Дисертації з теми "Glycan derivatives"
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1
Williams, Matthew. "The development of S-glycosylcysteine derivatives for use in glycan-binding assays." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25655.
Повний текст джерелаАнотація:
This dissertation concerns the development of a synthetic route towards novel cysteine-based glycan-binding probes, for incorporation into glycoarrays and or similar applications used in assays of glycan-recognition phenomena. The need to systematically characterize the glycome and decipher the range of glycosylation patterns found in living cells, has prompted the development of molecular tools such as glycoarrays and related systems for immobilizing defined carbohydrate structures. The preparation of these probes requires access to building blocks where the core structure has defined glycans together with appropriate linkers, and the amino acid cysteine is explored here as one such structure. In particular, this dissertation describes the synthesis of a S-glucosylcysteine derivative SGC, or methyl N-(6-aminohexanoyl)-S-(β-D-glucopyranosyl)-L-cysteinate trifluoroacetate 67, as well as its 2-acetamido analogue SAGC, or methyl N-(6-aminohexanoyl)-S-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-L-cysteinate trifluoroacetate 74. The first approach involved initial preparation of N-(4-azidobutanoyl)-L-cysteine 12 and attempted reaction of this with 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose 3 to form the initial target of this dissertation, bis-glucoside 13. This was not successful, but repetition of the reported reaction involving the use of N-acetyl-L-cysteine 4 provided a modest yield of partially purified bis-glucosyl cysteine (BGC, 1). A mechanism for this one-pot, sequential bis-glucosylation is proposed. The limitations of the one-pot procedure led to investigation of alternative methods for the step-wise introduction of sugar units to the cysteine core. For this purpose the cysteine derivative, methyl N-(6-((tert-butoxycarbonyl)amino)hexanoyl)-L-cysteinate 40, was prepared and reacted with 3 to obtain a fully protected precursor of the target SGC. However, inefficiencies in this procedure led to investigation of an alternative strategy for preparation of SGC.
2
Garg, Monika [Verfasser]. "Conformational Analysis and Application in Diagnostic of Glycosylphosphatidylinositol Glycan Derivatives / Monika Garg." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1155761057/34.
Повний текст джерела
3
Puliti, Elisa. "Role of sphingosine 1-phosphate metabolism and signalling in skeletal muscle atrophy and fibrosis." Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1195603.
Повний текст джерелаАнотація:
In the last 30 years, multiple roles of S1P have been demonstrated in the regulation of skeletal muscle biology. The presented study is focused on the role of S1P metabolism in myogenic differentiation, where SPL was found playing a crucial role in regulating S1P cellular levels and responsible for onset of myogenic program. The role of S1P axis was also confirmed in skeletal muscle atrophy induced by TNF-alpha. S1P signalling pathwayplays a crucial role in the development and maintenance of the fibrotic process. New S1P3 antagonists were tested to antagonise the receptor involved in fibrosis, and new SK inhibitors have been designed on the base of PF-543, with the aim to develop glycohybrids as potential pharmacological tool in skeletal muscle fibrosis. The metabolism of S1P appears a promising drug targets for pharmacological therapies in skeletal muscle repair.
4
Gruškienė, Rūta. "Cationized and poly(ethylene glycol) modified chitosan derivatives and nanoparticles." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100702_105158-57314.
Повний текст джерелаАнотація:
The main aim of this work was to synthesize water-soluble chitosan – methoxy poly(ethylene glycol) (MPEG) graft copolymers and cationized chitosan derivatives of various structure and desirable graft density, and to study their properties. Novel chitosan-MPEG derivatives with different degree of substitution of chitosan were prepared for the first time by “click” chemistry. Several new schemes of the synthesis of chitosan-MPEG and additionally cationized chitosan derivatives were suggested based on protection of amino functionality by using chitosan-dodecyl sulphate complexes. Additional cationization of chitosan through its hydroxyl groups in alkaline medium enabled to prepare chitosan derivatives with very high charge density. A method of enzymatic hydrolysis of the cationized chitosans was proposed which allowed a tenfold decrease of the molecular weight of chitosan derivatives. Modification of chitosan by tartaric, citric or adipic acid yielded chitosan nanoparticles. Further modification of chitosan nanoparticles by dithiobenzendicarboxylate resulted in RAFT macroinitiators used as precursors of functionalized nanoparticles.Pagrindinis šio darbo tikslas buvo susintetinti vandenyje tirpius norimos struktūros bei pakeitimo laipsnio skiepytuosius chitozano – polietilenglikolio (MPEG) kopolimerus bei katijonizuotus chitozano darinius ir ištirti jų savybes. Įvairaus pakeitimo laipsnio chitozano-MPEG skiepytieji kopolimerai susintetinti vykdant „klik“ chemijos reakcijas. Pasiūlyti nauji chitozano-MPEG bei papildomai katijonizuoto chitozano sintezės būdai, chitozano aminogrupių apsaugai naudojant chitozano kompleksus su dodecilsulfatu. Dalinai katijonizuoto chitozano darinius papildomai katijonizuojant šarminėje terpėje, gauti chitozano dariniai, turintys labai didelį krūvio tankį. Pasiūlytas katijonizuoto chitozano fermentinės hidrolizės metodas, kurį naudojant chitozano darinio molekulinę masę lengvai galima sumažinti dešimtimis kartų. Chitozaną modifikuojant vyno, citrinų arba adipo rūgštimis, susintetintos nanodalelės. Prie chitozano nanodalelių prijungus (4-cianpentano rūgšties)-4-ditiobenzenkarboksilatą, susintetintas makroiniciatorius gyvybingajai radikalinei polimerizacijai RAFT metodu.
5
Peters, Scott O. "Induced pi-facial discrimination in the alkylation of chiral derivatives of glycine." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0014/MQ52745.pdf.
Повний текст джерела
6
Idziak, Irene. "Synthesis of amide-backbone DNA analogues and their poly(ethylene glycol) derivatives." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40145.
Повний текст джерелаАнотація:
Thymidine dimers 16 and 18, connected by amide or N-methylamide linkages, have been prepared. The dimers were incorporated into normal strands of DNA by solid phase synthesis. Thermal denaturation studies, using complementary single-stranded RNA, indicated that these modifications caused no destabilization of the DNA-RNA duplex.The block synthesis of amide-linked homotetramer 30 is described. The synthesis of the corresponding octamer could not be verified because of lack of solubility. One by one homologation was found to be a suitable method for the preparation of N-methylamide analogues.
Poly(ethylene glycol), covalently attached to the 3$ sp prime$ or 5$ sp prime$ end of amide-backbone thymidine homopolymers, was found to greatly increase their solubility. The poly(ethylene glycol) simultaneously served as a soluble solid support for the homologation reactions.$ sp*$ ftn$ sp*$Please refer to the dissertation for diagram.
7
Carter, James. "A New Synthetic Pathway Towards Legionaminic Acid." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/381511.
Повний текст джерелаАнотація:
This thesis describes the results of a PhD project aimed at researching a new synthetic
pathway towards legionaminic acid analogues. Legionaminic acid is a bacterial family of
nonulosonic acids expressed in a terminal position on the flagellar glycans and are considered
to be a virulence factor in the pathogenic bacteria that possess them. At the outset of this
project several examples of Leg synthesis had been published. Whilst three syntheses of Leg
derivatives have been published while the research described in this thesis was being carried
out, the potential of all the published syntheses of Leg to efficiently generate C-7 analogues
is very limited. There are a number of C-7 analogues of legionaminic acid that occur in
nature, and additionally it is the functionality at C-7 which primarily separates the bacterial
nonulosonic acids from the those found in animals (in addition to being 9-deoxy). It was
therefore the goal of this project to develop a synthetic chemical pathway that is adaptable
towards a number of C-7 analogues of legionaminic acid, and potentially other analogues
that may be considered of value. It was also key to our approach that we were able to produce
these analogues of legionaminic acid from a common precursor.
Chapter one of this thesis introduces in detail the literature background of the nonulosonic
acids, in particular the bacterial nonulosonic acids pseudaminic acid, legionaminic acid, and
the recently discovered acinetaminic acid. It discusses the natural occurrence of these
molecules and gives a complete overview of all existing synthetic pathways: chemical,
enzymatic, and chemoenzymatic.
Chapter two describes our initial approach towards the synthesis of legionaminic acid and
7-epi-legionaminic acid. N-Acetylneuraminic acid was selected as the starting material due
to its commercial availability and structural similarities to legionaminic acid. The
transformations required to convert Neu5Ac to legionaminic acid were the deoxygenation of
carbons seven and nine, and the introduction of an acetamide to carbon seven. We based our
initial approach on the synthesis of 8-epi-pseudaminic acid previously completed in our
group. To this end, Neu5Ac was selectively protected to leave the only free hydroxyl group
at carbon seven, which was activated and displaced with a nitrogen nucleophile. The
remainder of the approach consisted of the removal of the protecting groups, acylation of the
C-7 nitrogen, and deoxygenation of carbon nine, however the deoxygenation step provided us with insurmountable difficulties.
In chapter three, the investigation into the synthesis of Leg2en analogues is discussed.
Analogues of nonulosonic acids with a double bond between carbons two and three have
proven to be of value in the past, and with the discovery of a putative glycohydrolase enzyme
for pseudaminic acid, Leg2en and Pse2en analogues could well prove to be just as valuable.
An analogous approach to that discussed in chapter 2 is taken, with the difference being that
Neu5Ac is converted to Neu5Ac2en prior to selective protection and the introduction of the
C-7 nitrogen. Once again, the acetamido functionality was successfully introduced to carbon
seven, but the deoxygenation of carbon nine could not be accomplished.
In chapter four, a revised approach towards legionaminic acid and 7-epi-legionaminic acid is
described. This approach avoided the previously encountered problems with C-9
deoxygenation by performing it early in the synthesis and introducing the nitrogen
functionality to C-7 of 9-deoxy-Neu5Ac. With this new approach, 7-epi-legionaminic acid
and legionaminic acid were both successfully synthesised, with the functionalisation of the
C-7 nitrogen step being performed at the very end of the synthesis, prior only to the removal
of protecting groups. This therefore allows for the investigation into a number of different
functionalisation steps that could be performed on the protected 7-amino-legionaminic acid
substrate.
The final chapter, chapter five, details our investigations into an interesting and important
by-product that we isolated during the activation of the C-7 hydroxyl on multiple substrates.
This by-product was identified as a dihydro-1,3-oxazine derivative, which had formed
between carbon seven and the acetamide of carbon five. We explored the different conditions
under which this by-product formed and found that we could control relatively well whether
the C-7 activated Neu5Ac would convert to the oxazine by changing the base used, and in
what proportions. We also investigated opening this oxazine by-product, with the hope that
we could use its inverted stereochemistry as an avenue towards legionaminic acid stereochemistry, which we were eventually able to do.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Institute for Glycomics
Science, Environment, Engineering and Technology
Full Text
8
Bright, Andrew G. "Mechanistic Insights into the Stabilisation of Biopharmaceuticals using Glycine Derivatives. The Effect of Glycine Derivatives on the Crystallisation, Physical Properties and Behaviour of Commonly used Excipients to Stabilise Antigens, Adjuvants and Proteins in the Solid State." Thesis, University of Bradford, 2015. http://hdl.handle.net/10454/15943.
Повний текст джерелаАнотація:
This dissertation has focused on studying the effect of four glycine derivatives on the solid state properties of mannitol, glycine, and sucrose when freeze dried into blended mixtures. The primary goal was to assess their value for use in the stabilisation of vaccines in the solid state, by examining key physical and chemical characteristics, which have been documented to be beneficial to the stabilisation of biopharmaceutical formulations. The novel excipients; dimethyl glycine, and trimethyl glycine, were shown to retard the crystallisation and increase the overall glass transition temperature, of mannitol, when freeze dried as evidenced by DSC and Powder X-ray diffraction. Mannitol’s glass transition temperature increased from 100C to 12.650C and 13.610C when mixed with methyl-glycine and dimethyl glycine respectively. The glycine derivatives did not show the same effect on sucrose which remained amorphous regardless of the concentration of the other excipient. The different behaviour with the sucrose system was thought to be due to relatively high glass transition temperature of sucrose. Conversely glycine remained highly crystalline due it’s relatively low glass transition temperature. The novel excipient formulations were also assessed for their effect on the aggregation of the adjuvant aluminium hydroxide when freeze dried by Dynamic Light Scattering (DLS).The formulations containing the glycine derivatives all caused a decrease in the aggregation size of the adjuvant from ~26 μm, to 185 nm in the presence of methyl glycine. The effects of lysozyme and viral antigen on the adjuvants were also examined showing that the addition of the virus did not affect the size of the aggregates formed, however lysozyme showed significant decreases in the aggregates formed. Examination of the freezing method were also made showing that faster freezing rates produced smaller aggregates of the adjuvant. When investigating the rate at which the excipients lost water during secondary drying there was evidence of the formation of hydrates of glycine, trimethyl glycine, and mannitol has shown that the glycine derivatives have attributes which would be beneficial in stabilising vaccines in the solid state when freeze dried.
9
Huo, Hongguang. "Tailored cell attachment and cytotoxicity in PEG-based polysaccharide-derivatized hydrogels." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 117 p, 2007. http://proquest.umi.com/pqdlink?did=1253510481&Fmt=7&clientId=79356&RQT=309&VName=PQD.
Повний текст джерела
10
Bagga, Kishore Kumar. "Synthesis of hexamethylmelamine, polyethylene glycol and glucose derivatives for use in anti-cancer and sugar transport studies." Thesis, Aberystwyth University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301609.
Повний текст джерела
11
Kaniuga, Michael Brian. "Applicator Exposure to Glycol Derivatives and Total Volatile Organic Compounds during the Application of Spray Polyurethane Foam Insulation." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5427.
Повний текст джерелаАнотація:
There is currently high demand for new building materials which are considered "environmentally friendly" or "green" for both new construction and renovations. Spray polyurethane foam (SPUF) insulation has gained significant acceptance by both consumers and the construction industry due to its high R-value, which results into significant energy savings among other things. Despite its acceptance by consumers and the construction industry, consideration must be given to potential chemical exposures to applicators installing these products.
This study sought to determine, through quantitative experimentation, if there was a release of glycol derivatives including, diethylene glycol (DEG), ethylene glycol (EG), and propylene glycol (PEG), during the application of SPUF. In addition, total volatile organic Compounds (tVOCs) and various environmental parameters were also collected during this research.
This study utilized a two-component small-scale SPUF kit manufactured by the Dow Chemical Company, known as the FROTH-PAK™ kit. This specific kit is typically used by the construction industry to fill cavities, cracks, floor and wall penetrations, and expansion joints of buildings.
In order to determine the presence of these glycol derivatives, personal breathing zone samples were collected during the application of the SPUF during three application trials. Glycols derivatives were measured using active sampling techniques. Supplementary parameters including tVOCs, ambient and wet-bulb temperature, relative humidity, carbon monoxide, and carbon dioxide, were measured using direct-reading techniques. During this study several modifications were made to the work area and the air sampling methodology to assist in verifying the presence of the glycols and the conditions in which they may be present in the air during the application of SPUF insulation. All samples were sent to an accredited laboratory and were analyzed by the Nation Institute of Occupational Safety and Health Method 5523.
During this study, measurable amounts of diethylene glycol and propylene glycol were detected in two of the trials in which no ventilation in the work area was utilized. During one trial in which a work area ventilation system was utilized, none of the glycols were detected in the laboratory analysis above the limit of detection given the analytical method. Ethylene glycol was not detected in any of the samples submitted for analysis. The results for the tVOC measurements were inconclusive.
Based on the results of the air sampling, it is likely that exposure to diethylene glycol and propylene glycol may occur under certain conditions. However, due to the limited number of samples and the variation between the samples collected in this study, a generation rate or concentration buildup estimate for comparison of the OELs was not conducted. These conditions include the quantity of ventilation used during application, the application duration, and proper operation of the SPUF application equipment. Based on the results, there is evidence that additional research may be needed in this area.
12
Tuzcu, Gozde. "2-acrylamido-2-methyl-1-propanesulfonic Acid -methacrylic Acid Copolymer And Its Polyethylene Glycol Methyl Ether Derivatives As Superplasticizers In Concrete." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609380/index.pdf.
Повний текст джерелаАнотація:
Polymers in concrete have received considerable attention over the past 30 years. Superplasticizers are one of the admixtures which have polymeric structure. In this study, polycarboxylate type slump-releasing dispersant, which is a copolymer of 2-acrylamido-2-methyl-1-propanesulfonic acid
(AMPS) and methacrylic acid (MAA), was synthesized in different feed compositions. The synthesis procedure of this copolymer was retrieved from literature. The derivatives of this water-soluble copolymer (AMPS-MAA) were synthesized by a macromonomer which was synthesized by the esterification of poly(ethylene glycol) methyl ether (PEG) with MAA (PEGMA) and then copolymerizing this macromonomer with AMPS monomer, the resulting copolymer is AMPS-PEGMA. In order to study the methyl group effect on fluidity, the other type of macromonomer (PEGA), composed of PEG and
acrylic acid (AA), was synthesized and copolymerized with AMPS monomer, giving AMPS-PEGA. The structures of synthesized polymers were verified by NMR and FT-IR analysis. The slump-releasing effect of the synthesized
copolymers was studied in terms of reaction pH, composition, molecular weight, amount of PEG side chains, and molecular weight of PEG side chains. The AMPS-MAA copolymer with 40% AMPS content was the most effective in promoting the fluidity of cement pastes. In scope of reaction pH, the AMPS-MAA copolymer, synthesized at a pH of 11, gave the most
effective result on fluidity of the cement pastes. In copolymers of PEG acrylate macromonomers and AMPS monomers, copolymers with 5% PEG acrylate content showed the highest fluidity both in copolymers of PEGA and PEGMA. In copolymers with PEG side chains, the 15% AMPS-PEGA
copolymer synthesized at pH of 6 gave the most effective result on fluidity of cement pastes. In the study of mechanical properties of the mortar samples
prepared by the copolymers selected, AMPS-PEGA copolymer with 25% PEG content showed the highest flexural strength, and AMPS-MAA copolymer with 60% AMPS content and a reaction pH of 11 gave the highest compressive strength. In this study, zeta potential measurements were also performed to analyze the fluidity behavior of the copolymers.
13
Griveau, Lucie. "Emulsion polymerization in the presence of reactive PEG-based hydrophilic chains for the design of latex particles promoting interactions with cellulose derivatives." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1329/document.
Повний текст джерелаАнотація:
Dans cette thèse, des particules de polymère fonctionnalisées en surface avec des groupes poly (éthylène glycol) (PEG) ont été synthétisées pour favoriser leur interaction avec les dérivés cellulosique via liaisons hydrogène intermoléculaires. Deux voies de synthèse ont été proposées pour obtenir ses composites cellulose/latex.La première voie est basée sur l'auto-assemblage induit par polymérisation (PISA) pour former des nanoparticules fonctionnalisées avant leur adsorption sur un substrat cellulosique. La PISA tire profit de la formation de copolymères blocs amphiphiles dans l'eau en combinant la polymérisation en émulsion avec les techniques de polymérisation radicalaire contrôlées (RDRP). Ces dernières sont utilisées pour synthétiser des polymères hydrophiles agissant à la fois comme précurseur pour la polymerization en émulsion d'un monomère hydrophobe, et comme stabilisant des particules de latex obtenues. Deux techniques de RDRP ont été étudiées : les polymérisations RAFT et SET-LRP. Des polymères hydrophiles à base de PEG de faible masse molaire ont été synthétisés en utilisant ses deux techniques qui sont ensuite utilisés pour la polymérisation d'un bloc hydrophobe dans l'eau. Le transfert de l'agent de contrôle au site de la polymérisation était difficile en utilisant la SET-LRP en émulsion, conduisant à la formation de larges particules. En utilisant la RAFT en émulsion, des particules nanométriques ont été obtenues, avec un changement morphologique observé en fonction de la taille du segment hydrophobe, puis adsorbées sur des nanofibrilles de cellulose (CNF).La seconde voie utilise la polymérisation en émulsion classique réalisée en présence de nanocristaux de cellulose (CNC) conduisant à une stabilisation Pickering des particules de polymère. L'interaction cellulose/particule est assurée grâce à l'ajout d’un comonomère à type PEG. Une organisation a été visualisé dans laquelle plusieurs particules de polymère recouvrent chaque CNCIn this thesis, polymer particles surface-functionalized with poly(ethylene glycol) (PEG) groups were synthesized to promote their interaction with cellulose derivatives via intermolecular hydrogen bond. Two synthetic routes were proposed to obtain such cellulose/latex composites.The first route was based on the polymerization-induced self-assembly (PISA) to form functionalized polymer nanoparticles prior to adsorption onto cellulosic substrate. PISA takes advantage of the formation of amphiphilic block copolymers in water by combining emulsion polymerization with reversible-deactivation radical polymerization (RDRP) techniques. The latter were used to synthesize well-controlled hydrophilic polymer chains, acting as both precursor for the emulsion polymerization of a hydrophobic monomer, and stabilizer of the final latex particles. Two RDRP techniques were investigated: reversible addition-fragmentation chain transfer (RAFT), and single electron transfer-living radical polymerization (SET-LRP). Low molar mass PEG-based hydrophilic polymers have been synthesized using both techniques, used for the polymerization of a hydrophobic block in water. The transfer of controlling agent at the locus of the polymerization was challenging for SET-LRP in emulsion conditions leading to surfactant-free large particles. Nanometric latex particles were obtained via RAFT-mediated emulsion polymerization, with morphology change from sphere to fibers observed depending on the size of the hydrophobic segment, which were then able to be adsorbed onto cellulose nanofibrils (CNFs).The second route used conventional emulsion polymerization performed directly in presence of cellulose nanocrystals (CNCs) leading to Pickering-type stabilization of the polymer particles. Cellulose/particle interaction was provided thanks to the addition of PEG-based comonomer. Original organization emerged where CNCs were covered by several polymer particles
14
Zheng, Yuan. "Chemoenzymatic Synthesis of UDP-GlcNAc and UDP-GalNAc Derivatives for Chemoenzymatic Labeling." 2017. http://scholarworks.gsu.edu/chemistry_theses/97.
Повний текст джерелаАнотація:
Glycans are macromolecules that contain several classes. Glycans can play an important role in biological activities. Studying the cell surface glycans can provide a very powerful way to understand the fundamental process. Also it could help to regulate expected cell response. Thus it is very necessary to have a method to detect cell- surface glycans efficiently.
An efficient method for glycan detection is necessary. Metabolic glycan labeling and chemoenzymatic glycan labeling are most commonly used. Chemoenzymatic glycan labeling is a rapid and sensitive method which also has high specificity. This method can be applied in both vitro and vivo. However the availability of unnatural sugar nucleotides functioned by bioorthogonal groups is the main limitation for chemoenzymatic labeling.
In this thesis, UDP-GlcNAc and UDP-GalNAc derivatives were prepared for further chemoenzymatic labeling by using chemoenzymatic synthesis method.
15
Wilkinson, Ian. "Tolerogenic monomethoxypolyethylene glycol derivatives of xenogeneic monoclonal immunoglobulins." 1989. http://hdl.handle.net/1993/16916.
Повний текст джерела
16
Ching-Hung, Chen, and 陳敬泓. "Preparation and Surface Activity of Propylene Glycol Glycoside Derivatives." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/35076186314222588927.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
高分子工程系
91
In this study, propylene glycol glycoside composition was prepared by acid-catalyzed acetalization of glucose with propylene glycol. Then, alkylglycidyl ether with a long alkyl chains having from 8 to 16 carbon atoms were reacted with propylene glycol glycoside to synthesize a series of propylene glycol glycoside derivatives nonionic surfactants. The structure of propylene glycol glycoside derivatives were characterized by FT-IR、1H-NMR and elemental analysis. From the results of the experiments, these propylene glycol glycoside derivatives can display excellent surface-active properties including reducing surface tension, better pH buffer capacity, increasing conductance and promoting wetting power, etc. Increasing alkyl chain length decreases to the critical micelle concentration (CMC). This tendency can be seen usually in the case of polyoxyethylene type nonionic surfactants. But, these propylene glycol glycoside derivatives containing a 14 to 16 carbon chain could not be measured due to their lower solubilities in water. An octyl, decyl, or dodecyl propylene glycol glycoside derivatives occupies about 50 Å2 at the air/water interface. It was found that all propylene glycol glycoside derivatives tested in this study were biodegraded over 50% in five days. These propylene glycol glycoside derivatives also have been found to exhibit a good scouring and dispersing effects used in cotton scouring.
17
Ribeiro, Morais Goreti, Rudi S. Oliveira, and Robert A. Falconer. "Selective synthesis of Neu5Ac2en and its oxazoline derivative using BF3.Et2O." 2009. http://hdl.handle.net/10454/4616.
Повний текст джерелаАнотація:
NoApplication of the Lewis acid BF3·Et2O to the selective synthesis of 5-acetamido-2,6-anhydro-3,5-dideoxy-d-glycero-d-galacto-non-2-enonic acid (Neu5Ac2en) and the related oxazoline, methyl 7,8,9-tri-O-acetyl-2,3,4,5-tetradeoxy-2,3-didehydro-2,3-trideoxy-4',5'-dihydro-2'-methyloxazolo[5,4-d]- d-glycero-d-talo-non-2-enonate is described.
18
Wu, Hsu-Hsuan, and 吳旭軒. "(1) Design and synthesis of (-)-Acaterin derivatives 、(2) Stereoselective Glycosylation of endo-Glycals." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/58041727766066058266.
Повний текст джерелаАнотація:
碩士中國醫藥大學
藥物化學研究所碩士班
97
The intermediate compounds was synthesized by Baylis-Hillman reaction to couple acetaldehyde and the compound 13. We also used the starting compound 27 followed by reduction and Wittig rection to affored the intermediate compounds (E)-46, (Z)-46. The further works will be finished by Mitsunobu and Grubbs catalysis reaction to give to major compound 23. A new method for synthesis of ??-2-deoxyglycosides from hex-1-en-3-uloses is reported, hex-1-en-3-uloses were shown to be efficient glycosyl donors by using catalyst amount of AlCl3 in microwave-assisted glycosylation. In these reaction ??-glycosyl additions occurred with highly stereoselectivity (??:??=10:1). Fully protected endo-glucals are directly converted into compound 104, 105 by 1eq PhI(OH)OTs, followind addition amino in methanol at room temperature for 30 mins to affored the ??-enamino ketones.This sequestration reaction occurs in two steps which were studied separately and in a one-pot rection.
19
Chin, Yang Chen, and 楊振欽. "Study on High-Temperature Alcoholysis of Isocyanate Derivatives Using n-Butanol and Ethylene Glycol." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/89172434703332167557.
Повний текст джерелаАнотація:
碩士國立中興大學
化學工程學系
89
Because of increasing quantity of PU wastes internationally coupling with growing environmental concern for the TDI production tars, current burning and burial methods of dealing with these problems are clearly not acceptable. Since these materials are mostly isocyanate derivatives containing urethane, urea and carbodiimde functionality, this research attempts to find a common chemical solution of dealing with these materials. Our research has been using alcoholysis of PU materials with n-butanol and ethylene glycol to digest the wastes and converted them into low molecular weight alcohols and amines for further uses. In order to demonstrate the feasibility of this approach, our experiment started with alcholysis of model derivatives of phenyl isocyanate that include urethane, urea, dimer, trimer, and others with n-butanol, and established that most of isocyanate derivatives could be converted at 240℃ into n-butyl carbamate and aniline in good yield. In addition, by treating the same model derivatives of phenyl isocyanate with ethylene glycol, we uncovered that the alcoholysis all goes through ethylene carbonate as intermediate which reacts further with aniline to form 2-anilinoethanol as the EG alcholysis product. Finally, we are able to demonstrate that both alcoholysis methods could digest polyurethanes, such as flexible and rigid foams, or polycarbonate into low molecular weight alcohols and amines of definite structures. It is hoping that further works will carry on to find the use of these low molecular weight alcohols and amines as PU raw materials.
20
CHIU, WEI-JEN, and 邱唯禎. "The Determination of Bile Acids And Glycol-Derivatives in Biological Samples With LC-MS/MS." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/48677052683199350216.
Повний текст джерелаАнотація:
碩士靜宜大學
應用化學系
104
Cholesterol is the major bile acid metabolite. Therefor bile acid concentration abnormality will lead to different types of disease in the human body. For example primary biliary cirrhosis, gallstones, breast cancer, colorectal cancer, etc. Bile acid is also used to treat diseases. Chenodexycholic acid and ursodeoxycholic acid is used to replace the patient surgical treatment of gallstones. In our study, we used liquid chromatography tandem mass spectrometer (LC-MS) to detect trace amounts of bile acids including cholic acid (CA), deoxycholic acid (DCA), lithcholic acid (LCA), ursodeoxycholic acid (UDCA), chenodexycholic acid (CDCA), hyodeoxycholic acid (HDCA) and their glycine-conjugated form in livers. We combined liquid-liquid extraction, solid phase extraction to save solvent and matrix interferences and multiple reaction monitoring mode (MRM) in mass spectrometer to detect product ion signal cleaved from precursor ions can successful qualitative and quantitative bile acids content in biological samples. Limit of detection 0.53-5.53 ng/mL (S/N=3). Recoveries of bile acids were more than 88% for real samples. In this work, the extraction method is simple and small amount of organic solvents can quickly detect bile acids in biological samples.
21
Yang, Lun-Cheng, and 楊淪証. "Synthesis of Diethylene Glycol Functionalized Diketopyrrolopyrrole Derivatives Based Side-Chain Conjugated Polymers For Photovoltaic Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/41637032846014352636.
Повний текст джерелаАнотація:
碩士國立中興大學
化學工程學系所
103
We synthesized four two-dimensional (2-D) conjugated polymers, including diethylene glycol functionalized diketopyrrolopyrrole derivatives PEGA13, PEGA12, PEGA11, and 2-ethylhexyl functionalized diketopyrrolopyrrole derivative PEHA13 featuring thionphene as π-conjugation bridge in the polymer backbones and appending conjugated triphenylamine/thiophene (TPATh) moieties on the side chains. Excellent thermal stability was observed for PEGA13, PEGA12, PEGA11, and PEHA13. Incorporating the thiophene into the polymer backbones and appending TPATh units indused high degrees of intramolecular charge transfer within the conjugated framework of the polymers, thereby resulting in low band gap energies and red-shifting of the maximal UV-Vis absorption wavelengths. The PEGA13, PEGA12, PEGA11, and PEHA13 show two absorption bands in the range of 350-900 nm, corresponding to the band gaps of 1.42, 1.38, 1.38, 1.46 eV, respectively. The performance of the OSCs was modified significantly with varied of PEGA13 (or PEHA13)/PC61BM (or PC71BM) weigh ratio. A power conversion efficiency of 3.1 %, a short-circuit current density of 13.2 mA/cm2, an open-circuit voltage of 0.64 V, a fill factor of 0.37, and a hole mobility of 3.32×10-5 were observed for OSCs based on the active layer of PEGA13/PC71BM (1:2, w/w).
22
Kao, Yu-Hsuan, and 高玉軒. "Synthesis and Characteristics of Polyethylene Glycol Copolymer Using Triphenylamine and Carbazole Derivatives for Perovskite Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/53377727322277315643.
Повний текст джерелаАнотація:
碩士國立臺灣大學
化學工程學研究所
103
In this study, the diol derivatives of Triphenylamine(TPA) and Carbazole were successfully synthesized and polymerized into polyurethane, then co-polymerized with Polyethylene glycol of various average molecular weights to form copolymers. Triphenylamine molecule is widely used in hole transporting material due to its excellent hole-transporting ability; Carbazole molecule has good hole-transporting ability and relatively higher Highest occupied molecular orbital (HOMO); Ethylene glycol can increase the ion transporting ability. To use these copolymers as hole transport materials in perovskite solar cells is expected to lead to the increase of photocurrent, open-circuit voltage, fill factor, and the power conversion efficiency. To make sure the synthesized copolymers can go through all the manufacturing process of perovskite solar cells, Differential scanning calorimetry (DSC) is used to test the glass transition temperature of them. UV/Visible spectroscopy (UV-vis) helps us know their light-harvesting ability. We can also compare the solution forms with film patterns to analyze the packing and film-forming ability. Cyclic voltammetry (CV) tells us the oxidation potential and the energy level of these copolymers, which can help us check that the material lies on the correct energy level. For the part of perovskite solar cell device, the copolymer of TPA is first mixed into the active layer. Next, the Spiro-OMeTAD in hole-transport layer is replaced by the PU copolymers. The effect of different average molecular weight of PEGs is then to be discussed. When the average molecular weight of PEG comes to 200, we get the best power conversion efficiency. Finally, the highest power conversion efficiency reaches 9.23 % with active layer blended with PU and Carbazole PU as the hole-transporting material, which is 27.1 % higher than the standard perovskite solar cell.
23
Chen, Meng-Chun, and 陳孟群. "Synthesis of Glyco-Arylboronate Derivative on Gold Nanoprobe for Visual Detection of H2O2." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5810007%22.&searchmode=basic.
Повний текст джерелаАнотація:
碩士國立中興大學
生醫工程研究所
107
The purpose of this study is to develop a colorimetric assay to detect hydrogen peroxide (H2O2) by using arylbronate (AB) derivative functionalized gold nanoparticles (AuNP). H2O2 is one of the important reactive oxygen species (ROS) in the living system. The aberrant production or accumulation of H2O2 is highly related to serious human disease including cancers, neurodegenerative disorders and cardiovascular. The unique optical property of AuNP is applied and designed as a detection probe. The aggregation characteristic of AuNP could be directly observed its color change by the naked eye. In this study, we designed the Mannoside-Boronate-Sulfide (MBS) ligand contains an arylboronate (AB), a mannoside and the thiol group. The thiol group can form a covalent bond with surface of AuNP to obtain MBS@AuNP. The AB structure can react with H2O2 and then inserts an oxygen atom between B-H bond, which consequently triggers the intramolecular electron rearrangement to cleavage its covalent bond. The mannoside moiety can recognize concanavalin A (Con A), which is a lectin with four carbohydrate recognition sites and can specifically recognize non-reducing end α-D-mannoside or α-D-glucoside structure. This study also discusses the synthetic protocol optimization to yield stable MBS@AuNP. We found that in the final step of preparation process to add PEG33-SH ligand can stabilize MBS@AuNP. When MBS@AuNP incubated with Con A, Con A can recognize multiple mannosides on the surface of MBS@AuNP, subsequently MBS@AuNP aggregated. The red color MBS@AuNP solution converted to blue. The phenomena could be observed by a naked-eye within a minute. The UV absorption wavelength of MBS@AuNP had a significant red-shifted from 527 to 550 nm. Besides, a polyethylene glycol-modified on AuNPs (PEG33@AuNP) was designed as a negative control. The bovine serum albumin (BSA) was used as a negative control protein . Nuclear magnetic resonance (NMR) technique was applied to monitor the reaction condition of MBS ligand with H2O2. We found that the reaction temperature at 37 ℃ could provide sufficient energy for MBS to react with H2O2 and then trigger the intramolecular electronic rearrangement. Finally, MBS@AuNP was used to detect various concentration of H2O2 (0、3、6、12.5、25、50、100、200、400 to 800 μM) at 37 ℃. In this study, the MBS@AuNP detection limit for H2O2 was 6 μM by using UV-Vis spectra. In order to quantify MBS@AuNP and H2O2 of the reaction process, Con A was modified on the surface of QCM. The gold chip was self-assembled by using 11-mercaptoundecanoic acid (MUA). Carboxyl group on the surface of gold chips was activated by 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) and then coupled with the amino group of Con A. When MBS@AuNP bound with Con A, the QCM frequency decreased due to the weight change on the gold chips. When H2O2 was added, the MBS@AuNP was disassociated from the chip surface, and therefore the frequency signal in QCM would increase. However, an effective Con A modification method on the surface of QCM chip is a critical step for current study. More experiment is needed to confirm the data.
24
Lin, Zi-Ping, та 林子平. "Synthesis of α-2-Deoxy-ulosides and β-Enaminals Derivatives by Michael Addition of Conjugated endo-Glycals". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90822838313409505526.
Повний текст джерелаАнотація:
博士中國醫藥大學
藥物化學研究所博士班
101
α-2-Deoxyulosides were synthesized in moderate to good yields by Michael addition of various O-nucleophiles to hex-1-en-3-ones in the presence of NaOH. These glycosyl additions were complete in 30 min at room temperature with high α-stereoselectivity in 53–92% yield. In addition, high α-stereoselectivity was also observed when S-nucleophiles were examined at 0 oC for 90 min. β-Enaminals were successfully synthesized in good to excellent yields by the reaction of C-2-formylglycals with primary amines. Subsequent reaction with NaBH4 in HOAc led to unexpected reductive cleavage of allyl ether, i.e. the hydrodealkoxylation took place to produce the corresponding 3-deoxy-β-enaminals. In contrast, the reaction of β-enaminals with Zn/HOAc performed H4-elimination to afford a diene product. The result was attributed to the formation of a common eneiminium ion intermediate, and the different reduction reactivity.
25
Sie, Cheng-Yan, та 謝承諺. "Behaviors of Ascorbic Acid Derivative/D-α-Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS) Mixtures: Multitechnique Investigation". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/64156997920748818550.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
化學工程與材料工程系碩士班
101
In this study, we found that compound A can form nanoparticles by a modified ethanol injection method for the first time, In order to improve the stability of compound A nanoparticles, D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) was added into compound A nanoparticles. In addition, the effects of polyethylene glycol chain (PEG1000) on compound A dispertions were investigated by compared with mixed A/α-Tocopherol (VE) nanoparticles. Physicochemical characteristics of mixed A/TPGS and A/VE nanoparticles were investigated by multi-techniques including dynamic light scattering (DLS), transmission electron microscope (TEM), fluorescence spectrometer and differential scanning calorimetry (DSC). High performance liquid chromatography (HPLC) was used to study the chemical stability of mixed A/TPGS dispersionss in different concentrations of dithiothreitol (DTT). Transdermal absorption studies of A/TPGS nanoparticles across the rat skin were investigated by using Franz diffusion cells. Furthermore, behavior of mixed A/TPGS and A/VE monolayers at the air/water interface were measured at 24 ℃ by Langmuir trough system combined with fluorescence microscopy. Adding TPGS into compound A nanoparticles decreased average particle size among the A/TPGS systems, and mixed A/TPGS 6:4 dispersions showed the smallest average particle size. Mixed A/TPGS (9.9:0.1, mol ratio) dispersionss exhibited better storage stability than pure compound A dispersions. Main phase transition temperature of A dispersionss was found at 59.4 ℃. The phase transition temperature remained constant, and the enthalpy of the observable gel to liquid-crystalline phase transition decreased with increasing XTPGS or XVE, and the phase change enthalpy was eliminated at XTPGS = 0.5 or XVE = 0.1. By Comparing results of mixed A/TPGS with A/VE systems at the same molar ratio, PEG-chains was found to enhance the intermolecular interactions. At room temperature (compound A is under gel state), the incorporation of TPGS or VE into compound A membrane reduced the mobility in hydrocarbon chain region, and the presence of TPGS generally increased the molecular mobility of the interfacial region of the membrane. This indicated that PEG-chain may soften compound A membrane structure. The most chemical stability was found as the mixed A/TPGS (9:1) dispersions in 0.01M concentration of DTT. Adding TPGS can improve compound A dispersions permeability, and mixed A/TPGS (9/1) dispersions exhibited better transdermal efficacy absorption than pure compound A dispersionss. Monolayer results showed that mixed A/TPGS monolayers were more expanded than mixed A/VE monolayers, possibly resulting from PEG-chains steric barrier. Excess area results showed that the mixed A/TPGS monolayers were negative deviation and mixed A/VE monolayers were positive deviation at low surface pressure, implying PEG-chain makes intermolecular arrangement tighter. In addition, the mixed A/TPGS and A/VE monolayers were positive deviation at high surface pressure, which maybe caused by steric repulsive of neighboring PEG-chains. Excess Gibbs free energy and the free Gibbs energy results showed that mixed A/TPGS monolayer molecules were more miscible and thermodynamic stable than mixed A/VE monolayer. Fluorescence imaging results showed that compound A molecules aggregated into dendritic domain, indicating that the impact of line tension was less than the dipole repulsion. At constant surface pressure, adding TPGS into compound A domain make compound A Domain become smaller and uniformly distributed, indicating TPGS will make intermolecular more expaned. On the other hand, adding VE, part of the domain become large, and turn into circular shape by the dendrimers. This indicates that steric repulsion of PEG-chain will make intermolecular no cohesive interaction in mixed monolayers.
26
Lin, Pai-Fu, та 林柏甫. "Investigation of mechanical and rheological properties for α-cyclodextrins (α-CDs) /poly (ethylene glycol) PEG polyrotaxanes and its derivatives". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/du2x8x.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
有機高分子研究所
96
This study focused on the synthesizing of a novel supramolecular structure “polypseudorotaxanes/polyrotaxanes.” The molecular structure was based on α-cyclodextrins (α-CDs)/poly(ethylene glycol) PEG polyrotaxanes. There was no apparent intramolecular bonding in between α-CDs and PEG, only non-covalent bonding such as hydrogen bonding and Van der Waals force were extant. Therefore, crosslink point formed between two α-CDs and it could slide along the PEG chain, thus, this soft and hard chain allows the forming of an elastic material. In addition, polyrotaxane derivatives were obtained by the polyrotaxane modification reactions such as acetylation and hydroxypropylation, and mechanical properties (stress-strain, creep and recovery & shrink) were investigated with DMA. Furthermore discovered when hydroxyl group were substituted, the elasticity of material increased due to the decreasing of hydrogen bonding. Moreover, crosslinked the polyroytaxanes with a crosslinking agent (DVS) and dynamic test was investigated with SR5.
27
Wang, Fu-Yu, and 汪富瑜. "Synthesis and Characterization of Dendritic-like Polypropylene Glycol Derivatives Contained Ethyleneimine Groups and Their Use as Protectors for Copper Nanoparticle Preparation." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/ay8na4.
Повний текст джерелаАнотація:
碩士國立成功大學
化學工程學系碩博士班
90
Abstract In this study, ethyleneimine (EI) group was introduced into polypropylenediamine with different molecular weight by a simple in-situ reaction with 2-chloroethylamine hydrochloride. The EI number (N) of these dendritic-like polymers was determined by 1H-NMR, and the percentages of primary, secondary, and tertiary amines were estimated by potentiometric titration. Then, the measurements of surface tension and the ratio (I1/I3) of intensities of the fluorescence of pyrene for polymer solutions were used to interpret their behaviors in water. The chelating ability of these polymers towards copper ion (Cu2+) has been examined by UV/Vis spectroscopy. The copper nanoparticles protected by these dendritic-like polymers were characterized by TEM images, and the effects of concentration, EI number of polymer, and amounts of reducing agent (NaBH4) on the prepared copper nanoparticles were investigated. From the experiment results of surface tension and I1/I3, it is clear that the polymer chains in the aqueous solution transfer to the air/water interface before forming polymer aggregates. The degree for these polymers to reduce the surface tension in aqueous solution is D4E4＞D4E8＞D2E4. The eases for these polymers to form aggregates in aqueous solution is D4E8＞D4E4＞D2E4. The chelating ability of polymers towards copper ion (Cu2+) is D4E8＞D4E4≒D2E4. The trend of the average size of copper nanoparticle in the presence of these polymers is D4E8＜D4E4＜D2E4. Also, the increasing polymer concentration decreases the size of copper nanoparticles.
28
KUO, YUAN-TSUNG, and 郭原宗. "Kinetic Studies of Type II Photoinitiator Photopolymerization Based on 2-Chloro-hexaarylbimmidazole (o-Cl-HABI)/N-Phenyl glycine (NPG) and Its Derivatives." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/27mms6.
Повний текст джерелаАнотація:
碩士國立高雄應用科技大學
化學工程與材料工程系博碩士班
106
Type II photoinitiator systems are widely used in photocuring processes due to their low cost, faster photospeed which applied in many industrial applications such as photoresist dry film and imaging. One of the typical Type II photo-initiator package based on o-Cl-HABI (hydrogen acceptor) and NPG (hydrogen donor) systems (where o-Cl-HABI is a 2-chlorohexaaryl biimidazole, NPG is an N-phenyl glycine) was investigated in this study. The photocuring behavior for different weight ratios of o-Cl-HABI and NPG was studied through FT-IR, gel-fraction, electron spin resonance (ESR) and photoluminescence (PL) methodologies. As the amount of NPG increased from 0.05 wt% to 0.1and 0.25 wt%, the faster curing speed was achieved. However, the curvature photo-reactivity phenomenon was observed as the amount of o-Cl-HABI at 0.5, 1 and 2 wt%, respectively. In this study, the air and nitrogen atmospheres effect are conducted. Since NPG is an important factor on the photocuring reactivity, the structural modification of NPG is also performed for comparison. The p-OCH3, -Cl, -NO2 NPG derivatives were synthesized accordingly. These structures were identified by 1H-NMR and mass spectrometry. The NPG derivatives exhibited melting temperatures of 146-238 oC that was higher than the reference NPG (127 oC). The NPGs also displayed good solubility in Acetone, THF and DMF. In addition, the molar extinction coefficients of NPG, OCH3-NPG, Cl-NPG and NO2-NPG were 4.34×104 M-1cm-1, 2.36×104 M-1cm-1, 2.08×104 M-1cm-1, 1.13×103 M-1cm-1, respectively. In addition, the HOMO, LUMO levels and their corresponding ΔGET values were calculated to correlate with the photoreactivity. The double bond conversion was final tested through the gel fraction method under the same weight ratios (o-Cl-HABI/NPG = 2:0.05 wt%). The order of conversion rate is NPG > OCH3 -NPG > Cl-NPG > NO2-NPG that is consisted with ΔGET values mentioned above.