Дисертації з теми "030502 Natural Products Chemistry"
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Handley, Paul Newton. "The chemistry of some Australian natural products /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16940.pdf.
Повний текст джерелаHeaviside, Elizabeth Anne. "Analogues of antibacterial natural products." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:6b5bd771-515b-49d0-8ec9-cee115d3aebf.
Повний текст джерелаAnderson, Margaret Marie. "Cytotoxic and antimalarial natural products." Thesis, University College London (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320404.
Повний текст джерелаvan, der Sar Sonia. "Studies in the chemistry of fungal natural products." Thesis, University of Canterbury. Chemistry, 2006. http://hdl.handle.net/10092/1333.
Повний текст джерелаHickford, Sarah Jane Herbison. "Studies in the Chemistry of Marine Natural Products." Thesis, University of Canterbury. Chemistry, 2007. http://hdl.handle.net/10092/1429.
Повний текст джерела施麗琼 and Lai-king Sy. "Structure elucidation and oxidation chemistry of natural products." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B3123768X.
Повний текст джерелаJabbar, Abdul. "The chemistry of natural products of the Rutaceae." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU498401.
Повний текст джерелаSy, Lai-king. "Structure elucidation and oxidation chemistry of natural products /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19737300.
Повний текст джерелаBlasiak, Leah Cameron. "Crystallographic studies on enzymatic halogenation of natural products." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/42914.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Vita.
Includes bibliographical references.
Halogenated natural products are common and serve roles as hormones, pesticides, antibiotics, and anti-tumor agents. The incorporation of a halogen atom into an organic scaffold can tune the molecule's potency and selectivity, making halogenation an important tailoring reaction. To understand the mechanisms of enzymatic halogenation of natural products, X-ray crystallography was used to solve structures of enzymes from two classes of halogenases, the flavin-dependent halogenases and the non-heme iron dependent halogenases. Structures of the flavin-dependent tryptophan 7-halogenase RebH from Lechevalieria aerocolonigenes, involved in rebeccamycin biosynthesis, were solved by molecular replacement. These structures show distant flavin and L-Trp binding sites and identify the conserved residue Lys79 as a likely candidate for covalent modification to produce an enzyme-bound lysine chloramine intermediate. A lysine chloramine at this position would direct the chlorination reaction to the correct site on the substrate, which could account for the halogenase's observed regioselectivity. Crystal structures of the non-heme iron-dependent threonine 4-halogenase SyrB2 from Pseudomonas syringae, involved in syringomycin biosynthesis, were solved using selenomethionine labeling and single wavelength anomalous dispersion (SAD) techniques. These structures show an overall cupin or [beta]-sandwich fold and a novel iron binding motif containing a naturally occurring iron-chloride bond. The carboxylate ligand typically found in non-heme iron dependent hydroxylases is replaced by an alanine residue in the halogenases, opening a coordination site for the halide and suggesting a mechanism by which these enzymes accomplish halogenation instead of hydroxylation.
(cont)The final chapter of this thesis reviews the known classes of halogenating enzymes and examines questions of halide binding and selectivity from the perspective of protein structure.
by Leah Cameron Blasiak.
Ph.D.
Mahaney, Paige E. (Paige Erin). "Efforts toward the synthesis of taxane natural products." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38760.
Повний текст джерелаMcAulay, Kirsten. "The total synthesis of furanocembrane natural products." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8448/.
Повний текст джерелаPasqua, Adele Elisa. "Total synthesis of enamide-containing natural products." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4088/.
Повний текст джерелаDengada, Amrapali Harishkumar. "Isolation and Structural Elucidation of Compounds from Natural Products." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64303.
Повний текст джерелаMaster of Science
Hou, Yanpeng. "Antiproliferative Natural Products from the Madagascar Rainforest." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/39467.
Повний текст джерелаPh. D.
Hans, Renate Hazel. "Novel Antimalarial and Antitubercular Agents Based on Natural Products." Doctoral thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/6311.
Повний текст джерелаClark, J. Stephen. "Approaches to the synthesis of oxocane natural products." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293810.
Повний текст джерелаNewman, Nicola Ann. "Cyclisation strategies towards the synthesis of natural products." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342637.
Повний текст джерелаBlunt, Christoper Edward. "The synthesis of benzisothiazole and benzothiazole natural products." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/49541/.
Повний текст джерелаKostiuk, Sarah Louise. "The total synthesis of macrocyclic bisbibenzyl natural products." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/193731/.
Повний текст джерелаNolan, William Peter. "Synthesis of indolo[2,3-A]carbazole natural products." Thesis, University of Cambridge, 1990. https://www.repository.cam.ac.uk/handle/1810/272982.
Повний текст джерелаLeslie, Pauline. "Studies towards the synthesis of chlorinated natural products." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268989.
Повний текст джерелаDexter, Hannah. "Towards the synthesis of heterocycle containing natural products." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/40735/.
Повний текст джерелаHariprakasha, H. K. "Synthesis Of Natural Products Based On Cyclohexadienes." Thesis, Indian Institute of Science, 1996. http://hdl.handle.net/2005/118.
Повний текст джерелаFisher, Michelle H. (Michelle Harriette). "Efforts towards the synthesis of stelliferin natural products : a thesis." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43440.
Повний текст джерелаCarazza, Rebecca J. (Rebecca Johnson) 1971. "Efforts toward the synthesis of natural products : a thesis presented." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47480.
Повний текст джерелаIncludes bibliographical references.
by Rebecca J. Carazza.
Pt. A. Paeoniflorin -- pt. B. (+)- Taxusin.
Ph.D.
Leroy, Vincent. "Studies relevant to the synthesis of nitrogen-containing natural products /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487864485229217.
Повний текст джерелаKondakal, Vishnu. "The attempted synthesis of indolizidine and pyrrolizidine natural products." Thesis, University of Huddersfield, 2013. http://eprints.hud.ac.uk/id/eprint/19281/.
Повний текст джерелаBerger, Raphaëlle. "The enantioselective total syntheses of eight cladiellin natural products." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2565/.
Повний текст джерелаWootton, R. C. R. "Synthetic approaches to polyoxygenated chromone and chromanome natural products." Thesis, University of Salford, 2000. http://usir.salford.ac.uk/2171/.
Повний текст джерелаBrooks, Steven Halton. "Studies in methodology toward the synthesis of natural products." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385612.
Повний текст джерелаChau, Yasmin-Pei(Yasmin-Pei Kamal). "Biosynthesis and medicinal chemistry of therapeutically promising plant natural products." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122839.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
Modern molecular biology, biochemical, and chemical techniques have made it possible to identify individual natural products that possess pharmacological activity from medicinal plants. While approximately 50% of all new FDA-approved small molecule therapeutics in the past 40 years were natural products or natural product analogs, challenges including limited natural resources and the difficulty of solving the total synthesis or semi-synthesis of natural products has limited our ability to harness the full diversity of chemical structures provided by nature to treat human diseases. One solution to these challenges is the elucidation of plant specialized metabolite biosynthetic pathways. Identifying and characterizing the enzymes involved in specialized metabolite biosynthesis will provide insight into the evolution of enzymes performing interesting chemistries and provide new tools for the enzymatic production of therapeutically promising natural products. The goal of this dissertation is to explore the aspects of both medicinal chemistry and the elucidation of biosynthetic pathways that can contribute to the development of novel therapeutics. First, we analyzed the structure-activity relationship of analogs of the the flavonoid icariin and identified analogs with improved potency in inhibiting human phosphodiesterase-5. We subsequently identified and characterized a novel flavonoid prenyltransferase and O-methyltransferase from the medicinal herb Epimedium sagittatum that is known to produce many bioactive prenylated and methylated flavonoids.
by Yasmin-Pei Chau.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Biological Engineering
Carter, Catherine Frances. "The application of flow chemistry to natural product synthesis." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610524.
Повний текст джерелаKhatri, Buddha Bahadur. "Photocycloaddition of Conjugated Enynes and its Application in Natural Products Synthesis." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/374648.
Повний текст джерелаPh.D.
Aromatic 2-pyridones and 2-pyrones are known to undergo a facile [4+4] photocycloaddition with themselves and other conjugated molecules. The unifying objective of this work is to explore the potential of conjugated enynes as a photocycloaddition partner with a variety of unsaturated systems and establish it as a path for the synthesis of valuable natural products and molecular scaffolds. With a 1,3-enyne as a reactant, the immediate photocycloadduct, a highly strained cyclic allene, was stabilized and functionalized to give advanced intermediates in natural product synthesis. Participation of substituted benzenes in higher order photocycloaddition with 2-pyridones was also discovered. Intramolecular enyne-pyridone [4+4] photocycloaddition led to the formation of cyclic, strained allenic products that undergo rapid dimerization through various modes leading to complex mixtures. Such allene-allene dimerization was suppressed by introducing steric shielding. With reactive tethered functional group present, the intermediate allene can undergo a secondary cycloaddition with either the proximal or distal double bond, depending on the tether length. In the absence of such functional groups, the allene can isomerize to a 1,3-diene. Oxidation of the allene led to a cyclopropanone, a bicyclo-[5.1.0]-octane, which was transformed into pseudoguaiane-like 7-5 ring systems. Participation of enynes in the photocycloaddition of other unsaturated systems was also investigated. Anthracene, naphthalene derivatives and 2-pyrones were all found to undergo quantitative photocycloaddition with an enyne. During this investigation, a low temperature Cope rearrangement was also discovered. In addition, meta-substituted benzenes were reluctant partners in [4+4] photocycloaddition with enynes but underwent efficient [4+4] photocycloaddition with 2-pyridones. The synthetic utility of enyne photocycloaddition was applied in the synthesis of the cyclooctanoid containing natural product, (+)-dactylol. The intramolecular enyne – 2-pyrone [4+4] photocycloaddition-isomerization gave a lactone bridged-cyclooctanoid product which serves as an advanced intermediate for sesquiterpene synthesis.
Temple University--Theses
Murphy, Brian Thacher. "Isolation and Structure Elucidation of Antiproliferative Natural Products from Madagascar." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29599.
Повний текст джерелаPh. D.
Fabiano, E. "Synthesis and reactions of amino compounds relating to natural products." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373890.
Повний текст джерелаCameron, J. F. "Approaches towards macrocyclic natural products using #pi#-allylnickel halide complexes." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382251.
Повний текст джерелаSigerson, Ralph Clark. "Formal synthesis of the asbestinin family of marine natural products." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3835/.
Повний текст джерелаRobinson, Anthony R. "Approaches to the synthesis of oxocane and oxonane natural products." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/273010.
Повний текст джерелаMarx, Leo. "Studies towards and total synthesis of pyrrolidinone containing natural products." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:84ac3159-3c5e-4826-89d1-4b293935ed53.
Повний текст джерелаAngell, Scott Edward. "Genomic and metagenomic approaches to natural product chemistry." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2671.
Повний текст джерелаAlmaliti, Jehad S. "Natural Products-Inspired Synthesis and Biological Evaluation of Bioactive Agents." University of Toledo Health Science Campus / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=mco1384555204.
Повний текст джерелаSirasani, Gopal. "Development of Novel Methods and Applications in Total Synthesis of Natural Products." Diss., Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/213117.
Повний текст джерелаPh.D.
The olefin cross metathesis reaction has been sequenced with four common organic transformations in a one-pot manner to rapidly access useful building blocks. Those reactions are: (1) phosphorus-based olefination (e.g., Wittig and Horner- Wadsworth-Emmons); (2) hydride reduction; (3) Evans propionate aldol reaction; and (4) Brown allyl- and Roush crotylboration. The products of these reactions include stereodefined 2,4-dienoates, trans allylic alcohols, syn-propionate aldols and chiral non- racemic homoallylic alcohols, respectively, which can be carried further in the context of chemical synthesis. Two approaches toward the total synthesis of cytotoxic polyketide natural product (+)-crocacin C have been accomplished. The first-generation approach used a Crimmins aldol reaction and reagent-controlled double asymmetric crotylboration (Brown and Roush) reaction, which was not selective. The first-generation approach was replaced altogether with a second that afforded (+)-crocacin C in 10 steps from commercially available Evans' chiral propionimide (5% overall yield). The key reactions in the second-generation approach included an Evans dipropionamide aldol reaction, 1,3-anti reduction and a vinylogous Horner-Wadsworth- Emmons olefination. No protecting groups were utilized in the total synthesis of (+)- crocacin C. A novel method to access the ABCE tetracyclic framework of the Strychnos alkaloids has been developed. Five different strategies were utilized toward this goal, out of which the first four were unsuccessful. The fifth-generation strategy featured a novel sequential one-pot bis-cyclization method. Specifically, the AgOTf-mediated spirocyclization of an appropriately functionalized indole 3-carbinamide afforded a stable spiroindolenine intermediate; subsequent addition of DBU to the reaction mixture effected an unprecedented intramolecular aza-Baylis-Hillman reaction, delivering tetracyclic product in 70% isolated yield. The bis-cyclization was showcased in concise racemic total syntheses of akuammicine and strychnine in six and thirteen operations, respectively. Key steps include (1) the vinylogous Mannich reaction; (2) our sequential one-pot spirocyclization/intramolecular aza-Baylis-Hillman reaction; and (3) a Heck cyclization. The synthesis of strychnine proceeded via the Wieland-Gumlich aldehyde. We have also utilized our method to prepare other biologically active Strychnos alkaloids (-)- akuammicine, (-)-leuconicines A and B, (-)-norfluorocurarine, (-)-dehydrotubifoline, (-)- dihydroakuammicine, (-)-tubifoline and (-)-valparicine in a concise, asymmetric manner.
Temple University--Theses
Kulyk, Svitlana. "PYRIDONE PHOTOCYCLOADDITION IN SYNTHESIS OF DIVERSE NATURAL AND UNNATURAL PRODUCTS." Diss., Temple University Libraries, 2014. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/250995.
Повний текст джерелаPh.D.
2-Pyridones are known to undergo a facile [4+4] photocycloaddition with themselves and other conjugated molecules. These transformations provide an access to complex molecular structures such as highly substituted cyclooctanoid derivatives, which normally represent a significant synthetic challenge. Moreover, the 2-pyridone photoadducts can be further elaborated into various biologically relevant products. The work presented here broadens the horizons of the [4+4] photocycloaddition in two distinct directions: 1) by utilizing [4+4] photocycloaddition in a total synthesis of crinipellin natural products possessing antibiotic and antitumor activity and 2) by developing a novel type of [4+4] photocycloaddition that employs a conjugated enyne as a partner of 2- pyridone. Our approach to the tetraquinane core of the crinipellins features intramolecular [4+4] photocycloaddition of a tethered furan-pyridone molecule followed by a four-step transannular ring closure. The sequence allows for a rapid assembly of a molecular framework by installing 19 of the 20 required carbon atoms and all but two stereogenic centers. The described synthesis represents an interesting new approach to these polycyclic molecules and a way to access crinipellin analogues. The enyne-pyridone [4+4] photocycloaddition led to formation of intriguing 1,2,5-cyclooctatriene-based products. Presence of the allene functionality was used as a lever in exploring the possibilities for derivatization of these photoadducts. Our investigations of enyne-pyridone photocycloaddition have come a long way: from the first proof-of-concept intermolecular trials producing complex mixtures, through the initial investigations of the intramolecular variant that taught us how to direct the reaction to the necessary mode ([2+2] vs. [4+4] photocycloaddition), and eventually to the controlled formation of stable allenic photoadducts and their further transformation into a diverse set of functionalized molecular scaffolds. We found that the inherent kinetic instability of 1,2,5-cyclooctatrienes facilitates several pathways of strain relief: allene-allene [2+2] dimerization, photooxidative decarbonylation when the irradiation is conducted in presence of air, isomerization of the 1,2-diene fragment into a 1,3-diene and the acid-promoted Cope rearrangement. Additionally, enyne-pyridone photoadducts can undergo transannular ring closure when treated with bromine and also be transformed into valuable bicyclo [5.1.0] octane structures that incorporate a rare example of a stable cyclopropanone by a fast and selective epoxidation-rearrangement process. Several important goals were achieved in the described research study. First, strategic incorporation of [4+4] photocycloaddition as one of the key steps in targeted synthesis of natural products has demonstrated the potential of this powerful reaction. Second, an efficient new approach to a tetraquinane skeleton was developed and successfully executed. Third, the fundamental basis for the novel photochemical transformation (enyne-pyridone cycloaddition) was set and major trends for this reaction were established resulting in obtaining stable allenic photoadducts. Finally, chemical properties and reactivity of stabilized amide-bridged 1,2,5-cyclooctatriene photoproducts were investigated breaking the ground for future involvement of these intermediates in synthetic strategies towards biologically active natural products and their analogues.
Temple University--Theses
Turkut, Engin. "Chemoenzymatic Synthesis Of Biologically Active Natural Products." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12604854/index.pdf.
Повний текст джерела#65533
s precursor, 5-(hydroxymethyl)-2-cyclohexen-1-ol (19), was synthesized by iodolactonization, followed by iodine elimination and the reduction of the lactone. In connection with this work, alpha,beta-unsaturated and saturated cyclic ketones were selectively oxidized on alpha'
- and alpha-positions using Mn(OAc)3 and Pb(OAc)4, respectively. The resultant racemic alpha'
- and alpha-acetoxylated substrates were resolved into corresponding enantiomerically enriched alpha'
- and alpha-hydroxylated and acetoxylated compounds via PLE hydrolysis.
Hancock, William Stephen. "Study of the chemistry of natural products: collected reprints 1970-1992." 1992, 1992. http://hdl.handle.net/2440/38509.
Повний текст джерелаHancock, William Stephen. "Study of the chemistry of natural products: collected reprints 1970-1992." Thesis, 1992, 1992. http://hdl.handle.net/2440/38509.
Повний текст джерелаPersichini, Phillip John. "The chemistry and use of pyrroline ring systems in the synthesis of natural products." Master's thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-03302010-020511/.
Повний текст джерелаWu, Boshen. "Synthesis of taurospongin A and other biologically active natural products." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:37a34bc4-efb4-4a6b-9d44-a3ad1c8ae0be.
Повний текст джерелаStefinovic, Marijan. "Novel synthetic and mechanistic metholologies for the construction of natural products." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385614.
Повний текст джерелаRomiti, Filippo. "Total synthesis of members of the amphidinolide family of natural products." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6445/.
Повний текст джерела