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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The asymmetric synthesis of polyhydroxylated pyrrolizidine alkaloids

Tang, Minyan. January 2004 (has links)
Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 236-249.
22

Schema voor microchemische identificatie van alkaloïden ...

Amelink, Johan Felix Herman. January 1928 (has links)
Thesis--Utrecht, 1928. / Bibliography, p. [147]-149.
23

Studies in alkaloid chemistry

Suffness, Matthew. January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
24

Schema voor microchemische identificatie van alkaloïden ...

Amelink, Johan Felix Herman. January 1928 (has links)
Thesis--Utrecht, 1928. / Bibliography, p. [147]-149.
25

Synthetic approaches to the alkaloids cycleanine, insularine and cissacapine

Maumela, Munaka Christopher 14 August 2012 (has links)
Ph.D. / The objective of the research described in this thesis was to develop a synthetic method that can be applied to the synthesis of the natural bisbenzyltetrahydroisoquinoline alkaloids cissacapine, insularine, insularoline, cycleanine and analogues thereof. In this study two different strategies that allow easy entry to the precursors of these alkaloids were developed, and these set the scene for future total synthesis of these alkaloids. The key features of the first approach comprise the linkage of the two appropriate rings to form the diaryl ether moiety as well as the preparation of the 11H-dibenzo[b,e][1,4]dioxepine tricyclic system. Previous approaches to the diaryl ether formation are not suitable for large-scale reactions. We have herein described the preparation of the diaryl ether precursors in high yields and our approach is suitable for large-scale preparations. A search of the literature method revealed only two published methods for the preparation of the 11H-dibenzo[b,e][1,4]dioxepine system. Both these two methods produce compounds containing this moiety in low yields. In our studies this aspect was addressed satisfactorily. Unfortunately, our attempts to complete the synthesis of these alkaloids through Bischler-Napieralski reaction was met with no success, the problem been ascribed to the unoptimised Bischler-Napieralski conditions used. Our second approach involves the preparation of benzylisoquinoline units that are precursors of cycleanine. The published method to the derivatives of the cycleanine precursors is non-stereopecific and produces racemic benzylisoquinolines. Our synthetic route is a chiral auxiliary-based asymmetric version that produces the optically-pure benzylisoquinoline monomers. The key features of this route involve incorporation of the chiral auxiliary on the nitrogen atom, Bischler-Napieralski cyclisation of the resultant chiral amides and finally stereoselective reduction of the 3,4-dihydroisoquinolinium ion possessing the chiral auxiliary. This route employs both optically-pure (S)- and (R)-1-phenethylamine as the chiral source. Optically pure diastereomers were obtained. Our approach is a vast improvement compared to the previously described non-stereospecific method since it allows easy and good stereoselective access to both diastereomers in good yield. Unfortunately, one of the concluding steps leading to the formation of the dimeric stereoisomers of cycleanine through diaryl ether formation using the recently published methods was not successful. This is ascribed to the electron-rich nature of the isoquinoline ring.
26

The biological activities of narciclasine.

January 2002 (has links)
Wong Chi-Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 119-132). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iv / List of Abbreviations --- p.v / List of Figures --- p.vii / List of Tables --- p.ix / Chapter 1 --- Introduction / Chapter 1.1 --- Plant secondary metabolites --- p.1 / Chapter 1.2 --- Plant alkaloids --- p.6 / Chapter 1.3 --- Narciclasine --- p.12 / Chapter 1.3.1 --- Isoquinoline alkaloids --- p.12 / Chapter 1.3.2 --- Amaryllidaceae alkaloids --- p.14 / Chapter 1.3.3 --- Narcissus --- p.16 / Chapter 1.3.4 --- Narciclasine --- p.17 / Chapter 1.3.4.1 --- Isolation --- p.17 / Chapter 1.3.4.2 --- Biological and pharmaceutical functions --- p.20 / Chapter 1.3.5 --- High performance liquid chromatography (HPLC) --- p.23 / Chapter 1.3.6 --- In vitro protein synthesis --- p.24 / Chapter 1.3.6.1 --- Rabbit reticulocyte lysate --- p.25 / Chapter 1.3.6.2 --- Wheat germ extract --- p.25 / Chapter 1.3.6.3 --- Non-radioactive colorimetric detection system --- p.26 / Chapter 1.4 --- Objective --- p.28 / Chapter 2 --- Materials and Methods / Chapter 2.1 --- Plant materials --- p.29 / Chapter 2.2 --- Extraction of narcicalsine --- p.29 / Chapter 2.3 --- Distribution of NCS in Narcissus tazetta --- p.30 / Chapter 2.4 --- Stability test --- p.31 / Chapter 2.4.1 --- HPLC analysis --- p.31 / Chapter 2.4.1.1 --- HPLC system --- p.31 / Chapter 2.4.1.2 --- Analytical condition --- p.31 / Chapter 2.4.2 --- Seed germination assay --- p.32 / Chapter 2.5 --- Mode of action of NCS --- p.33 / Chapter 2.5.1 --- In vitro translation --- p.33 / Chapter 2.5.1.1 --- In vitro translation --- p.33 / Chapter 2.5.1.2 --- SDS-PAGE analysis --- p.33 / Chapter 2.5.1.3 --- Western blot analysis --- p.34 / Chapter 2.5.1.4 --- Colorimetric detection --- p.34 / Chapter 2.5.2 --- Assay of induction of a-amylase synthesis in aleurone cells of barley grains by GA3 --- p.36 / Chapter 2.5.2.1 --- Chemicals and reagents --- p.36 / Chapter 2.5.2.2 --- Reducing sugar assay --- p.37 / Chapter 2.5.3 --- Root tip smear --- p.43 / Chapter 2.5.3.1 --- Chemicals and reagents --- p.43 / Chapter 2.5.3.2 --- Assay --- p.43 / Chapter 2.6 --- Allelopathic test --- p.45 / Chapter 2.6.1 --- Soil planting --- p.45 / Chapter 2.6.1.1 --- Foliage spray --- p.45 / Chapter 2.6.1.2 --- Planting with Narcissus bulb --- p.45 / Chapter 2.6.2 --- Hydroponics --- p.46 / Chapter 2.7 --- Effect of NCS on plant cells via tissue culture --- p.48 / Chapter 2.7.1 --- Establishment of tissue culture system --- p.48 / Chapter 2.7.1.1 --- Initiation and maintenance of carrot callus --- p.48 / Chapter 2.7.1.2 --- Initiation and maintenance of tobacco callus --- p.49 / Chapter 2.7.1.3 --- Initiation and maintenance of Narcissus callus --- p.50 / Chapter 2.7.1.4 --- Optimisation of callus growth --- p.50 / Chapter 2.7.2 --- Effects of NCS --- p.51 / Chapter 2.7.3 --- Effect of tobacco extract on NCS --- p.51 / Chapter 2.7.3.1 --- Extraction of tobacco extract --- p.51 / Chapter 2.7.3.2 --- Bioassay --- p.52 / Chapter 2.8 --- Assay of effect of NCS on microorganisms --- p.53 / Chapter 2.8.1 --- Antibacterial activity --- p.53 / Chapter 2.8.1.1 --- Total bacterial count --- p.53 / Chapter A. --- Chemicals and reagents --- p.53 / Chapter B. --- Serial dilution --- p.54 / Chapter C. --- Assay --- p.54 / Chapter 2.8.1.2 --- Turbidity test --- p.55 / Chapter A. --- Bacteria --- p.55 / Chapter B. --- Chemicals and reagents --- p.55 / Chapter C. --- Assay --- p.55 / Chapter 2.8.2 --- Anti-fungal and anti-yeast activity --- p.56 / Chapter 2.8.2.1 --- Disc diffusion method --- p.56 / Chapter A. --- Fungi --- p.56 / Chapter B. --- Chemicals and reagents --- p.56 / Chapter C. --- Assay --- p.56 / Chapter 2.8.2.2 --- Tube dilution method --- p.57 / Chapter A. --- Yeast --- p.57 / Chapter B. --- Chemicals and reagents --- p.57 / Chapter C. --- Assay --- p.57 / Chapter 2.9 --- Statistical analysis / Chapter 3 --- Results / Chapter 3.1 --- Distribution of NCS in Narcissus tazetta --- p.59 / Chapter 3.2 --- Stability of NCS --- p.62 / Chapter 3.2.1 --- HPLC analysis --- p.62 / Chapter 3.2.2 --- Bioassay --- p.62 / Chapter 3.3 --- Mode of action of NCS --- p.66 / Chapter 3.3.1 --- In vitro translation --- p.66 / Chapter 3.3.2 --- Effect ofNCS on the induction of a-amylase synthesis in aleurone cells of barley grains by GA3 --- p.69 / Chapter 3.3.3 --- Root tip smear --- p.74 / Chapter 3.4 --- Allelopathic test --- p.77 / Chapter 3.4.1 --- Soil planting --- p.77 / Chapter 3.4.1.1 --- Foliage applications --- p.77 / Chapter 3.4.1.2 --- Planting with Narcissus bulb --- p.77 / Chapter 3.4.2 --- Hydroponics --- p.78 / Chapter 3.5 --- Effect of NCS on plant cells via tissue culture --- p.91 / Chapter 3.5.1 --- Optimisation of Narcissus callus growth --- p.91 / Chapter 3.5.2 --- "Effects of NCS on Narcissus, carrot and tobacco calli" --- p.91 / Chapter 3.5.3 --- Effect of tobacco extract on NCS --- p.91 / Chapter 3.6 --- Effect of NCS on microorganisms --- p.95 / Chapter 3.6.1 --- Antibacterial activity --- p.95 / Chapter 3.6.1.1 --- Total bacterial count --- p.95 / Chapter 3.6.1.2 --- Turbidity test --- p.95 / Chapter 3.6.2 --- Anti-fungal and anti-yeast activities --- p.95 / Chapter 3.6.2.1 --- Disc diffusion method --- p.95 / Chapter 3.6.2.2 --- Tube dilution method --- p.96 / Chapter 4 --- Discussion / Chapter 4.1 --- General properties --- p.103 / Chapter 4.2 --- Mode of action --- p.105 / Chapter 4.3 --- Other biological properties --- p.108 / Chapter 4.3.1 --- Allelopathic property --- p.108 / Chapter 4.3.2 --- Effect on other plants via tissue culture --- p.110 / Chapter 4.3.3 --- Effect on microoraganisms --- p.112 / Chapter 4.4 --- Further studies --- p.114 / Chapter 5 --- Conclusion --- p.115 / Appendix --- p.116 / References --- p.119
27

Syntheses of the alkaloid, graveoline and related methylenedioxy 2-aryl-4-quinolones [sic]

駱韞珊, Loh, Yung-sen, Lucy. January 1962 (has links)
published_or_final_version / Chemistry / Master / Master of Science
28

Synthetic studies towards manzamine A

McMath, Alwyn Francis January 2001 (has links)
No description available.
29

New routes to chiral aminocyclohexenes

Reynolds, Karen January 1996 (has links)
No description available.
30

Studies towards the synthesis of frog alkaloid 251F.

Jamieson, Scott, Gordon. January 2004 (has links)
No abstract available / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

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