Dissertations / Theses on the topic 'Tetramic Acid'
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1
Bates, Andrew D. "New reactions in tetramic acid synthesis." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252629.
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Pillainayagam, Terence Anthony. "New methods in tetramic acid synthesis." Thesis, Loughborough University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416685.
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Lewis, Ian. "Studies in the synthesis of polyene tetramic acid antibiotics." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/12412.
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Moore, M. Caragh. "Biosynthetic studies on tenellin and aminoisobutyrate metabolism in Streptomyces sp." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4837/.
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This thesis is divided into two parts. Part 1 covers the biosynthesis of the fungal metabolite tenellin, and Part 2 the metabolism of β-aminoisobutyrate m Streptomyces sp. Tenellin is a yellow pigment of the fungus Beamaria bassiana. It is of mixed biosynthetic origin, being derived from a polyketide moiety and the amino acid L-phenylalanine. The timing of the C-methylations of the polyketide chain is discussed in Chapter 2, which describes attempts to incorporate deuterium labelled partially assembled putative intermediates into the polyketide. The biosynthesis of the pyridone ring of tenellin requkes the condensation of the polyketide moiety with a rearranged phenylpropanoid unit derived from phenylalanine. The nature of this intriguing intramolecular rearrangement is discussed in Chapters 3 and 4. A phenylalanine derived tetramic acid, proposed as an intermediate in the biosynthesis, has been synthesised, and used in biosynthetic investigations. The results of these investigations and the subsequent identification of tyrosine as a closer precursor to tenellin argue against its intermediacy. The failure of [2-(^13)C(^2)H(^15)N]-phenylalanine to become incorporated intact suggests a transamination process for phenylalanine / tyrosine prior to incorporation. Preliminary investigations suggest para-hydroxy phenyllactate may be die substrate for the rearranging enzyme and a more direct precursor to tenellin. β-Aminoisobutyrate, the end product of reductive thymine catabolism, contributes to both the propionate and butyrate pools in Streptomyces sp. The pathway of incorporation into the isobutyrate / butyrate pool has been investigated, and confirmed to be the reverse of that known to occur in L-valine metabolism. A mutant strain of Streptomyces avemitilis, unable to produce isobutyrate, was used due to low level incorporations into the branched-chain fatty acids. This work was carried out in collaboration with Dr. Hamish McArthur, Pfizer Central Research Division, Groton, USA, and Dr. Kevin Reynolds, Department of Pharmaceutical Science, University of Maryland.
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Fischer, Joshua. "HIV-1 Integrase Inhibitors: A Formal Total Synthesis of Lithospermic Acid And Synthetic Studies Towards Integramycin." Thesis, The University of Sydney, 2007. http://hdl.handle.net/2123/2397.
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This thesis describes synthetic studies towards the HIV-1 integrase inhibitory natural products lithospermic acid and integramycin, resulting in a formal total synthesis of the former. A modular, flexible and convergent synthetic strategy to lithospermic acid was devised. In this approach, a Sonogashira coupling was used to unite the C1–C7 and C20–C27 fragments that were subsequently manipulated to then participate in the key step of the synthesis, a palladium-mediated carbonylative annulation. Reduction of the benzofuran nucleus with magnesium in methanol then provided the desired dihydrobenzofuran core of lithospermic acid. Various protecting group strategies were investigated to complete this sequence in an efficient manner. Further synthetic manipulations afforded the complete C1–C9/C19–C27 fragment, which was united with the C10–C18 fragment to deliver the entire carbon skeleton of lithospermic acid. A two step deprotection sequence was undertaken, however, complications with the final deprotective step prevented definitive proof that the total synthesis of lithospermic acid had been achieved. An alternate protecting group strategy was sought, and a formal total synthesis of lithospermic acid was achieved by intercepting an advanced intermediate from a previous total synthesis. Several strategies for the enantioselective synthesis of the dihydrobenzofuran core of lithospermic acid were evaluated, however, none proved successful. A synthetic route towards the tetramic acid subunit of integramycin was also investigated. 3- Methoxymaleimide was constructed using known chemistry, and the regioselective reduction of this ring system was developed. Attempts to further functionalise this ring system were thwarted by difficulties associated with handling. The scope of the regioselective reduction was investigated on an array of N- substituted methoxymaleimides with the procedure found to be generally high yielding and highly regioselective.
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Fischer, Joshua. "HIV-1 Integrase Inhibitors: A Formal Total Synthesis of Lithospermic Acid And Synthetic Studies Towards Integramycin." University of Sydney, 2007. http://hdl.handle.net/2123/2397.
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Doctor of Philosophy (PhD)This thesis describes synthetic studies towards the HIV-1 integrase inhibitory natural products lithospermic acid and integramycin, resulting in a formal total synthesis of the former. A modular, flexible and convergent synthetic strategy to lithospermic acid was devised. In this approach, a Sonogashira coupling was used to unite the C1–C7 and C20–C27 fragments that were subsequently manipulated to then participate in the key step of the synthesis, a palladium-mediated carbonylative annulation. Reduction of the benzofuran nucleus with magnesium in methanol then provided the desired dihydrobenzofuran core of lithospermic acid. Various protecting group strategies were investigated to complete this sequence in an efficient manner. Further synthetic manipulations afforded the complete C1–C9/C19–C27 fragment, which was united with the C10–C18 fragment to deliver the entire carbon skeleton of lithospermic acid. A two step deprotection sequence was undertaken, however, complications with the final deprotective step prevented definitive proof that the total synthesis of lithospermic acid had been achieved. An alternate protecting group strategy was sought, and a formal total synthesis of lithospermic acid was achieved by intercepting an advanced intermediate from a previous total synthesis. Several strategies for the enantioselective synthesis of the dihydrobenzofuran core of lithospermic acid were evaluated, however, none proved successful. A synthetic route towards the tetramic acid subunit of integramycin was also investigated. 3- Methoxymaleimide was constructed using known chemistry, and the regioselective reduction of this ring system was developed. Attempts to further functionalise this ring system were thwarted by difficulties associated with handling. The scope of the regioselective reduction was investigated on an array of N- substituted methoxymaleimides with the procedure found to be generally high yielding and highly regioselective.
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Sagiraju, Sarada. "Synthesis and Spectroscopic Study of Anticancer agent A-007 Prodrugs and Progress Towards the Synthesis of Tetramic acid Antibiotics." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/900.
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4, 4'-Dihydroxybenzophenone-2, 4-dinitrophenylhydrazone (A-007) has recently completed a phase-I clinical trial, and objective responses were seen in advanced breast cancer, lung cancer, ovarian cancer, melanoma, skin cancer and non-Hodgkin's lymphoma. Despite the promising results in the clinical trials, the major disadvantage to using A-007 as a broad-scale therapeutic is its poor water solubility. To make use of this promising anticancer drug either orally or intravenously, the short-term obstacle must be to overcome the limited solubility of A-007 in water. There are several approaches to overcome this obstacle. The first approach is to make hydrolysable prodrugs of A-007. The second approach is to make an A-007 complex with a water soluble host, such as cyclodextrin. We used a combination of these two previously described methods, i.e. transforming A-007 into a more water soluble prodrugs and then further increasing the prodrug water solubility by making their cyclodextrin inclusion complexes. Our syntheses and spectroscopic explorations of A-007 prodrugs are presented in this dissertation. Tetramic acid (2, 4 pyrrolidine-2, 4-dione ring system) containing compounds have been found to display a remarkable diversity of biological activities and have attracted the interest of medicinal and synthetic chemists. Magnesidin (1-acetyl-3-octanoyl-5-ethylidene tetramic acid) has strong antimicrobial activity against bacteria that cause gingivitis and dental plaque. Current efforts toward the synthesis of Magnesidin are discussed along with the plans for the completion of synthesis.
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Healy, Alan R. "Development of novel modulators of protein-protein interactions associated with cancer." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6316.
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An understanding of the underlying mechanisms by which proteins engage and communicate within the complex cellular environment is critical to the elucidation of the molecular basis of disease states and the development of safer, more efficacious drug therapies. Diverse cellular functions, including replication, transcription, cell growth and intracellular signal transduction, are governed by extensive networks of protein-protein interactions (PPIs). Disruption of the finely-tuned cellular networks due to the formation of aberrant or unregulated PPIs is implicated in the development and progression of cancer. As a result, over the last decade, PPI modulation has developed as an attractive molecular target for novel cancer therapies and as a powerful research tool in chemical biology to provide insight into the cellular transformations involved in carcinogenesis. Chapter 1 provides a review of the physiological importance of PPIs and the role they play in the development and progression of cancer. A summary of the challenges associated with targeting PPIs is given, highlighting the changing perception regarding the drugabbility of PPIs and the technological and conceptual advances driving this transformation. A brief overview of the approaches used to identify PPI modulators links the reader to the appropriate chapter for further discussion and utilisation of a selection of these methods. Chapter 2 describes the application of a virtual screening approach to discover PPI modulators. In particular, the development of an in silico – in vitro screening method to identify modulators of the protein interactome of the AAA+ protein reptin. The synthesis and optimisation of two hit compounds is outlined, with a discussion of their predicted binding modes, mode of action, potential as chemical tools and lead molecules for an anti-cancer drug discovery programme. Chapter 3 highlights the potential to discover PPI modulators from Nature's rich source of structurally complex, bioactive molecules. A synthetic approach to a sub-family of tetramic acid natural products is outlined, involving the development of a short, asymmetric synthesis of unnatural 4,4-disubstituted glutamic acid derivatives. The first total syntheses of the potent siderophore harzianic acid and the PAC3 PPI inhibitor JBIR-22 are reported. In addition, the potential role of a Diels-Alderase enzyme in the biosynthesis of JBIR-22 and the development of a chiral catalysed intramolecular Diels-Alder of an advanced JBIR-22 intermediate is investigated. Chapter 4 discusses the use of structure based design techniques in the development of PPI modulators. The process involved in the design of two series of inhibitors of PICK PDZ domain mediated interactions is outlined. This leads to the development and optimisation of synthetic routes to both series of inhibitors, including the utilisation of a strategic sp3-sp2 cross coupling reaction. Finally, preliminary biological assessment of the inhibitors is reported. Chapter 5 gives a brief overview of high-throughput screening (HTS) methods used to identify PPI modulators. The utilisation of a forward chemical genetics screen to identify the p53 activator MJ05 is described. A racemic and asymmetric route to MJ05 is developed and biochemical analysis of the two enantiomers of MJ05 is reported including the investigation of MJ05 as an adjuvant therapy for the treatment of cancer. Chapter 6 provides a general overview of the outcome of the different approaches used in this research to discover PPI modulators. Particular emphasis is placed on the development of chemical tools for the elucidation and dissection of the physiological role of protein-protein interactions and the identification of novel drug targets, in addition to the identification of lead molecules for PPI drug development programmes.
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Patience, J. M. "Routes to substituted tetramic acids." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235998.
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Law, Ching-Man (Carole). "Novel tetramic acids via 1,3-dipolar cycloaddition." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/34454.
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This Ph.D. thesis has been concerned with the reinvestigation and improvement of the intermolecular 1,3-dipolar cycloaddition strategy using isoxazoles, towards the 3-acyltetramic acids (3-acylpyrrrolidine-2,4-diones) and also the investigation and development of the corresponding intramolecular strategy. A second generation of the intermolecular route was developed previously within our group and we have synthesised a variety of pyrroloisoxazoles, the 'masked' tetramic acids. We have modified and improved both the isoxazole formations and the peptide coupling reactions; we have further developed the chain extension at the isoxazole C-5 (tetramic acid C-3) substituent, testing the aldol-type reaction with some aromatic aldehydes and extending it to aliphatic aldehydes. We have demonstrated the condensation method using a strong base and hydroxyl adducts were obtained. Dehydration has been undertaken to yield the alkenyl C-5 side-chain. Development of the desmethyllaccarin, a derivative of the natural product laccarin, has also been attempted via the intermolecular route. A potential intramolecular route has the reversed sequence from the intermolecular route, by using the N-acylation product produced from an amino acid for the formation of a nitrile oxide and hence our building block pyrroloisoxazole by intramolecular dipolar cycloaddition. We have generated a nitro ketoester compound from the amino acid and investigation on the synthesis of the pyrroloisoxazole has been undertaken.
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Duller, Kathryn April Marion. "A cycloaddition route to heterocyclic tricarbonyl natural products." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307821.
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Wilson, Jason B. "Synthesis and evaluation of tetramic acids as antimicrobial agents." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-055-Wilson-Index.htm.
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Thesis (M.S.)--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on February 27, 2009). Research advisor: Richard E. Lee, Ph.D. Document formatted into pages (viii, 40 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 36-40).
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Loscher, Sebastian [Verfasser], and Rainer [Akademischer Betreuer] Schobert. "Total synthesis of naturally occurring glycosylated tetramic acids / Sebastian Loscher. Betreuer: Rainer Schobert." Bayreuth : Universität Bayreuth, 2015. http://d-nb.info/1075249473/34.
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Pingali, Subramanya. "Towards the Synthesis of Magnesidin." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/447.
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Magnesidin is a magnesium chelate of the 3-hexanoyl and 3-octanoyl tetramic acid derivatives isolated from Psuedomonas magensiorubra. Its activity against grampositive bacteria was found to be a specific target for Gingivitis, a dental plaque.Although the synthesis of magnesidin has been reported earlier, it was not reproducible. The highly polar nature and it’s ability to exhibit tautomerization makes their chemical behavior complex and difficult to predict its structure. A variety of reactions and an in depth understanding of the chemical structure is necessary to attain the synthesis of these compounds. This dissertation focuses on addressing the attempts towards the synthesis of Magnesidin by identifying the important intermediates necessary for the synthesis as β- keto esters, α,β-unsaturated amino esters. The focus of the work has been addressed by developing a TAG molecule approach, which is similar to the concept of solid phase synthesis except for the fact that the TAG molecule can be identified under UV and also can be detected using various spectroscopic techniques. Microwave synthesis has been explored and applied in to the synthesis of benzyl mono and di bromination, 1,3- benzodioxoles have been established. The benzyl mono bromination is applied to synthesize the TAG molecule, which is then applied in developing a method of synthesis for β-keto esters. The azide approach was used to synthesize the α,β- unsaturated amides, which are another essential class of compounds in the synthesis of magnesidin.
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Melanophy, Claire. "Keteneylidenetriphenylphosphorane as a C2O building block in the synthesis of highly functionalised tetramic and tetronic acids." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972529942.
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Urwin, Stephanie Jane. "Rational ligand design to support reactive main-group compounds." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31276.
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The chemistry of the tetrameric low-valent aluminium compoud (Cp*Al)4 (Cp* = 1,2,3,4,5- pentamethylcyclopentadienyl) is relatively undeveloped compared to its monomeric cousin dippNacNacAl (dippNacNac = 2,6-diisopropylphenyl-β-diketiminate). Given that the former can be formed by the reductive elimination of Cp*H from Cp*2AlH, a process common to transition metals yet rare with light main-group elements, using the Cp* ligand could unlock an abundance of unexpected reactivity for aluminium. An overview of the literature regarding the synthesis and reactivity of low oxidation state aluminium compounds is provided in chapter 1, as well as an introduction to relevant magnesium chemistry for this work. Chapter 2 studies the mechanism of C-H reductive elimination from Cp*2AlH to form (Cp*Al)4, and the properties which allow reductive elimination to take place are revealed. A transition state is identified where the Cp* group has a higher hapticity than in the starting material, a process which is thought to enable the reductive elimination. Using this insight, aluminium hydride and halide complexes featuring 9-methylfluorenyl ligands are synthesised and reduction of the aluminium centre is investigated. The reactivity of (Cp*Al)4 is considered in chapter 3 of this thesis. The formal cycloaddition reaction between (Cp*Al)4 and diphenylacetylene produces a Lewis acidic 1,4- dialuminacylohexadiene derivative. The inner Al2C4 ring of this complex is stable, with onward reactions happening at the complex's periphery. Insertion reactions in the Al-CCp* bonds are observed with unsaturated C-N species. With 2,6-dimethylphenylisonitrile the Al2C4 complex forms a zwitterionic aluminate, featuring a stable carbocation derived from the Cp* group. An amidinate complex with an unusual Cp* backbone is formed from the insertion of carbodiimides into the Al-CCp* bond of the 1,4-dialuminacyclohexadiene. Extending this, the insertion of carbon dioxide into the same bond is explored. The use of amidine ligands is common in main-group chemistry, however literature relating to the related phosphaamidinate ligands ([RPC(R)NR]-) is only reported sporadically. They have not been applied in a general manner to main-group chemistry thus far. Chapter 4 describes the synthesis of five new phosphaamidinate pro-ligands where the steric bulk of both the phosphorus and nitrogen components is increased systematically. To evaluate these new ligands, their coordination chemistry with magnesium was investigated. Three examples of heteroleptic LMgnBu (L = phosphaamidinate) complexes are synthesised, which all show high activity for the ring-opening polymerisation of racemic lactide. The resulting polylactide chains show good molecular weights and polydispersity indices. The synthesis of homoleptic L2Mg complexes is also described. Chapter 5 applies these new phosphaamidinate ligands to aluminium chemistry. An aluminium hydride species is isolated, which is shown to form via a probable lithium aluminate intermediate. The lifetime of this intermediate is found to be heavily dependent on the reaction solvent.
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Panduwawala, Tharindi. "Natural product guided antibacterial drug discovery : tetramates as core scaffolds." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:b507ca4d-ef35-4928-90a2-0a3f774a4ed2.
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This thesis describes the synthesis and biological evaluation of a library of compounds containing the tetramic acid core in search of novel antibacterial drug candidates. Chapter 1 discusses the need for new antibiotics due to the emergence of virulent bacterial strains resistant to clinically available drugs and the hiatus in the discovery of new replacement antibitoics that has become a global threat to human health. Different platforms for antibacterial drug discovery and the re-emergence of natural products-based approach that has gained importance in the quest for novel antibiotics are discussed. In this regard, the intrinsic antibacterial activity of natural products containing a tetramate core structure and the strategies developed to synthesise the core scaffold are described. Chapter 2 discusses the use of Ê-serine and Ê-cysteine in tetramic acid synthesis and the application of Ê-cysteine-derived thiazolidine templates suitable for stereoselective ring closing reactions to obtain the tetramic acid core with scope for further functionalization. Chapters 3 and 4 describe a range of synthetic routes for appropriate substitutions of the tetramate core for compound library generation. Elaboration of the tetramate core via carboxamide tetramate synthesis, Suzuki-Miyaura cross-coupling reactions, glycosylations and their aglycone analogue synthesis, etherification, tetramate-pyroglutamate systems, Buchwald aminations/amidations, cycloadditions and β-lactam hybrids as possible chemical modifications of the tetramate core structure are discussed. Chapter 5 describes the antibacetiral activity and physicochemical properties of the library of compounds synthesised. A preliminary evaluation of their antibiotic activity was conducted against S. aureus and E. coli using the hole-plate method. MICs of the tetramates synthesised were determined against several Gram-negative strains; Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Gram-positive strains; MRSA, Enterococcus faecalis and Streptococcus pneumoniae, in whole-cell bioassays. Physicochemical properties of the compound library were analysed to map the chemical space occupied by tetramates with potent antibacterial activity. Enzyme inhibition studies were conducted to identify possible modes of action that contribute to whole-cell antibiotic activity and in this regard, the inhibition of enzymes S. aureus topoisomerase IV, S. aureus RNA polymerase, E. coli RNA polymerase, E. coli gyrase and M. tuberculosis gyrase are discussed. Since plasma protein binding of compounds is an important factor that determines the bioavailability of antibiotics and their clinical outcome, a study of the binding affinity of these drug candidates to Human Serum Albumin (HSA) by both whole-cell bioassay and NMR spectroscopy-based protein binding experiments are discussed. Finally, a brief note on the potential of tetramic acids to function as proteasome inhibitors in anticancer chemotherapy is included at the end of this chapter.
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Hanneseth, Ann-Mari Dahl. "An Experimental Study of Tetrameric Naphthenic Acids atw/o Interfaces : Reactivity, Inhibition and Emulsion Formation." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemisk prosessteknologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5419.
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FELEMEZ, MARC. "Etude par rmn et potentiometrie des interactions intramoleculaires, des proprietes acido-basiques microscopiques et conformationnelles du myo-inositol 1,4,5-tris(phosphate) et d'analogues tris-et tetrakis-phosphoryles." Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13190.
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L'objet de ce travail est l'etude des proprietes acido-basiques et conformationelles d'analogues du myo-inositol 1,4,5-tris(phosphate) dont le role et l'importance biologique ont ete rappeles. Les micro et macro-constantes de protonation des ligands etudies ont ete determinees par l'intermediaire de la potentiometrie et de titrages rmn en fonction du ph. Cette approche inframoleculaire, rendant compte de l'etat de protonation de chaque phosphate, a permis d'evaluer l'influence de la nature des substituants d'un inositol-phosphate sur le comportement des noyaux 3 1p et 1h voisins. Une augmentation de l'hydrophobie locale provoque une variation vers les champs forts des signaux de ces noyaux et une augmentation de la basicite d'un groupement phosphate voisin. L'adenophostine a, seul ligand plus actif que l'ins(1,4,5)p 3, a egalement ete etudiee. Des proprietes acido-basiques proches de celles de l'ins(1,4,5)p 3 et la presence de la partie adenine sont des elements permettant d'expliquer son exceptionnelle affinite. Par ailleurs, l'etude des interactions entre les phosphates et les hydrogenes methyniques a mis en evidence la formation de liaisons hydrogene faibles de type c-ho, notamment dans le cas de l'ins(1,4,5)p 3. Les resultats de hoesy 1h- 3 1p et de titrages rmn- 1 3c ont egalement revele des interactions similaires entre des hydrogenes de ce type et des groupements phosphate. En outre, ces titrages en 1 3c ont montre une deformation du cycle du 3,4,5-tridesoxy-ins(1,2,6)p 3. Les titrages rmn- 3 1p et 1h de deux analogues deoxy ont revele des phenomenes similaires. Les groupements hydroxyles sont donc indispensables pour stabiliser la molecule en conformation chaise par l'intermediaire de liaisons hydrogene. Les titrages rmn de protons hydroxyliques ont verifie cette hypothese en montrant l'existence de liaisons hydrogene fortes entre les groupements phosphates deprotones et les hydroxyles. Ces liaisons stabilisent les protons hydroxyliques jusqu'a des valeurs de ph elevees et peuvent engendrer des variations de deplacements chimiques consequentes puisque certains signaux ont ete observes a des valeurs de l'ordre de 8 ppm. Enfin, dans la derniere partie, dediee a des etudes de complexation, le systeme ins(1,2,6)p 3/zn 2 +/spermine a montre la formation de complexes ternaires stables.
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Saleem, Saima. "A method of chemical aftertreatment for the reduction of free formaldehyde release of a durable flame retardant finished cotton fabric." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-360.
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This thesis aims at developing a method of chemical aftertreatment for reduction of free formaldehyde release of a tetrakis (hydroxymethyl) phosphonium chloride (THPC) urea precondensate, ammonia cured durable flame retardant finished cotton fabric, by preventing the formation of free formaldehyde. Formaldehyde is toxic and carcinogenic. According to the worldwide standards, acceptable limit of free formaldehyde release, for the fabrics that have skin contact, is only 75 ppm (measured by water extraction method). In this research, a cotton fabric flame retardant finished in an industrial plant in Pakistan is used. Fabric is finished by the application of THPC urea precondensate and ammonia cured, oxidized and washed. After finishing, it is not aftertreated with sodium metabisulfite that is a commonly used aftertreatment method for the reduction of free formaldehyde release. Aftertreatment with sodium metabisulfite has various problems that include large number of hot washings and there is an increase in the formaldehyde release during fabric storage. If the fabric has 75 ppm of free formaldehyde, there is often an increase in free formaldehyde release during fabric storage. There is a very limited research on the aftertreatment methods and few reports of application of these aftertreatments on flame retardant fabrics have been published. In this research, two methods of aftertreatments are developed to reduce the free formaldehyde contents to 75 ppm or less. One is the aftertreatment with a combination of resorcinol 1% and diethylene glycol 4%. The other is the combination of resorcinol 1% and boric acid 6%. For both these aftertreatments, ammonium acetate 0.5% is used as a catalyst. Fabric is padded with the solution and then dried at 130̊ C for 8 minutes. After drying, fabric is rinsed with water at 40̊ C. The aftertreatment methods developed in this research have shown a long term effect in keeping the formaldehyde release below 75 ppm during fabric storage that is not available with other conventional aftertreatment methods. These aftertreatment methods have no adverse effect on the flame retardancy of the THPC ammonia cured finished fabric and the fabric is soft as compared to the original flame retardant finished fabric and to the fabric after treated with existing methods. These new developed methods have industrial application because there is no use of any solvent and there is no use of any special equipment for the aftertreatment.
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Lesieur, Pierre. "Etude de l'orientation moléculaire dans les films de Langmuir-Blodgett." Paris 6, 1986. http://www.theses.fr/1986PA066290.
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Ce travail constitue une caractérisation des films de Langmuir-Blodgett par résonance paramagnétique électrique et par diffusion Raman résonante en lumière polarisée. Les films sont constitués de multicouches, mixtes ou alternées, de porphyrines amphiphiles et d'acide docosanoïque. Le sujet porte sur l'orientation des macrocycles porphyriniques par rapport au substrat supportant les couches
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BEBOT, BRIGAUD AGNES. "Complexes de deux inositol-phosphates : acide phytique et myo-inositol 1,2,4,5-tetrakis(phosphate) avec les cations divalents co(ii), ni(ii), cu(ii), zn(ii) et cd(ii) modelisation des interactions des cations metalliques avec des molecules biologiques issues du fractionnement de la matiere vegetale." Reims, 1998. http://www.theses.fr/1998REIMS005.
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Les proprietes acido-basiques de deux inositol-phosphates - acide phytique et myo-inositol 1,2,4,5-tetrakis(phosphate) - et leurs proprietes complexantes vis-a-vis de cinq cations metalliques divalents - co#2#+, ni#2#+, cu#2#+, zn#2#+ et cd#2#+ - ont ete etudiees, en liaison avec une eventuelle valorisation des residus vegetaux contenant des inositol-phosphates comme agents complexants. L'utilisation de la methode protometrique et du programme d'affinement protaf nous a permis de determiner les constantes d'acidite de chacun des deux ligands, ainsi que les constantes d'equilibre des complexes formes avec les differents cations metalliques dans des rapports c#l/c#m essentiellement superieurs a 1. La mobilisation du metal dans les complexes suit l'ordre : cu#2#+ > zn#2#+ > cd#2#+ > ni#2#+ co#2#+ pour les deux ligands. La resonance magnetique nucleaire du phosphore-31 a ete mise en uvre pour determiner la sequence de dissociation de l'acide phytique et les sites de coordination vis-a-vis du zinc(ii). La resonance magnetique nucleaire du proton n'a pas mis en evidence de changements conformationnels : sur l'ensemble du domaine de ph etudie, la conformation privilegiee de l'acide phytique est celle qui presente la majorite des groupements phosphate en position equatoriale, de meme que dans les complexes du zinc(ii). La spectrophotometrie d'absorption dans le visible a ete utilisee dans l'etude des complexes formes entre l'acide phytique et le cobalt(ii) et nous a permis de preciser leur geometrie : structure octaedrique en milieu acide ou neutre pour le complexe monocoordine et structure tetraedrique a ph9 pour le complexe bicoordine. L'etude des complexes solides de l'acide phytique, obtenus pour les rapports c#m/c#l > 1, tend a privilegier pour tous les cations etudies une stchiometrie m#5l, n h#2o avec n 20 ; pour m = co#2#+, la spectrophotometrie suggere une geometrie tetraedrique du complexe.
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Renaud, Jean-Paul. "Oxydations d'alcanes et d'alcènes par des systèmes métalloporphyriniques modelés du cytochrome P-450." Paris 6, 1986. http://www.theses.fr/1986PA066139.
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La synthèse d'une pophyrine de fer à "anses de panier" chirale comportant des aminoacidés de configuration déterminée est décrite. On a étudié sa pureté optique et sa conformation en solution. Dans une deuxième partie on décrit un nouveau système oxydant catalytique utilisant l'eau oxygénée en présence d'une porphyrine de manganèse et d'imidazole permettant la conversion quantitative d'alcènes en époxydes et d'alcanes en alcools et cétones.
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Su, Jia-Yi, and 蘇家誼. "A New Approach to Chiral Tetramic Acid Derivatives." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/k5w7dq.
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Su, Xin-Wei, and 蘇信維. "Dyed Application of Polylactic Acid Fabric for Tetrameric Surfactant." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/58588779355955970199.
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碩士萬能科技大學
材料科學與工程研究所
102
In this study, investigate PLA kinds of cloth adding different concentration of dye (0.3 wt%、0.6 wt%、0.9 wt%、1.2 wt%), Tetrameric surfactant (0.5g/l)and dye different temperatures (105 ℃、110 ℃、115 ℃), Determine the dye or Tetrameric additives will affect the dyeing depth and the nature of testing.Analysis by: Spectrophotometric color measurement instrument、Daylight fastness testing machine、Washing Tester、UV spectrometer、Particle size analyzer. The results,with increasing concentration of the dye and all fabric color becomes deeper, and the intensity rises. The washing fastness add Tetrameric Surfactants upward progression, colorfastness to light did not affect.After dyeing dye residue testing has added a low concentration Tetrameric Surfactants, about the particle size, adding Tetrameric Surfactants dye raffinate particles are relatively small and with good dispersion.
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Katzka, Catherine P. [Verfasser]. "Synthesis of tetramic acids and investigation of their biological properties / von Catherine P. Katzka." 2006. http://d-nb.info/997869550/34.
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Tsai, Song-Fang, and 蔡松芳. "A Kinetic Study on the Acid-Catalyzed Alcoholysis of Tetrakis (trimethylsiloxy) -silane." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/39929632543083345768.
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碩士淡江大學
化學工程學系
89
The behavior of acid-catalyzed alcoholysis reaction of room temperature vulcanized (RTV) silicone rubber was studied with the aid of a model compound. Tetrakis (trimethylsiloxy)-silane (M4Q) was chosen as a model compound for the RTV silicone rubber. Experimental results showed that the rate of disappearance of M4Q decreased as the concentrations of acid and alcohol increased. Increasing the reaction temperature, the rate of disappearance of M4Q was increased. As the reaction proceeded, the rate of disappearance of M4Q leveled off. Different alcohols were employed in the alcoholysis reaction. The rate of disappearance of M4Q was affected by the steric effect, and decreased in the order：methanol＞1-propanol＞2-propanol. Since esters were formed by the reaction of dichloroacetic acid with alcohols, the effect of esterification was included in the kinetic analysis of alcoholysis reaction system, but ester was not found in the sulfuric acid system. Mechanism and rate law of the alcoholysis reaction were proposed. Quasi-linearization method was employed to determine the kinetic parameters and activation energy. In dichloroacetic acid system, the activation energies were 27.2 kJ/mol, 35.4 kJ/mol and 44.6 kJ/mol for methanol, 1-propanol and 2-propanol, respectively. In sulfuric acid system, the activation energy was 9.3 kJ/mol methanol was used.
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Li, Yi-Feng, and 李宜峰. "Self-assembly, Structures and Properties of 1,2,4,5-Tetrakis(methylenephosphonic acid) benzene Containing Coordination Polymers." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/pzzejq.
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碩士國立臺北科技大學
化學工程研究所
100
In this thesis, a tetra-phosphonate acid ligand, 1,2,4,5-tetrakis (methylenephosphonic acid)benzene (H8tmpb), was used to react with various transition-metal ions (MnII, CoII and NiII), and alkaline earth ions (MgII, CaII and BaII), under hydrothermal process in different pH conditions. From these reactions, several coordination polymers were successfully obtained and characterized. In the first part of this report, H8tmpb was reacted with three transition-metal ions (MnII, CoII and NiII) to form four coordination polymers {[Co2(H4tmpb)(H2O)4]
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Melanophy, Claire [Verfasser]. "Keteneylidenetriphenylphosphorane as a C2O building block in the synthesis of highly functionalised tetramic and tetronic acids / vorgelegt von Claire Melanophy." 2004. http://d-nb.info/972529942/34.
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Yuan-Chang, Lo, and 羅元彰. "Synthesis and Characterization of Dimeric, Trimeric and Tetrameric Discotic Liquid Crystals Based on Dibenzo[a,c]phenazine-11-carboxylic acid." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/51196711658514672767.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
93
A homologous series of novel dimmer based on the discotic core of dibenzo[a,c]phenazine-11-carboxylic acid - α,ω-bis{2,3,6,7-tetrakis (hexyloxy)dibenzo[a,c]phenazine-11-carbonyl}alkanes, Di6-n (n=2~10), and their corresponding monomers, 2,3,6,7-tetrakis(hexyloxy)dibenzo [a,c]phenazine-11-carboxylic acid alkyl ester, Mono6-n (n=2~10),where n is the alkyl chain length of the carbon number linking the two discotic cores, have been synthesized and characterized (Scheme II and Scheme III).X-ray diffraction studies show that these dimmers exhibit a hexagonal columnar phase (Colh) with correction among the molecular cores along the column. The Colh phase of the dimmer exhibit over a wide temperature range. For example, the novel dimmer, 1,8-bis{2,3,6,7-tetrakis(hexyloxy)dibenzo[a,c]phenazine- 11-carbonyl} octane (n=8) reported here exhibits a very wide range (213℃) of glassy hexagonal columnar phase having glass transition temperature (Tg) at -20℃. The corresponding monomer, 2,3,6,7-tetrakis(hexyloxy)dibenzo [a,c]phenazine-11-carboxylic acid octyl ester (n=8) exhibits columnar phase with isotropic temperature (Ti) at 162℃ and crystallization temperature (Tc) at -20.4℃. Furthermore, two series of trimeric and tetrameric compounds by combining the dibenzo[a,c]phenazine-11-carboxyl system as the discotic core with central linking units such as 1,1,1-tris(hydroxylmethyl)ethane and pentaerythritol applying a Mitsunobu esterification reaction (Scheme IV and Scheme V). 1,1,1-tris{2,3,6,7-tetra(alkyloxy)dibenzo[a,c] phenazine-11-carboyloxymethyl}ethames, Tri-n and 1,1,1,1-tetrakis {2,3,6,7-tetra(alkyloxy)dibenzo[a,c]phenazine-11-carboyloxymethyl} methane, Tetra-n (n=3,5,8 and 10)displayed hexagonal columnar mesophases.