Graduate Thesis Or Dissertation
 

Preparation and modification of cellooligosaccharides

Público Deposited

Conteúdo disponível para baixar

Baixar PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/j098zd87r

Descriptions

Attribute NameValues
Creator
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.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Declaração de direitos
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Relações

Parents:

This work has no parents.

Em Collection:

Itens

Miniatura Título Data de carga Acesso Ações
file details AKPINAROZLEM2002.pdf 2017-08-15 Público Baixar