Functional and anionic cellulose-interacting polymers by selective chemo-enzymatic carboxylation of galactose-containing polysaccharides.
Carboxylated, anionic polysaccharides were selectively prepared using a combination of enzymatic and chemical reactions. The galactose-containing polysaccharides studied were spruce galactoglucomannan, guar galactomannan, and tamarind galactoxyloglucan. The galactosyl units of the polysaccharides were first oxidized with galactose oxidase (EC 1.1.3.9) and then selectively carboxylated, resulting in the galacturonic acid derivatives with good conversion and yield. The degrees of oxidation (DO) of the products were determined by gas chromatography-mass spectrometry (GC-MS). A novel feasible electrospray ionization-mass spectrometry (ESI-MS) method was also developed for the determination of DO. The solution properties and charge densities of the products were investigated. The interaction of the products with cellulose was studied by two methods, bulk sorption onto bleached birch kraft pulp and adsorption onto nanocellulose ultrathin films by quartz crystal microbalance with dissipation (QCM-D). To study the effect of the location of the carboxylic acid groups on the physicochemical properties, polysaccharides were also oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated reaction producing polyuronic acids. The chemo-enzymatically oxidized galacturonic polysaccharides with an unmodified backbone had a better ability to interact with cellulose than the TEMPO-oxidized products. The selectively carboxylated polysaccharides can be further exploited, as such, or in the targeted functionalization of cellulose surfaces.
Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland. kirsti.parikka@helsinki.fi
Kirsti
K
Parikka
Ann-Sofie
AS
Leppänen
Chunlin
C
Xu
Leena
L
Pitkänen
Paula
P
Eronen
Monika
M
Osterberg
Harry
H
Brumer
Stefan
S
Willför
Maija
M
Tenkanen
D000327:Adsorption; D000465:Algorithms; D000838:Anions / Q000737:chemistry; D055162:Biocatalysis; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry; D003497:Cyclic N-Oxides / Q000737:chemistry; D005685:Galactans / Q000737:chemistry*; D005692:Galactose Oxidase / Q000737:chemistry; D005936:Glucans / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D008027:Light; D008351:Mannans / Q000737:chemistry*; D008970:Molecular Weight; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D053149:Plant Gums / Q000737:chemistry*; D011193:Potassium Iodide / Q000737:chemistry; D012542:Scattering, Radiation; D021241:Spectrometry, Mass, Electrospray Ionization; D014783:Viscosity
D000838:Anions; D002264:Carboxylic Acids; D002712:Chlorides; D003497:Cyclic N-Oxides; D005685:Galactans; D005936:Glucans; D008351:Mannans; D016877:Oxidants; D053149:Plant Gums; C443804:galactoglucomannan; D011193:Potassium Iodide; D002482:Cellulose; C007894:guar gum; D005692:Galactose Oxidase; C003959:TEMPO; C001599:chlorite