation impliquant la glucosamine, la galactosamine et l'acide n-acetylneuraminique". Paris 6, 1989. http://www.theses.fr/1989PA066335.
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Plusieurs derives de la d-glucosamine, comportant un groupement p-methoxybenzylidene en position 2 (bases de schiff), ont ete prepares. Leur efficacite vis-a-vis de reactions de glycosylation a ete etudiee. L'application de la reaction de lithiation reductrice a une serie de thiophenylglycosides et glycosyl phenyl sulphones permet d'obtenir les glycals correspondants en rendement eleve. Un de ces glycals a ete soumis a la reaction d'azidonitration. La synthese de deux disaccharides, constituant des fragments du dermatane sulfate, a ete effectuee par glycosylation avec le bromure et le trichloroacetimidate de l'acide l-iduronique et le bromure de l'acide d-glucoronique apportunement proteges. Des tri- et tetra-saccharides sialiles, fragments du pentasaccharide portant la specificite du groupe sanguin cad, ont ete synthetises par des reactions de glycosylation de type koenigs-knorr. Plusieurs thioglycosides de l'acide n-acetylneuraminique ont ete prepares et leur efficacite vis-a-vis de reactions de glycosylation a ete etudiee
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MASSIERE, FREDERIC. "Synthese et evaluation d'inhibiteurs de la glucosamine-6-phosphate synthase d'escherichia coli". Paris 6, 1996. http://www.theses.fr/1996PA066281.
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De nouveaux inhibiteurs potentiels de la glucosamine-6-phosphate synthase (glms), enzyme-cle du metabolisme des microorganismes, ont ete synthetises et testes sur l'enzyme d'escherichia coli. L'analogue thioamide de la glutamine, l'un des deux substrats de la glms, n'est pas reconnu par l'enzyme. En presence de fructose-6-phosphate, l'analogue nitrile de la glutamine est hydrolyse en glutamate et ammoniac, mais cet ammoniac genere n'est pas utilise pour synthetiser de la glucosamine-6-phosphate. Une gamma-glutamyl anilide fluoree, concue pour etre un inhibiteur suicide de la glms, a ete preparee a partir d'acide glutamique et du para-nitrobenzaldehyde. L'enzyme catalyse l'hydrolyse de la liaison amide de cette molecule et une faible inactivation a ete observee. Les possibilites de synthese et la stabilite des gamma-glutamyl glycines alpha-heterosubstituees ont ete etudiees. Deux composes fluores de cette serie, concus pour etre des inhibiteurs suicides de la glms, ont ete prepares a partir de glutamine, d'acide glyoxylique et de para-mercaptobenzaldehyde. Un seul des deux derives possede les caracteristiques d'un inhibiteur suicide
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Richez, Céline. "Caractérisations biochimique et cinétique de la glucosamine-6-phosphate synthase humaine 1". Paris 11, 2007. http://www.theses.fr/2007PA112094.
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La Glucosamine-6-phosphate synthase ou L-glutamine:D-fructose-6-phosphate amidotransférase humaine 1 (Gfat1) est une cible thérapeutique dans les complications pathologiques liées au diabète de type 2. Elle catalyse la première étape de la voie de biosynthèse des hexosamines dont le produit final est l’UDP-N-acétyl-Glucosamine. La protéine contient une étiquette histidine en position interne de sa séquence et est exprimée dans les cellules d’insectes Sf9. Deux tests au format microplaque ont été mis au point pour doser la D-glucosamine-6-phosphate et le L-glutamate pour déterminer les caractéristiques biochimique et cinétique de l’enzyme. L’enzyme recombinante possède des constants d’affinité Km Fru-6-P = 0,98 mM et Km Gln = 0,84 mM similaires à celles décrites pour l’enzyme de foie de rat. Le méanisme cinétique de Gfat1 est de type Bi Bi ordonné, déterminé à partir de l’étude d’inhibition par les produits de réaction. Un criblage de la chimiothèque de l’ICSN a permis d’identifier trois composés qui inhibent spécifiquement l’enzyme humaine, nouvelles pistes pour des molécules anti-diabétiquesHuman L-glutamine: D-fructose-6-phosphate amidotransferase (Gfat1), a recognized target in type 2 diabetes complications, was expressed in Sf9 insect cells with an internal His6-tag and purified to homogenity. This protein catalyses the first step of biosynthesis pathway of hexosamines whose end product is UDP-N-acetyl-Glucosamine. Two different microplate assays quantify D-glucosamine-6-phosphate and L-glutamate were used to analyze the enzyme kinetic properties. The recombinant human L-glutamine: D-fructose-6-phosphate amidotransferase isoform 1 exhibits Michaelis parameters Km Fru-6-P = 0. 98 mM and Km Gln = 0. 84 mM which are similar to the values reported for the same enzyme from liver rat. The kinetic mechanism ordered Bi Bi rapid equilibrium was determined from product inhibition. A screening of data compounds from ICSN allowed discovering three specific inhibitors of human enzyme that provid interesting targets in medicinal chemistry of anti-diabetic compounds
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Gouze, Jean-Noël. "Action antagoniste de la glucosamine sur les effets délétères de l'interleukine-1 ou des compressions mécaniques sur la synthèse des protéoglycanes dans des cultures chondrocytaires". Nancy 1, 2000. http://www.theses.fr/2000NAN12018.
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Thèses en sciences du médicament. Les phases précoces des atteintes articulaires se caractérisent par une rupture de l'homéostasie du cartilage due en particulier à une inhibition de synthèse des composants matriciels. Nos travaux étudient les effets délétères de l'IL-1 et de compressions mécaniques lors de l'atteinte cartilagineuse observée dans un modèle original de chondrocytes en culture. Nous avons dans un premier temps mis en évidence le rôle clé de la GIcAT-I (une enzyme impliquée dans l'élongation de la chaîne des GAGs) dans la baisse de synthèse des PGs. Nous montrons d'autre part que la glucosamine s'oppose aux effets induits par l''IL-I et/ou les compressions mécaniques à la fois sur des enzymes anaboliques, caraboliques, mais aussi sur différents paramètres pro-inflammatoires. Les effets bénéfiques de ce glucide s'expliquent en partie par une action an niveau réceptoriel sut la voie d'activation de NF-kB. Cette étude ameliore les connaissances de l'effet bénéfique de la glucosamine sur le cartilage articulaire arthrosique par l'identification de deux cibles de ce glucide sur la signalisation cellulaire de l'IL-LEarly stages of articular disease are characterized by a breakdown of cartilage homeostasis notably due to a biosynthesis inhibition of matricial components. Our works concerns the IL-1 and mechanical compression deleterious effects in an articular cartilage damage observed in an origjnal model of chondrocyte culture. We first have determined the krey role of GIcAT-I (an enzyme implicated in GAG elongation chain) on the decrease of PG synthesis. Moreover, we have shown that glucosamine reserves the IL-1 mechanical compression-mediated effects on anabolic, catabolic enzymes and on differents pro-inflammatory parameters. The glucosamine beneficial effects can be in part explained by an action at the receptorial level and on activation of NF-kB. This study improves knowledge of beneficial glucosamine effects on articular osteoarthritic cartilage by the identification of two targets on IL-1 signaling pathways
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Broberg, Karl Rufus. "Synthetic approaches towards heparinoid related saccharides and derivatives". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/synthetic-approaches-towards-heparinoid-related-saccharides-and-derivatives(6c1366ba-82dc-43b2-9af3-294ebed56639).html.
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Heparin glycosaminoglycans mediate a range of biological events, including anticoagulation as well as a diversity of cell proliferation and differentiation processes. Heparin saccharides have been shown to act as inhibitors against angiogenesis and metastasis of tumour cells. This thesis describes work developing chemistry towards varying length oligosaccharide sequences with potential to offer variable sulfation patterns. The main synthetic components to this work were contribution to developing scalable syntheses of an orthogonally protected L-Iduronic acid unit and a differentially protected D-glucosamine unit. The synthetic work also evaluated a recently reported diazo transfer reagent, which allowed for earlier placement of azide protection over that of previously developed routes within the group. This provided a cheaper, more atom efficient route towards protected D-glucosamine building blocks. Glycosylation of the developed D-GlcN donor units with the L-Ido acceptor allowed the production of key disaccharides which facilitated an efficient iterative glycosylation strategy towards longer oligosaccharides, ultimately providing a differentially protected pentasaccharide. The project evaluated methods towards generating various dimeric heparin type systems through forming new O4 ether linkages between GlcN residues across various short linker fragments. The most successful of these dimerisations used a methallyl dichloride core which allowed for further derivatisation towards dihydroxylated species, the analysis of which highlighted some interesting proton NMR data. The final aspect of this project began development of chemistry towards non-reducing end-labelled oligosaccharide sequences by implementation of a masked aldehyde unit on the C4 hydroxyl of GlcN synthesised from the allylated GlcN precursor via dihydroxylation chemistry. Incorporation of this moiety (protected as a 1,2-dibenzyl glycol) within both a trisaccharide and a pentasaccharide was achieved. Further development of this chemistry should allow for late step oxidative cleavage to reveal the reactive aldehyde, potentially allowing for attachment of various amine functionalised fluorophores via reductive amination. Radiolabelling of such a species should also be possible through sodium borotritide reduction for example.
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Lemattre, Patricia. "Alkyl oligoéthylène glycols dérivés des alcools de Guerbet : synthèse, utilisations pour la préparation de néoglycolipides et comme ancrage de protéines membranaires". Lyon 1, 1999. http://www.theses.fr/1999LYO10102.
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La synthese des alkyloligoethylene glycols derives des alcools de guerbet a ete realisee en vue de la preparation d'ancrages synthetiques de proteines membranaires et pour la preparation de neoglycolipides derives de la -d-glucosamine. Les methodes de preparation les plus utilisees pour la synthese d'alkylpolyethylene glycols sont des variantes de la methode de williamson, dont nous avons etudie deux approches. La reaction d'alcoolates de composes lipidiques sur des oligoethylene glycols actives n'a pas donne les resultats escomptes pour les alcools de guerbet ; une autre approche a alors ete utilisee : la reaction d'alcools de guerbet actives sur un alcoolate d'oligoethylene glycol. Pour ces syntheses, l'utilisation des tosylates des alcools de guerbet, sous les conditions classiques de williamson, a permis de preparer les alkyloligoethylene glycols desires avec des rendements acceptables en presence d'ethers couronne ou de cryptants. Les -glycosides de la n-acetylglucosamine ont ete prepares selon la methode a l'alkoxycarbonyle avec une excellente stereoselectivite et de bons rendements. L'obtention des glycosides totalement deproteges a necessite neanmoins des amenagements lies a leur faible solubilite. Certains de ces neoglycolipides ont ete ensuite utilises pour des experiences de reconnaissance moleculaire. La fonction hydroxyle des alkyloligoethylene glycols derives des alcools de guerbet a ete activee sous differentes formes afin de realiser un couplage avec une proteine. L'ancrage a ete realise sur la bsa par l'intermediaire d'une cysteine. Le couplage d'un de ces composes apres son incorporation dans des liposomes semble possible, et ouvre la voie a l'ancrage de proteines membranaires.
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Fernandez, Julie Autefage André. "Les Chondroprotecteurs dans le traitement de l'arthrose chez le chien étude bibliographique /". [S.l.] : [s.n.], 2008. http://oatao.univ-toulouse.fr/2085/1/debouch_2085.pdf.
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Welch, Courtney Ann. "Plasma concentration of glucosamine and chondroitin sulfate in horses following an oral dose". Texas A&M University, 2004. http://hdl.handle.net/1969.1/3070.
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This study was conducted to study absorption of glucosamine and chondroitin sulfate and to measure any changes in blood concentration of these compounds following feeding them to horses in different amounts. Six mature mares were used in a replicated 3x3 Latin square designed experiment. The experiment consisted of three 15-day periods, which included 10 days of diet adaptation followed by a 5-day sampling period. Blood was drawn on one day during each sampling period. Horses were fed a control diet (40% hay, 60% concentrate) balanced to meet NRC (1989) requirements for maintenance of mature horses. In one experimental diet, 2.0 g chondroitin sulfate and 5.5 g glucosamine were added to the basal ration at each feeding. In the other experimental diet, 3.5 g chondroitin sulfate and 8.5 g glucosamine were added to the basal ration at each feeding. Following total collections, blood was centrifuged and plasma was harvested and data analyzed for the presence of each compound. Analyses for plasma glucosamine were performed in the Protein and Chemistry Lab at Texas A&M University using HPLC. Chondroitin sulfate in the plasma was analyzed using a color reagent, dimethylmethylene blue, followed by UV spectrophotometry.
There were no significant differences (P<0.05) in the concentration of chondroitin sulfate or glucosamine concentrations in plasma when comparing the three different diets. This leads to a conclusion that these compounds were not absorbed through the intestinal wall into the bloodstream in the same form as they were fed. This poses a question as to whether or not oral forms of these compounds are absorbed and are able to migrate to joints through the blood to improve joint function. With the significant economic impact that products containing chondroitin sulfate and glucosamine are making in the animal nutrition industry, more research is needed to further elucidate actual efficacy of these compounds in diet supplements for horses.
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Copey, Laurent. "Synthèses et applications de nouveaux ligands pyrroliques et méthodologies de synthèse de phosphines P-chirogéniques". Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10259/document.
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Deux thématiques principales ont été étudiées au cours de cette thèse. La première partie porte sur la synthèse de complexes de manganèse dérivés de porphyrines et de salens. L'activité catalytique de ces complexes a été évaluée dans l'époxydation d'alcènes non-Fonctionnalisés. Suite à cette étude, les propriétés électroniques des ligands ont été étudiées, notamment par le biais de la complexation d'anions. Dans une deuxième étape, nous nous sommes intéressés à la synthèse de phosphines P-Chirogéniques. Afin de trouver un substitut à l'éphédrine, couramment utilisée dans ces synthèses, des dérivés du (1S,2S)-2-Aminocyclohexanol et de la D-Glucosamine ont été synthétisés. L'utilisation de groupements sulfonamides a permis l'obtention aisée d'oxazaphospholidines N-Tosylées. L'un ou l'autre diastéréoisomère de cet hétérocycle peut être obtenu en fonction du degré d'oxydation du réactif phosphoré utilisé. Avec cette stratégie, divers oxydes de phosphines ont été obtenus avec de bons rendements et de bonnes énantiosélectivitésThis thesis is divided in two parts. The first part focuses on the synthesis of manganese complexes derived from porphyrins and salens. The catalytic activity of these complexes were evaluated toward the epoxidation of unfunctionalized alkenes. Next, the electronic properties of the ligands were evaluated using their anion binding properties. In a second part, we were interested in the synthesis of P-Chirogenic phosphines. In order to find a surrogate to ephedrine, that is commonly used in those syntheses, derivatives from (1S,2S)-2-Aminocyclohexanol and D-Glucosamine were synthesized. The use of sulfonamides allows the access to N-Tosylated oxazaphospholidines. Both diastereoisomers could be synthesized depending on the oxydation state of the phosphine precursor. Using this strategy, various phosphine oxides were obtained in good yields and enantioselectivities
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Frem, Dany. "Catalyse organique énantiosélective par des oligomères bien définis de chitosane". Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112292/document.
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Des oligomères de taille définie de chitosane ont été préparés et testés en tant qu'organocatalyseurs dans des réactions d'aldolisation énantiosélectives. Les précurseurs de ces catalyseurs sont obtenus en une seule étape par une réaction d'acétolyse contrôlée de la chitine, second polysaccharide le plus abondant. Une méthodologie reposant sur des réactions de glycosylation sous activation micro-ondes a été développée afin de fonctionnaliser la position anomérique de ces oligomères. Ainsi, le triflate de cuivre(II), utilisé en quantité catalytique, s’est révélé être le promoteur le plus efficace pour l’activation de la glucosamine ou du chitobiose peracétylés de configuration α. La sélectivité α des produits glycosylés résultent d’une isomérisation in situ des produits cinétiques β. Des organocatalyseurs se différenciant par leur partie aglycone et par leur degré de substitution ont été synthétisés en peu d’étapes. Les résultats les plus intéressants ont été obtenus avec un dérivé du chitobiose soluble en milieu aqueux. Nous avons montré, qu’en présence d’un co-catalyseur acide, l’acide 4-nitrobenzoïque, la réaction entre la cyclohexanone et le 4-nitrobenzaldéhyde, conduit à l’adduit anti avec un bon excès énantiomérique (89% ee). De plus, nous avons également montré que ce catalyseur pouvait être réutilisé dans plusieurs cycles catalytiques sans perte de sélectivitéThe catalytic behaviour of size-defined chitosan oligomers has been evaluated for asymmetric aldol reactions. These oligomers were obtained from chitin, which is one of the most abundant naturally occurring polymers, as a renewable starting biomolecule. Thus, controlled depolymerization of chitin was carried out by acetolysis providing per-O-acetylated N-acetyl-α-D-glucosamine oligomers with a polymerization degree from 2 to 4. To investigate the influence of the aglycon moiety, we developed a Lewis acid-promoted glycosylation reactions under microwave irradiation. Thus, a catalytic amount of copper(II) triflate proved to be the most effective promoter for the activation of α-per-O-acetylated glucosamine oligomers, which are considered as poorly reactive substrates, to selectively obtain α-glycosylated compounds. This selectivity results from in situ isomerization of kinetic β products. Chitosan-based catalysts, which differ in the distribution pattern, were synthesized in a few steps. The most promising results were obtained with a chitobiose derivative, which efficiently catalyzed the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, in the presence of 4-nitrobenzoic acid as a co-catalyst, in water, providing the anti-adduct in high yield with good enantioselectivity (89% ee). In addition, this homogeneous organocatalyst can be reused in several cycles without loss of catalytic activity
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Westling, Camilla. "N-Unsubstituted Glucosamine Residues in Heparan Sulfate and Their Potential Relation to Alzheimer's Disease". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3866.
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Watson, Nicol D. "A biochemical and proteomic analysis of glucosamine-treated, insulin-resistant cultured human muscle cells". Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432496.
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Mbongo, Mounoume Aimé. "Synthèse de c-glycosides et application aux dérivés de la n-acetyl-d-glucosamine". Amiens, 1992. http://www.theses.fr/1992AMIES029.
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Dans ce travail, nous avons réalisé la synthèse de c-glycosides en utilisant deux voies de synthèse. La première voie est l'étude de la réaction de Wittig-Horner-Emmons-Wadsworth sur la n-acetyl-d-glucosamine et ses dérivés, puis sur le d-maltose. Nous avons obtenu sélectivement les alpha-c-glycosides. La deuxième voie consiste à l'application d'une nouvelle réaction one pot de type Wittig en présence de zinc, de tri-n-butyl phosphine et de bromoacétate de méthyle sur les dérivés de la n-acetyl-d-glucosamine. Nous avons obtenu de manière stéréospécifique les béta-glycosides. Le remplacement du bromoacétate de méthyle par le bromoacétonitrile ou le chlorométhylphenylsulfure nous a permis d'obtenir respectivement, de manière stéréosélective des c-glycosides nitriles et des glycosylsulfures insaturés avec des rendements satisfaisants
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Chierici, Sabine. "Synthèse de néoglycolipides de la β-D-glucosamine et étude de leurs assemblages supramoléculaires comme modèles de reconnaissance". Lyon 1, 1997. http://www.theses.fr/1997LYO10171.
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L'acces a une meilleure connaissance des phenomenes de reconnaissance des residus saccharidiques des glycoconjugues membranaires necessite de disposer de modeles d'etude organises (vesicules ou films lipidiques) reproduisant les contraintes rencontrees dans les milieux biologiques. Divers neoglycolipides ont dans ce but ete synthetises et leur capacite a s'autoorganiser en milieux aqueux a ete mise a profit pour fournir des assemblages modeles d'etude de l'organisation supramoleculaire des sucres a la surface des membranes cellulaires. Les glycosides synthetises comportent des fractions lipidiques mono, bicatenaires dissymetriques (squelette de guerbet) ou symetriques (prealablement prepares a partir d'un squelette pentaerythritol) et un bras espaceur hydrophile (de type oligoethyleneglycol) de longueur variable entre la tete saccharidique et la partie lipidique. Differentes methodes de couplage du bras et differents donneurs de glycosylation ont ete utilises pour acceder a ces composes. L'organisation supramoleculaire des neoglycolipides synthetises, en liposomes en presence de phospholipides ou en monocouches a l'interface air-eau, a ensuite ete etudiee. L'incorporation des neoglycolipides cholesteriques dans des liposomes unilamellaires de phosphatidylcholine a ete realisee et caracterisee par double marquage radioactif. L'influence de l'ancre cholesterol et de longueur du bras espaceur oligoethyleneglycol sur la stabilite, la taille, la permeabilite et la reconnaissance de ces vesicules mixtes par une lectine specifique (wheat germ agglutinin) ont egalement ete etudiees. Ces travaux ont permis de montrer la stabilite de ces systemes neoglycolipidiques et surtout la necessite d'un bras espaceur d'au moins trois maillons ethyleneglycols pour que la reconnaissance sucre-lectine ait lieu. Le comportement interfacial d'un neoglycolipide gemini derive du pentaerythritol a egalement ete etudie et des monocouches stables avec ce compose pur ou en melange avec du cholesterol ont pu etre realisees, revelant un comportement similaire a celui des phospholipides.
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Lerivrey, Jacques. "Étude de la complexation des systèmes métal - S-triazines - D-glucosamine : mise en évidence de complexes ternaires". Lille 1, 1985. http://www.theses.fr/1985LIL10123.
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L'objectif principal de ce travail est l'étude de la complexation du système ternaire cuivre (II) - prométone - D-glucosamine en solution aqueuse dans le but de comprendre le mécanisme d'assimilation des herbicides par les plantes. L'étude préliminaire des systèmes binaires Cu(II) - prométone et Cu (II) - D-glucosamine s'est avérée nécessaire. Nous avons mis en oeuvre une technique potentiométrique et développé des programmes de traitement de données expérimentales. Les résultats potentiométriques sont corroborés par différentes techniques spectroscopiques qui précisent la nature des liaisons impliquées dans les complexes. La prométone (PR), herbicide de la famille des s-triazines, conduit avec l'ion cuivrique à la formation d'un complexe stable de type CuL2. Avec la D-glucosamine (GA), sucre aminé simple, nous avons mis en évidence des complexes du type CuL2 et CuL2H-2. L'étude du système ternaire Cu(II) - PR - GA montre la formation du complexe mixte Cu(PR)(GA), très stable dans la zone des pH neutres. L'herbicide préalablement complexé avec le cuivre (II) peut réagir avec les sucres aminés présents dans les parois cellulaires des plantes et faciliter son assimilation. D'autre part, nous avons étudié l'influence des substituants de la molécule de 1, 3, 5 s-triazines dans sa complexation avec Cu(II) et l'influence de la nature du métal sur les phénomènes de coordination avec la D-glucosamine.
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Bintein, Fabrice. "Influence du facteur entropique en glycobiologie : synthèse de ligands multivalents des sélectines, de flexibilité variable". Paris 11, 2002. http://www.theses.fr/2002PA112154.
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La réponse inflammatoire fait intervenir une séquence de trois processus de reconnaissance cellulaire. Le premier processus, impliquant les sélectines et leurs ligands oligosaccharidiques naturels, peut être bloqué par l'intermédiaire de ligands multivalents de haute affinité. Ainsi, des pathologies liées à une inflammation chronique ou aigue͏̈ pourraient être traitées. Les facteurs influençant la coopérativité dans les systèmes multivalents ont conduit à la synthèse de ligands multivalents de structures contraintes, composés du motif sialyl Lewis-x. Ainsi, la synthèse de deux ligands trimèriques et deux ligands dimèriques, dont les unités sialyl Lewis-x sont liées au pentaérythritol, de flexibilité variable a été envisagée. La stratégie consiste en la synthèse d'un trimère ou dimère de glucosamine qui est ensuite cyclisé intramoléculairement. L'introduction des unités sucres restantes par voie enzymatique permet l'obtention du ligand désiré. Le premier de ces trimères, comportant un bras espaceur en position six, n'a pu être déprotégé par les méthodes classiquement utilisées. Un second trimère et un dimère, dérivés de la glucosamine, de structures proches, ont été correctement fonctionnalisés en unité 2-amino acide glucuronique. Mais, les précurseurs des ligands trivalents et divalents de structures rigides n'ont pu être isolés après l'étape de cyclisation intramoléculaire impliquant la création de liaison amide. Un second ligand divalent de sialyl Lewis-x de structure rigide a été obtenu selon une stratégie faisant intervenir le couplage d'un dimère de glucosamine, possédant deux fonctions amines libres, et le chlorure de succinyle, suivie d'une séquence enzymatique impliquant trois glycosyltransférases. La synthèse du ligand divalent de sialyl Lewis-x de structure flexible a également été réalisée afin d'apprécier le gain ou la perte d'activité, apporté par la rigidité de ces ligands, vis à vis des sélectinesThe inflammatory response occurs via three sequential cellular recognition processes. The first process, involving selectins and their natural ligands, may be blocked with high affinity multivalent ligands. Thus, acute or chronic inflammatory diseases may be treated. Factors which influence cooperativity in multivalent systems prompted us to synthesize multivalent ligands with constrained structures made up of sialyl Lewis-x units. The synthesis of trimeric and dimeric ligands, in which sialyl Lewis-x units are linked by a pentaerythritol spacer, with variable flexibility was considered. The strategy relies on the synthesis of a glucosamine trimer or dimer which is then cyclised. The introduction of the remaining sugar units by an enzymatic route affords of the desired ligand. The first glucosamine trimer, including a spacer arm linked at position six, could not be deprotected by classical methods. A second trimer and a dimer, both derived from glucosamine with a similar structure were successfully converted to 2-amino glucuronic acid units. Unfortunately, the precursors of divalent and trivalent ligands with rigid structures could not be isolated after the intramolecular cyclisation step involving the amide bond formation. A second divalent sialyl Lewis-x ligand, with a rigid structure, was obtained according to a strategy based on the succinyl chloride-mediated coupling of a glucosamine dimer, which possesses two free amines. This was then completed by an enzymatic sequence involving three glycosyltransferases. The synthesis of the sialyl Lewis-x divalent ligand was also performed in order to estimate the benefit or the loss of activity towards selectins brought about by ligand rigidity
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Zhang, Xin. "Evaluation of hydrophobically modified low molecular weight chitosans as novel delivery vectors for non-viral gene therapy". Université Louis Pasteur (Strasbourg) (1971-2008), 2008. http://www.theses.fr/2008STR13003.
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Le succès de la thérapie génique dépend du développement de vecteurs capables de délivrer des gènes dans les cellules. Parmi les vecteurs non viraux, les chitosans sont biocompatibles et peu toxiques. Nous avons développé des chitosans de faible masse moléculaire, greffés par des chaînes hydrophobes (HM-LMW-chs) et présentant des propriétés de détergent. HM(3%)-LMW-Ch forme avec l’ADN de petites particules positivement chargées, résistantes aux nucléases et interagissant peu avec le sérum. Ces particules sont efficacement internalisées, peu toxiques pour les cellules et après administration systémique, délivrent efficacement des gènes dans des reins de souris Par ailleurs, nous avons développé un nouveau chromophore à forte absorption biphotonique (TPA). Une fois conjugué au PEI, ce nouveau chromophore apparaît être un outil efficace pour marquer les nombreuses polyamines utilisées en transfection non-virale et pour caractériser leurs complexes avec l’ADNThe success of gene therapy depends on the development of vectors able to deliver therapeutic genes into the cells. Among the non-viral vectors, chitosans are interesting since they are biocompatible and low toxic. We developed hydrophobically modified low molecular weight chitosans (HM-LMW-chs) that exhibit surfactant-like properties. HM(3%)-LMW-ch forms with DNA small positively charged particles that are resistant to DNases and nucleases and marginally interact with serum components. Moreover, these particles are efficiently internalized in cells and low toxic. After systemic administration, DNA complexes with HM(3%)-LMW-ch efficiently deliver genes in mice kidneys. Moreover, we developed a new two-photon absorbing (TPA) chromophore for two-photon imaging and conjugated it with PEI. The chromophore appears as an adequate tool to label the numerous polyamines used in non-viral gene delivery and characterize their complexes with DNA in two-photon applications
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Cromer, Megan. "Evaluating Structural Disease Progression in Knee Osteoarthritis with MRI". Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9923.
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Evaluating Structural Disease Progression in Knee Osteoarthritis with MRI Knee osteoarthritis (OA) is highly prevalent in the ageing population. OA is a slowly progressive debilitating disease which impacts negatively on quality of life. Economically, there is a substantial cost to the community through the loss of productive work hours and cost of health care, including joint replacement surgery (Huskisson, 2008). As there is no known cure for knee OA, treatment strategies are two-fold and are aimed at improving joint functionality whilst providing symptomatic relief (Harvey & Hunter, 2010). The marketplace is saturated with dietary supplements purporting to support cartilage health and provide a measure of symptomatic relief. Many people with OA use the commonly available dietary supplements glucosamine sulfate and chondroitin sulfate hoping to avail themselves of the perceived therapeutic benefits. Previous trials evaluating glucosamine sulfate and chondroitin sulfate supplements have provided no definitive evidence of their beneficial use in terms of structural disease modification. The majority of trials have mostly used radiographically-based primary outcome measures; however, due to the increased availability and proven diagnostic performance of Magnetic Resonance Imaging (MRI) in OA, its use in providing an evaluation of these supplements appears warranted. This research had three main areas of focus. An experiment was undertaken to validate the use of an unspoiled fat-suppressed gradient echo sequence for use in clinical trials to provide accurate cartilage volume measurements. Following on from this, an evaluation of analysis techniques using quantitative MRI data was performed. This evaluation included the application of ordered values of cartilage thickness changes and a subsequent comparison of the sensitivity of quantitative MRI (qMRI) techniques in detecting disease progression relative to the traditional standard measures from conventional radiography. Lastly, a randomised trial was undertaken in order to evaluate the possible effects of glucosamine sulfate and chondroitin sulfate compared to a placebo on the rate of structural disease progression in OA. The primary outcome measures were based on MRI-derived data of disease progression, including cartilage volume and thickness changes, along with cartilage T2 mapping to provide quantitative measures (T2 relaxation rates) of the extracellular matrix integrity. This work described the first application of T2 mapping in an evaluation of the dietary supplements glucosamine sulfate and chondroitin sulfate. This work validated the use of an unspoiled gradient echo sequence applicable for use in providing datasets for cartilage volume measurements, with very high interscan reproducibility for cartilage quantification. MRI combined with an ordered value analysis was found to be a more sensitive analysis technique in detecting disease progression in OA than the standard measure of joint space narrowing from radiographs. These findings support the future application of ordered values in the analysis of qMRI data. The preliminary results from the randomised trial showed there were no statistically significant definitive benefits from the use of glucosamine sulfate or chondroitin sulfate supplements in slowing structural disease progression in OA, as assessed by MRI-derived cartilage volume and thickness changes and cartilage T2 relaxation rates over a two year period.
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Santos, Maura Zubiaurre dos. "DERIVADOS DA GLUCOSAMINA: SÍNTESE E ATIVIDADE BIOLÓGICA". Universidade Franciscana, 2010. http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/246.
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In the present work, several compounds derived from monosacharide D-Glucosamine were synthetized. These compounds were used successfully against gram-positive and gram-negative microorganisms. In the synthesis of compounds, classical methods in organic chemistry were used.The products were readily prepared from D-Glucosamine in few easy steps. In the first step, we have obtained he imine derivatives 2a or 2b. The resultant imines were protected in the OH groups at C1, C3, C4 and C6 positions with acetyl group. Selective desprotection of C2 aminogroup and coupling with cmnamic acid fford compound 5. All compounds were tested as antimicrobial agents against gram-positive and gram-negative microorganisms. Best results were obtained when compound 2b was used.
No presente trabalho, foram sintetizados vários compostos derivados da D-Glucosamina. Estes compostos foram usados com sucesso contra microorganismos grampositivos e gram-negativos. Na síntese dos compostos, foram utilizados métodos clássicos em química orgânica. Os produtos foram facilmente preparados a partir da D-glucosamina em poucas etapas. Na primeira etapa, foram obtidas as iminas derivadas 2a ou 2b. As iminas resultantes foram protegidas nos grupamentos OH ligados nas posições C1, C3, C4 e C6, por grupos acetila. Desproteção seletiva do grupamento amino ligado na posição C2, e posterior acoplamento com ácido cinâmico, forneceu o composto 5. Todos os compostos foram testados como agentes antimicrobiannos contra microorganismos gram-positivos e gram-negativos. Os melhores resultados foram obtidos quando o composto 2b foi utilizado.
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Thie, Norman Michael Reinhold. "Evaluation of glucosamine sulphate and ibuprofen for patients with temporomandibular degenerative joint disease with pain". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0008/MQ59887.pdf.
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goyal, Navneet. "Synthesis and biological evaluation of aeruginosin based compounds and self-assembly of glucosamine based compounds". ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/1395.
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Aeruginosins are a family of marine natural products containing mostly non-proteogenic amino acids. These compounds contain a common 2-carboxy-6-hydroxy-octaindole (Choi) rigid bicyclic structure. Many aeruginosins are inhibitors for enzymes involved in the blood coagulation cascade, such as thrombin and Factor VIIa. In order to understand the structure activity relationship (SAR) of the aeruginosins and to discover novel anticoagulants with potentially improved inhibitory and pharmacokinetic properties, in the first part of my thesis I have discussed, synthesis of a series of novel analogs of aeruginosin 298-A, in which the Choi will be replaced with L-proline and oxygenated Choi analogs, and the Argol is replaced with various other functionalities. The preparation of oxygenated Choi analogs starting from glucose using a new method has been discussed.
In the second part of my dissertation, I have discussed the design, synthesis and self–assembly of glucosamine based hydro and organogelators. Carbohydrate-based low molecular weight gelators are an interesting class of molecules with many potential applications. A series of amides and ureas were prepared from the protected D-glucosamine from the corresponding acid chloride and isocyanates. The self-assembling properties of these compounds were studied in several solvents, including water and aqueous solutions. Most of these compounds were found to be efficient low molecular weight hydrogelators (LMHGs) for aqueous solutions. The preparation and characterization of these compounds will be elaborated.
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Jui-Wen, Hsieh. "Production Kinetic of Glucosamine by Microorganism". 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0009-2707200616093800.
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Hsieh, Jui-Wen y 謝睿文. "Production Kinetic of Glucosamine by Microorganism". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/66255391996107076397.
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碩士元智大學
化學工程與材料科學學系
94
Glucosamine is an amino-monosaccharide and one of the basic constituents of Chitin and Chitosan. Glucosamine is the major component of human inter-articular lubricant connective tissue. It can repair and rebuild the damaged cartilage and it also can cure the disease of osteoarthritis. The objective of this work is to study the parameters affecting the production of glucosamine hydrochloride by microbial fermentation and to obtain the method of separation and purification of glucosamine hydrochloride.This study uses four funguses Rhizopus oligosorus BCRC 31996, Monascus purpures BCRC 31499, Monascus pilosus BCRC31527 and Aspergillus sp. BCRC31742 to product glucosamine hydrochloride by using fermentation.Three parts were discussed in this study.First is the kinetic and strategy by flask culture which conditions include kinds of fungus, mediums, pH value, and carbon and nitrogen source.The experimental result shows that the glucosamine concentration had an optimum value and was 3428mg/L by using Aspergillus sp. BCRC31742 culture in GP medium, the pH controlled an important rate in culture. Second, the kinetics and strategoy by fermenter culture that the factors were pH value, incubation time and carbon and nitrogen source in the 4L fermentor fermentation.The result shown the glucosamine concentration was 2311mg/L; biomass, 10.1g/L; content, 229(mg/g biomass); yield, 92.4mg/g of carbon source; productivity, 13.8mg/L×h-1 that Aspergillus sp. BCRC31742 was incubated in GP medium. Third is the part of analysis and purification of glucosamine. The glucosamine was analyzed with 1-naphthyl isothiocyanate (NITC) as derivatizing agent. The reaction was carried out in pyridine at 50oC for 1 h. The derivative was analyzed of High Performance Liquid Chromatography. The precision of glucosamine is below to 1.69% and the accuracy is to 2.73%. Purify method is the dry cell reacting with 6N HCl at 100oC for 24 h, then neutralization with NaOH to pH 7 to obtain glucosamine hydrochloride aqueous solution. The purity of glucosamine is from 2.29% to 13.4% after the purification process containing depigmentation and condensing by Rotary Evaporator.
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Chou, Lien-Yu y 周濂宇. "Glucosamine Enhancement on Animal Cognitive Function". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/dp943u.
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Chen, Chun-wei y 陳俊瑋. "Programmable one-pot synthesis of poly glucosamine". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42381533604456258351.
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碩士國立臺灣大學
化學研究所
99
Nucleic acids and proteins are the polymers of linear structure in nature. They can be synthesized via chemically automatic synthesis. However, saccharides are usually branched and very complex in structure. Till now, there is no automatic machine available for saccharides synthesis. To tackle this problem, a new synthesis strategy based on the different RRV of thioglucosides in a programmable one-pot approach has been developed. According to the previous studies, the RRV value is varied by changing amino protecting groups. There were eight different amino protecting groups of thioglycosides which had been synthesized in this thesis, and all of their RRV values were different in each other. Thereby, we confirmed that the RRV value is changed by different amino protecting group indeed. By the one-pot synthesis, there are some trouble in glycosylation about Boc group. It is not suitable donor for glycosylation as the Boc group will be removed in acid condition. However, trisaccharide could be synthesized by compound 14, compound 18 and compound 21. Therefore, V we want to get more polymers as many as possible in the future and it will be a new strategy for the synthesis of poly N-Acetylglucosamine.
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Chuang, Kun-Han y 莊昆翰. "THE ROLES OF GLUCOSAMINE IN LUNG PATHOPHYSIOLOGY". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/36926312671995191205.
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博士國立陽明大學
生理學研究所
101
Acute phase of lung inflammatory diseases, such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), is usually accompanied with disruption of alveolar-capillary barrier and induction of inflammatory-related cytokines and chemokines. Glucosamine, a natural occurring amino monosaccharide highly concentrated in connective tissues, is a joint supplement widely used in the treatment of arthritis. Recently, glucosamine has begun to be considered the potential anti-inflammatory properties to treat the other inflammation disease and anti-cell proliferation abilities to affect cell physiological activities. Nevertheless, the roles of glucosamine in lung pathology and physiology as well as the involved molecular mechanisms have not been well characterized. Our study aims to clarify how glucosamine plays an anti-inflammatory role in response to bacterial endotoxin and the additional possible toxicity on cellular proliferation. Using rat lung inflammation model caused by intratracheal instillation of LPS, pulmonary edema and polymorphonuclear neutrophil (PMN) infiltration, as well as the production of inflammatory cytokines (TNF-alpha, IL-1 beta and IFN-gamma), chemokines (CINC-1, MIP-2 and MCP-1) and nitric oxide (NO)/inducible nitric oxide synthase (iNOS) in alveolar space and/or lung parenchyma, were noted to be mitigated by glucosamine. Using a rat alveolar epithelial cell line L2, cytokine mixture (cytomix)-regulated expression of chemokines (CINC-1 and MIP-2) and NO/iNOS was also suppressed by glucosamine. In addition, we further to prove that glucosamine-reduced NO/iNOS is through down-regulation of NF-kappaB signaling cascades. Furthermore, we also uncovered that glucosamine suppressed cellular proliferation, and induced cell cycle arrest and late apoptosis in human alveolar epithelial cells (A549) and bronchial epithelial cells (HBECs). Moreover, we found an inhibitory effect on phosphorylation of retinoblastoma (Rb) protein and modification on expression of cell cycle-related regulators (p21, p27, p53 and HO-1). In addition, glucosamine attenuated p21 protein stability via the proteasomal proteolytic pathway, as well as inducing p21 nuclear accumulation. Taken together, glucosamine appears to act as an anti-inflammatory role in LPS-induced lung inflammation, at least in part, by targeting to the NF-kappaB signaling pathway, and an inhibitory molecule on cell proliferation through apoptosis and cell cycle disturbance with a halt at G0/G1 phase, which is partly mediated by the reduction in Rb phosphorylation together with modulation of p21, p53 and HO-1 expression, and nuclear p21 accumulation.