• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.791-795
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• 1996

Toha-jeot(salt-fermented Toha shrimp) is a traditional fermented food in Korea. Toha-jeot is fermented for 90 days at $4\pm1^{\circ}C$ with 20%(w/w) salt per live Toha shrimp. We expect that the high polymer chitin of Toha shell will be hydrolyzed by chitinase during the fermentation of Toha-jeot and that the low molecular weight of chitin oligosaccharides will be produced. We experimented 7 samples which were taken at the interval of 15 days during the total 90 days of fermentation. We also measured molecular weight of Toha-chitin, viscosity and molecular weight distribution of chitin during fermentation of Toha-jeot, The decrease of viscosity and average molecular weight of chitin were observed as fermentation proceeds. Chitin oligosaccharide with $10^3molecular$ weight was low until 60 days fer-mentation. However, chitin oligosaccharide with $10^3molecular$ weight was high after 75 days fer-mentation. And chitin oligosaccharide with $10^2molecular$ weight were observed after fermenting Toha for 75 days and 90 days, but chitin oligosaccharide with 10'molecular weight did not appear up to 60 days of fermentation.ation.

• Journal of Life Science
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• v.7 no.2
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• pp.149-159
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• 1997

Chitin, a linked polysaccharide composed of 2-acetamido-2-deoxy-$\beta$-D-glucopytanose residues, is distributed widely in nature. It has been utilized on various application field due to the development of chitin derivatives such as chitosan, partial deacetylated chitin, carboxylmethyl chitin, sulfated chitin, and so on. Chitin and chitosan have been recently interested in antitumor and antimicrobial activities, because of a powerful tumor inhibitory effect against experimental mouse tumors. Especially, the oligosaccharides obtained by partial degradation of them exhibited a remarkable antitumor effect against sarcoma 180, MM 48 and Meth Asolid tumors and antimetastatic effect against Lewis lung carcinoma in mice. This review describes on antitumor effects of chitin, chitosan and their oligosaccharides by their mechanism of action involving enhancement of immunological system.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.221-224
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• 1998

Toha-jeot, salt-fermented Toha shirmp(caridina denticulata denticulata DeHAAN) is a traditional fermented food in Korea. Samples of Toha-jeot used in the present study were a low-salt group of 15% sodium chloride(L), a high-salt group of 23% sodium chloride(H), a 50% conventional soybean sauce group(S), a low-salt group contraining 2% wheat bran (W2%-L) , a high -salt group containing 2% wheat bran(W2%-H), a low-salt group containing 4% wheat bran(W4%-L)and a high-salt group containing 4% wheat bran (W4%-H). These seven groups were refrigerated at 4 $\pm$1$^{\circ}C$ and then taken out for analysis at theree month intervals. We investigated the functional components of Toha-jeot during fermentation . Long fermentation of Toha-jeot lowered the viscosity of chitin and tended to reduce the distribution of molecular weight. THe formation of chitin oligosaccharides on the other hand, increased significantly. After nine months of fermenttion, chitin oligosaccharides(M.W. 823~1789) constituting 24.75% of Toha chitin were produced in the sample of W2%-H. During the same period, chitin oligosaccharides(M.W.1436-1879) constituting 66.30% of Toha chitin were produced in the samples of S. However, chitin oligosaccharides were not produced in Jeotsaeu-jeot made of sea-water shrimp when fermented for six months.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.416-417
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• 2000

Chitin, a poly $\beta$-(1longrightarrow14)-N-acetyl-D-glucosamine, is best known as a cell wall component of fungi and as a skeletal materials of invertebrates. Chitosan is derived from chitin by deacetylation in the presence of alkali. Chitosan has been developed as new physiological materials since it possesses antibacterial activity, hypocholesterolemic activity and antihypertensive action. However, the actions of chitosan in vivo still remain ambiguous as the physiological functional properties because most animal intestines, especially the human gastrointestinal tract, do not possess enzyme such as chitosanase which directly degrade the $\beta$-glucosidic linkage in chitosan, and consequently the unbroken polymers may be poorly absorbed into the human intestine. Therefore, recent studies as chitosan have attracted interest for chitosan oligosaccharides, because the oligosaccharides process not only water-soluble property but also versatile functional properties such as antitumor activity, immune-enhancing effects, enhancement of protective effects against infection with some pathogens in mice and antimicrobial activity (Kingsnorth et al., 1983, Mori et al., 1997). (omitted)

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.277-283
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• 1994

An antimicrobial chitinase was purified from grapefruit extract and its properties were characterized. The chitinase was purified with a single step chromatography on regenerated chitin affinity gel column. The molecular weight of the purified chitinase was 29 kDa. The grapefruit extract contained the chitinase protein more than 50% of its total soluble proteins measured by coomassie stained protein bands. When the purified chitinase was incubated with polymers of N-acetylglucosamine (NAG), such as mycelia of Fusarium oxysproum and swollen chitin, they were degraded to oligosaccharides, and the oligosaccharides were then further hydrolyzed by the same enzyme to monomer and dimer of NAG. This result suggests that the chitinase contained both endo- and exo- chitinase activities. The chitinase was stable to heat and pH treatment; its activity was not diminished by the heat treatment upto 7$0^{\circ}C$ for 1 hr, and it showed a pH stability in the range of pH 4.0 to 12.0.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.187-188
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• 2002

Chitosan is a natural biopolymer of N-acetylglucosamine (-1,4 linked 2-acetamido-D-glucose), which is obtained after alkaline deacetylation of the chitin derived from the cell walls of lower plants and in the skeletal tissues of lower animals including arthropods and mollusks. In the recent studies, chitin and chitosan have attracted interest for converting them to oligosaccharides because the oligosaccharides are not only water-soluble but also possess versatile functional properties such as antimicobial activity (Jeon and Kim, 2000; Jeon et al., 2001). (omitted)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.241-242
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• 2001

Chitosan, a deacetylated derivative of chitin, is one of the abundant resources, and its biological properties such as antibactierial activity, hypocholesterolemic activity, and hypertensive action are remarked. However, increasing attention has recently been yen to converting chitosan to its oligosaccharides because they possess various functional properties like antitumor activity, immune-enhancing effects, enhancing protective effects against infection with some pathogens in mice, antifungal activity, and antimicrobial activity (Jeon et al., 2001). (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 1997.05a
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• pp.20-27
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• 1997

Chinin is the second most plentiful natural polymer. Currently, chitin and chitosan are manufactured commercially in large scale from crab and shrimp shell as fish processing waste. They is being used in many commercial application because of their various functional properties. Chitosan, in particular, is being evaluated as biomedical materials in a number of food and pharmaceutical industries. Despite their potential abilities, the perfect safety had been demonstrated until now. However, the long-term feeding with chitin was not any negative effect the body weights and serum enzymatic activities in mice. And, in rats supplied with $5\%$ of chitosan diet for 450 days, there was no changes of Ca concentration in blood, bone and other organs except for in muscle. Consequently, there was no direct toxicity of chitin and chitosan against some animals such as rat and mouse by recently reports.

• 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)

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.246-249
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• 2000

We investigated the production of chitin oligosaccharides using food grade papain. A solution of commercial food grade papain (FGP) was dialyzed for 12 h before measuring its chitinolytic activity. The effects of enzyme concentration, reaction temperature, and pH on the endochitinase and $\beta$-N-acetylglucosaminidase activities and the thermostability of these enzymes were investigated. In adddition, the reaction products were analyzed with gel filtration on a Bio-Gel P2. The endochitinase activity was twentyfold higher than that of $\beta$-N-acetylglucosaminidase. The optimal endochitinase activity was at pH 3.0, while the maximal $\beta$-N-acetylglucosaminidase activity was at pH 6.0. The reaction product consisted mainly of the dimer of N -acetylglucosamine, with a small amount of its trimer. Under the experimental conditions, $120{\mu}g$ of chitin oligomers were obtained with 1 mg of FGP protein after an incubation of 2 h.