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Spherulitic Crystallization of Chitosan Oligomers
Langmuir, 1999Chitosan crystallization, performed by simple drying of an oligomer or polymer solution on a glass or mica surface, was studied at room temperature. Polarizing microscopy revealed the formation of two-dimensional spherulites that were shown to have a negative birefringence. After metal shadowing, electron microscopy investigations allowed the molecular
Belamie, E. +3 more
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2006
Oligomers of chitosan carrying 45 units long poly(ethylene oxide), PEO, chains grafted to the C-6 position of the sugar units were prepared using a novel synthesis route. The graft density was high, close to one poly(ethylene oxide) chain grafted to each sugar unit of the chitosan oligomer but a small fraction of unreacted chitosan remained in the ...
Andra Dedinaite +4 more
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Oligomers of chitosan carrying 45 units long poly(ethylene oxide), PEO, chains grafted to the C-6 position of the sugar units were prepared using a novel synthesis route. The graft density was high, close to one poly(ethylene oxide) chain grafted to each sugar unit of the chitosan oligomer but a small fraction of unreacted chitosan remained in the ...
Andra Dedinaite +4 more
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Enzymatic sequencing of partially acetylated chitosan oligomers
Carbohydrate Research, 2014Chitosan oligosaccharides have diverse biological activities with potentially valuable applications, for example, in the fields of medicine and agriculture. These functionalities are thought to depend on their degree of polymerization and acetylation, and possibly on specific patterns of acetylation.
Stefanie Nicole Hamer +2 more
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Antibacterial activity of chitosans and chitosan oligomers with different molecular weights
International Journal of Food Microbiology, 2002Antibacterial activities of six chitosans and six chitosan oligomers with different molecular weights (Mws) were examined against four gram-negative (Escherichia coli, Pseudomonas fluorescens, Salmonella typhimurium, and Vibrio parahaemolyticus) and seven gram-positive bacteria (Listeria monocytogenes, Bacillus megaterium, B.
Hong Kyoon, No +3 more
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Preparation of chitosan oligomers by irradiation
Polymer Degradation and Stability, 2002Abstract Chitosans (20 and 100 cp, 2%) were irradiated in acetic acid solution (2%) with different doses (2–200 kGy) of Co-60 gamma rays to investigate the yields of chitosan oligomers. A rapid decrease of viscosity was observed up to 10 kGy and then the viscosity decrease slowed down gradually with increasing irradiation dose.
Won-Seok Choi +4 more
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Measurement of molecular mass of chitosan oligomers
Polymer Science Series B, 2006The molecular mass of chitosan oligomers in the range of (2-5) × 103 was measured using viscometry and gel permeation chromatography. The use of viscometers with a flow time of at least 108 s (0.33 M CH3COOH + 0.3 M NaCl as a solvent, 21°C, [η] = 3.41M 1.02) makes it possible to determine the molecular mass of chitosan oligomers up to 1.
E. I. Cherkasova +2 more
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Radiation depolymerization of chitosan to prepare oligomers
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2003Abstract Radiation depolymerization of chitosan was carried out by gamma irradiation in the solid state. The radiation-chemical depolymerization yield of chitosan in the solid state, Gd, determined by gel permeation chromatography, is 0.9 for chitosan 10B and 1.8 for chitosan 8B.
Le Hai +4 more
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Preparation of chitosan oligomers by immobilized papain
Enzyme and Microbial Technology, 2002Abstract Immobilized papain was used to prepare chitosan oligomers and the optimum conditions were as follows: NaAc–HAc buffer system, pH 4.0, temperature 45 °C. After 24 h reaction with stirring, nanofiltration and ultrafiltration were used to desalt and isolate chitosan oligomers into different molecular weight fractions respectively.
Hong Lin +3 more
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Analysis of antioxidant properties of chitosan and its oligomers
Bulletin of Experimental Biology and Medicine, 2006Oral treatment with chitosan with a molecular weight approximately 105, but not its oligomer, reduced plasma content of free-radical oxidation products in normal rats and animals treated for the bone marrow form of radiation sickness and stimulated the recovery processes in involved bone marrow and peripheral blood.
A S, Koryagin +5 more
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