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Call number: LD2668 .T4 1979 H66 / Master of Science

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Mycobacterial cell wall components have been shown to elicit a range of immunological responses in mammalian hosts. A family of cell wall antigens, the phosphatidylinositol mannans (PIMs), have been shown to reduce allergic response in a murine model of allergic airway disease and have been suggested as potential therapeutic agents. Isolation and characterisation of these compounds is not facile. To confirm the structure of PIMs a number of phosphatidylinositols (PIs), 1a-c, PIM1s 2a, 2d and 2e, and AcPIM1s, 2g and 2f, were prepared to allow assignment of the acylation pattern of natural products and for evaluation in immunological assays. As the natural products include 19:0 acylation in the form of (R)-tuberculostearoyl residues, a source of (R)-tuberculostearic acid was needed. To this end, an efficient synthesis of (R)-tuberculostearic acid from (S)-citronellol, utilising a copper-catalysed cross-coupling reaction and a modified Julia olefination, was developed. This material was incorporated into diacylglycerols prepared from (R)-benzyl glycidol. A protected myo-inositol derivative, 188, and two protected pseudo-disaccharides, 10 and 241, were prepared from myo-inositol via desymmetrisation utilising a camphylidene acetal. These were coupled with diacylglycerols via a phosphate ester and deprotected to give PIs, PIM1s and AcPIM1s. Mass spectrometry studies were undertaken on the PIs, 1a-c, PIM1s 2a, 2d and 2e, and AcPIM1s, 2g and 2f which structures that have been established by chemical synthesis. Comparison of these data with those reported for natural PIs and PIMs containing 19:0 ((R)-tuberculostearoyl) and 16:0 (palmitoyl) acyl groups unequivocally established that the 19:0 residue was located at the sn-1 and the 16:0 at the sn-2 position of the glycerol moiety in nature.

Bibliography: leaves 129-151. / xiv, 151 [65] leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1999

Hop cell wall material (CWM) extracted from hop leaves (hamulus lupulus) was purified and characterized. The total sugar content, uronic acid content and monosaccharide composition of the CWM were determined. Galacturonic acid is the major component in the CWM. A mixture of unsaturated oligogalacturonides were released from purified hop CWM by autoclaving. The biological activity of these oligomers was tested for their ability to elicit phytoalexins. The oligomer with hexagalacturonic acid possessed the greatest biological activity. Column chromatography and high-pH anion exchange chromatography were used for the sample separation and purification. Fast-atom-bombardment mass spectrometry (FAB-MS) was used for the structure elucidation. The FAB-MS spectrum showed that the unsaturated galacturonosyl residue was located at the nonreducing terminus of the oligomer. / Graduation date: 1993

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