• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.247-251
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• 1999

In spite of various bio-functionalities of chitosan, the effects in vivo were still ambiguous because of its low absorption on organism. Therefore, chitosan oligosaccharides (COSs) are necessary to elucidate for an efficient utilization in vivo. COSs were prepared from chitosan using ultrafiltration membrane enzymatic reactor system with MWCO (molecular weight cut-off) 3,000 Da of membrane. Calcium absorption accelerating effect using COSs was examined by two methods, in vitro and in vivo. In vitro experiment, calcium absorption by the addition of COSs in a mixture solution of calcium and phosphate was higher approximately $50\%$ than that by control. In vivo using rats, group taken the diet contained $1\%$ COSs anil calcium chloride decreased about $75\%$ of calcium content excreted from feces, and then, showed about $15\%$ increase in breaking force of femur. These results demonstrated that COSs definitely involved in calcium metabolism in vivo.

• Polymer(Korea)
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• v.38 no.1
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• pp.85-92
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• 2014

To develop water-soluble chitosan as an effient gene delivery carrier, chitosan oligosaccharides (COSs) with various molecular weights (MW) were studied for gene transfection agents. MWs of COSs fractionated by ultrafiltration techniques were identified as narrow MW distributions with the average MW ranging from 1 to 10 kDa through gel permeation chromatography (GPC) measurement depending on the applied ultrafiltration membranes. Their structural characterizations were analyzed by FTIR spectrophotometer and $^1H$ NMR. The degree of deacetylation was determined by UV spectroscopy showing the degree of deacetylation above 90%. The relative cell viabilities were maintained over 100% (10 mg/mL), independent of the MW of the fractionated COSs. The fractionated COSs of 10 mg/mL concentration with narrow MW distributions showed non-cytotoxicity in Caco-2 cells.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.450-450
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• 2003

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.452-452
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• 2003

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.301.1-301.1
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.149-150
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• 2003

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.151-152
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• 2001

Chitin, a polymer of N-acetylglucosamine ($\beta$-1,4 linked 2-acetamido-D-glucose), is a cellulose-like biopolymer present richly in the exoskeleton of crustaceans and in cell walls of fungi, insects and yeast. Chitosan is derived from chitin by deacetylation, to different degrees, in the presence of alkali. [l]. Recent studies for chitin and chitosan have been concentrated in bioactivities such as antitumor activity, immuno-enhancing effects, enhancing protective effects against infection with some pathogens in mice, and antimicrobial activeity [2]. (omitted)

• The Korean Journal of Food And Nutrition
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• v.8 no.1
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• pp.43-49
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• 1995

This studies were carried out to purification and seperation of chitooligosaccharides which containing excellent biological active substance. After deacetylation of chitosan (DAC%), DAC-45%, DAC-70%, DAC-95% and DAC-99% were used substrates and hydrolyzed by chitosanase (Bacillus pumilus BN-262) DAC-99% has excellent hydrolyzate which contained several chitooligosaccharides. Therefore, chitosan was hydrolyzed DAC-90 as substrate by chitosanase, and then purified and seperated of chitooligosaccharides Gel filteration and HPLC. This oligosaccharides composed with GlcN0, GlcN2, GlcN3, Glc5 and GlcN6.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.80-87
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• 2008

The 3T3-L1 cell line is a well-established and commonly used in vitro model to assess adipocyte differentiation. Over the course of several days, confluent 3T3-L1 cells can be converted to adipocytes in the presence of an adipogenic cocktail. In this study, the effects of chitosan oligosaccharides (CO) on adipocyte differentiation of 3T3-L1 cells were studied. The CO significantly decreased lipid accumulation, a marker of adipogenesis, in a dose-dependent manner. The low molecular mass CO (1-3 kDa) were the most effective at inhibiting adipocyte differentiation. Moreover, mRNA expression levels of both CCAAT/enhancer-binding protein (C/EBP) ${\alpha}$ and peroxisome proliferator-activated receptor (PPAR) ${\gamma}$, the key adipogenic transcription factors, were markedly decreased by CO treatments. CO also significantly down regulated adipogenic marker proteins such as leptin, adiponectin, and resistin. Our results suggest a role for CO as antiobesity agents by inhibiting adipocyte differentiation mediated through the down regulated expression of adipogenic transcription factors and other specific genes.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.608-611
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• 2000

To separate chitosanoligosaccharides easily by size exclusion, an coencapsulating technology of substrate and enzyme was developed. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The lower limit of the alginate concentration and the agitation speed were 0.5% and 40 rpm, respectively. Membrane thickness and capsules diameter were $10{\mu}m$ and approx. 3.0mm, 1.5mm, respectively. The molecular weight difference by concentration and cps of alginate were of little significance. And also, the molecular weight of distribution according to enzyme concentration was low concentration of enzyme produced high molecular weight of oligosaccharides. At 1.5mm size of capsule, product diffusion rate to outer part was higher than other capsules. The molecular weight distribution of the released oligosaccharides ranged from 1000 to 6000 Da.