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Preparation and modification of cellooligosaccharides

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dc.contributor.advisor Penner, Michael H.
dc.creator Akpinar, Ozlem
dc.date.accessioned 2012-01-27T15:46:37Z
dc.date.available 2012-01-27T15:46:37Z
dc.date.copyright 2002-09-05
dc.date.issued 2002-09-05
dc.identifier.uri http://hdl.handle.net/1957/27274
dc.description Graduation date: 2003 en_US
dc.description.abstract Cellooligosaccharides are the reaction intermediates produced during the hydrolysis of cellulose to glucose. Hence, they have the same chemical structure as cellulose, just shorter chain lengths. Cellooligosaccharides up to DP eight are soluble in water. The soluble cellooligosaccharides can be used "as is" in the food industry as non-digestible oligosaccharides and in the laboratory as representative substrates for cellulolytic enzymes. The soluble cellooligosaccharides may also be chemically modified for use in the laboratory, in this case serving as affinity ligands, reporter groups, or model substrates. A number of methods are available for the separation of cellooligosaccharides differing only with respect to DP. This type of separation is relevant to both laboratory and industrial applications. A new approach to the chromatographic separation of cellooligosacchandes is presented in this thesis. It is shown that cellulose stationary phases, in conjunction with ethanol-water mobile phases, may be used for cellooligosaccharide fractionation. The system appears to behave as an affinity/partition system, with retention times increasing as the DP of the cellooligosaccharides increase. The feasibility of using such a chromatographic system for the "clean-up" of cellooligosaccharide mixtures is demonstrated. The relative merit of different chromatographic approaches putatively used for the fractionation of cellooligosaccharides was determined. Affinity-, adsorption-, ion-mediated- and molecular exclusion-approaches were tested. Adsorption chromatography, using a charcoal-celite stationary phase, was the most generally applicable method for the preparation of near gram quantities of pure cellooligosaccharides. Cellulose-based affinity/partition chromatography was found to be the least time consuming and most economical method for the preparation of cellotetraose and cellopentaose. Studies using chemically modified cellooligosaccharides are typically limited to derivatives whose aglycone group is conjugated to the reducing end of the sugar. This is because the chemistry involved in modifying the reducing end is typically much easier than that involved in selectively modifying other sites on the oligosaccharides. A portion of the studies presented herein was aimed at exploring approaches for the modification of the non-reducing end of cellooligosaccharides. Methyl 6-O-p-nitrobenzoyl-β-D-glucoside was synthesized by reacting methyl 4,6-O-p-nitrobenzylidine-β-Dglucoside with N-bromosuccinimide. This method has potential as a general method for the modification of the reducing terminus of oligosaccharides, including, cellooligosaccharides. en_US
dc.language.iso en_US en_US
dc.subject.lcsh Oligosaccharides -- Synthesis en_US
dc.subject.lcsh Cellulose -- Chemistry en_US
dc.title Preparation and modification of cellooligosaccharides en_US
dc.type Thesis/Dissertation en_US
dc.degree.name Doctor of Philosophy (Ph. D.) in Food Science and Technology en_US
dc.degree.level Doctoral en_US
dc.degree.discipline Agricultural Sciences en_US
dc.degree.grantor Oregon State University en_US
dc.contributor.committeemember Cherian, Gita
dc.contributor.committeemember Williams, David E.
dc.contributor.committeemember Kennedy, James
dc.description.digitization File scanned at 300 ppi (Monochrome, 256 Grayscale) using Scamax Scan+ V. on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V. used for pdf compression and textual OCR. en_US
dc.description.peerreview no en_us

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