The goal of this project is to establish an efficient and economical industrial process for extraction of a Kaufmann and Tobschirbel orbitide (KT) mixture from flaxseed oil. KTs occur at a low level in flaxseed oil and must be concentrated at least 600 fold to produce a useful commercial concentrate. KT peptides are more polar than most lipids may be separated using solid- or liquid- phase extractants. Extraction protocols were investigated to determine a better approach for KT peptide extraction. Commercial solid-phase extraction methods would require the adaptation of bench-scale silica flash column chromatography. The first approach was to develop methods for separation of peptides using only silica, ethyl acetate and ethanol. Ethyl acetate is known to remove both oil and peptides from silica. Therefore, the ability of low temperature to decrease the peptide elution from silica was studied. The other method utilized liquid-liquid extraction. In order to measure the success of an extraction an analytical method was required to evaluate the separation of peptides from oil. An analytical procedure was developed that readily determined the relative concentration of peptide and lipid. Aqueous and anhydrous ethanol partitioning was used to extract the KT mixture from flaxseed oil. Ethanol solutions between 50 and 100% in water (v/v) were mixed with flaxseed oil. The oil and peptide content of the extracts were determined using 1H-NMR. Liquid-liquid extraction using 70% aqueous ethanol at volume ratio (solvent to oil) of 0.25:1 produced a mole ratio of 2:1 (KTs to oil) making it the optimal solvent for KT extraction. In the second part of this project, the scale of liquid-liquid extraction was increased through several 10 to 30-fold steps to establish a potential industrial extraction process for recovery of the KT mixture. The feasibility of processing the solvent containing mixed peptides was investigated. Multiple evaporation and adsorption methods were also tested, including falling film evaporation, rotary evaporation, a combination of rotary evaporation and freeze drying, and a combination of rotary evaporation and spray drying. Various experimental methods to enrich and isolate KTs from water-rich fraction were performed. At the end of this project, 3328.89 g of KT mixture was produced that was suitable for commercial purposes. The increase of extraction scale was 140,000 fold.

Red alder (Alnus rubra) is the most commercially important hardwood tree species in the Pacific Northwest and has a long history of traditional medicinal use as a source of fungicide and insecticide. Chemical analysis has shown that the diarylheptanoid oregonin ((5S)-1,7-bis(3,4-dihydroxyphenyl)-5-(β-D-xylopyranosyloxy)-heptan-3-one) is the dominant phytochemical contributing to medicinal activity. It was recently discovered that high oregonin concentration in alder leaves is associated with enhanced resistance to western tent caterpillar (Malacosoma californicum), a leaf eating lepidopteran herbivore; however, oregonin has never been directly tested on insects, or red alder-associated fungal species. In this thesis, a novel purification method was developed for the preparative extraction of oregonin from red alder leaf and bark material to directly test its biological activity. A battery of insect feeding and toxicity bioassays were carried out with several tree-defoliating caterpillars, and fungal inhibition was tested against a range of plant-associated fungal species, including several alder-associated species. This research represents the first evaluation of oregonin biological activity on insects, plant-associated fungi of the phyla Basidiomycota, and fungal-like pathogens of the phyla Oomycota. Oregonin exhibited promising insect feeding deterrent activity against generalist lepidopteran pests, including cabbage loopers (Trichoplusia ni), white-marked tussock moths (Orgyia leucostigma), and fall webworm (Hyphantria cunea) at similar concentrations shown to reduce western tent caterpillar herbivory in alder leaf bioassays. The results suggest that oregonin concentration has potential for selection as a breeding trait in managed populations of red alder to improve host resistance to leaf-eating pests. / Graduate / 2021-08-10

Department of Chemistry / MSc (Chemistry) / See the attached abstract below

No description available.

La mise au point de techniques de fractionnement des moûts de Sauvignon blanc par chromatographie de partage centrifuge et par chromatographie Flash, a permis de mettre en évidence la présence de deux « nouvelles » formes précurseurs du 3SH (le S-3-(hexan-1-al)-glutathion et l'acide S-3-glutathionyl-hydroxyhexanesulfonique). L’ensemble de ces résultats a permis de confirmer la contribution majeure des S-conjugués au potentiel en 3SH des moûts. Le S-3-(hexan-1-ol)-L-cystéine, le S-3-(hexan-1-ol)-glutathion ainsi que les deux nouvelles formes identifiées, permettent d’expliquer près de 65% du 3SH libéré dans les vins. Par ailleurs, nous avons montré que l’ensemble des formes précurseurs appartenait à la même voie d’assimilation de la levure et que le S-3-(hexan-1-ol)-L-cystéine est un intermédiaire indispensable à la biotransformation des S-conjugués au glutathion, précurseurs du 3-sulfanylhexanol. De plus, le pourcentage de biotransformation des différents S-conjugués en 3SH semble directement lié à leur position dans le flux métabolique. / The development of fractionation techniques in Sauvignon Blanc musts such as centrifugal partition chromatography and flash chromatography, permitted to identify two precursor forms of 3-sulfanylhexanol : the S-3-(hexan-1-al)-glutathione, and the S-3-glutathionyl-hydroxy hexanesulfonic acid. These results confirmed the major contribution of S-conjugates in the potential liberation of 3-sulfanylhexanol in musts. The two newly identified forms along with S-3-(hexan-1-ol)-L-cysteine and S-3-(hexan-1-ol)-glutathione, explain up to 65% of the total release of 3-sulfanylhexanol. Futhermore, we showed that all precursor forms belonged to the same assimilation pathway of yeast and the S-3-(hexan-1-ol)-L-cysteine is an essential intermediate in the metabolism of S-glutathione conjugates, which is a precursor of 3-sulfanylhexanol . Finally, the biotransformation percentage of different S-conjugates of 3-sulfanylhexanol seems directly related to their position in the metabolic flow.