Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

In part A, a much sought synthesis of the calycanthaceous alkaloids is described. Oxidative dimerization of N- methyltrytamine afforded dl- chimonanthine and meso-chimonanthine, and dl- calycanthine was produced by subsequent acid-catalyzed rearrangement of the carbon skeleton through a tetraminodialdehyde. As the suggested biosynthesis of these alkaloids is represented as occurring by an oxidative dimerization of N- methyltryptamine (itself a natural product) the very direct synthesis described is a biosynthetic model. The discovery of meso-chimonanthine in an extract of Calycanthus f1oridus is also reported and is the first natural calycanthaceous alkaloid with this stereochemistry to be discovered. As folicanthine and calycanthidine are N-methyl chimonanthines and this methylation has been reported, a synthesis of chimonanthine also represents a formal synthesis of these alkaloids. A proposal for the structure of hodgkinsine, the remaining calycanthaceous alkaloid, is made. A number of synthetic by-products are also described. In part B evidence for the mono-terpenoid origin of the nine or ten carbon non-tryptophan derived portion of the indole alkaloids is presented. The monoterpene, geraniol- 2- ¹⁴C, was administered to Vinca rosea cuttings and the Aspidosperma- type alkaloid, vindoline, was isolated and shown by Kuhn-Roth degradation to be labelled at C-5 as predicted by theory. Feeding experiments with mevalonic acid- 2- ¹⁴C are also described. / Science, Faculty of / Chemistry, Department of / Graduate

</p> Part I The mass spectra of the seven isomeric monomethoxyquinolines, the seven monohydroxyquinolines, the two N-methylquinolones and six furoquinoline alkaloids have been recorded. Fragmentation mechanisms are proposed to account for the major peaks in all the spectra. Use has been made of intense metastable peaks found in most of the spectra to aid the interpretation of the fragmentation routes. In addition, deuterium and carbon-13 labelling have been employed in analyzing the fragmentation routes of the methoxyquinolines. </p> <p> Part II The Hofmann degradation of lobinaline is described. Examination of lobinaline, its derivatives and its Hofmann degradation products by mass spectrometry and other physical and chemical techniques has allowed a structure to be assigned to the alkaloid.</p> / Thesis / Doctor of Philosophy (PhD)

<p> The biosynthesis of the alkaloids of Decodon verticillatus, (L.)Ell, a member of the Lythraceae family, was studied by tracer methods. These alkaloids contain a phenylquinolizidine system, whose biosynthetic origin has not previously been investigated.</p> <p> Labelled samples of lysine, △^1-piperideine and phenylalanine yielded radioactive decodine and decinine, the two major alkaloids of D. verticillatus. Systematic degradations of these labelled alkaloids show that lysine, △^1-piperideine and phenylalanine serve as specific precursors. Whereas lysine and △^1-piperideine entered the quinolizidine ring, the biphenyl ring system of these alkaloids was derived from two units of phenylalanine. In a further experiment, labelled pelletierine was administered to the plants. But this experiment yielded an inconclusive result.</p> / Thesis / Doctor of Philosophy (PhD)

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Tabernaemontana johnstonii is a medium-sized tree native to Africa. Specimens of the hardwood of the plant were procured from the United States Department of Agriculture in cooperation with the cancer chemotherapy program initiated by the National Institutes of Health (NIH). An investigation was undertaken to verify that the plant possessed activity in the anti-tumor bioassay tests conducted by the NIH. Consequently, systematic fractionation of the plant in conjunction with bioassay revealed that the biological activity was concentrated in the alkaloidal portion of the plant material. Purification of the crude alkaloidal material was accomplished initially by a combination of liquid chromatography on alumina followed by buffer extraction, and subsequently, by liquid chromatography on alumina followed by liquid chromatography on silica gel. Four crystalline alkaloids were isolated during the purification procedure. Two of these alkaloids, isovoacangine and perivine, were characterized by absorption spectroscopy and mass spectrometry. Their identity was verified by comparison with authentic samples. The remaining two alkaloids were shown by nuclear magnetic resonance and mass spectrometry to be isomeric with the known bisindole alkaloid voacamine. These two alkaloids were subsequently identified as conodurine and conoduramiae, and their structural assignments were verified by comparison with authentic samples. Each of the isolated alkaloids was submitted for bioassay in the KB in vitro and the PS in vitro test. Only conodurine and conduramine showed KB activity with values of 31 g/ml and 19 g/ml respectively. All four alkaloids showed PS activity arid the following values were obtained: perivine (20 g/ml), isovoacangine (18 g/ml), conodurine (29 g/ml), and conoduraaine (20 g/ml). / Master of Science

Part (i) -The Minor Alkaloids: Annotoxine, C32H44O5N2, has now been isolated from a Canadian source. It has been separated into the alkaloids acrifoline, C16H23O2N, and annotine (alkaloid L 11), C16H21O3N. Both alkaloids have been shown to possess one hydroxyl group, one carbonyl group and one centre of unsaturation. The lack of reactivity of the third oxygen function of annotine suggests that it is present in an ether linkage. The identity of O-acetylacrifoline with alkaloid L 12 has also been proved. Part (ii) -Diphenylannotinine: Diphenylannotinine has been shown to be C28H33O3N. It possesses two hydroxyl groups, the third oxygen is present in an ether linkage. The exact nature of the ether linkage could not be ascertained on the basis of the experimental evidence. / Thesis / Master of Science (MSc)

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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