• Journal of Nutrition and Health
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• 제36권9호
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• pp.908-917
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• 2003

It has been proposed that oxidative modification of LDL (oxLDL) plays a significant role in the pathogenicity of atherogenesis. We tested the hypothesis that chitin and chitosan may function as antioxidants with respect to 0.1 mg cholesterol/ml LDL incubated with 5 $\mu$ M Cu$^2$$^{+}$alone or in the P338Dl mouse macrophage system using L-ascorbic acid as a standard classical antioxidant. The degree of oxLDL formation was ascertained by the relative electrophoretic mobility (rEM) in the combination of thiobarbituric acid reactive substances (TBARS) levels, and the cytotoxicity of oxLDL was detected by macrophage viability. The oxLDL uptake and foam cell formation of macrophages were measured by Oil Red O staining. Incubation with Cu$^2$$^{+}$and macrophages increased rEM of LDL and stimulated TBARS formation. Culture of macrophages with LDL in the presence 5 $\mu$ M Cu$^2$$^{+}$induced macrophage death. In cell-free system 200 $\mu$g/ml water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation. Water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation near-completely relative to L-ascorbic acid, whereas water-soluble chitin and chitin-oligosaccharide had no measurable antioxidant effect. In macrophage system water-soluble chitosan and chitosan-oligosaccharide blocked oxidation of LDL with a significant increase in cell viability, and decreased TBARS in medium. As for the inhibitory effect on macrophage foam cell formation, chitosan and its oligosaccharide, but not watersoluble chitin, revealed the effectiveness. The endothelial expression of lectin-like oxLDL receptor-1 (LOX-1) was tested by Western blot analysis, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide blocked LOX-1 expression. These results indicate that water-soluble chitosan and its oligosaccharide showed the inhibitory effect on Cu$^2$$^{+}$-induced LDL oxidation of macrophages, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide had blocking effect on oxLDL receptor expression in the human umbilical vein endothelial system. Thus, water-soluble chitosan and its oligosaccharides possess anti-atherogenic potentials possibly through the inhibition of macrophage LDL oxidation or endothelial oxLDL receptor expression depending on chemical types.l types.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
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• pp.76-80
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• 1997

• Fibers and Polymers
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• 제6권3호
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• pp.219-223
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• 2005

Water-soluble chitin (WSC) was prepared by carefully deacetylating chitins to about $50\%$ of N-acetyl content. Topical formulations based on WSC were prepared and their effects on wound healing were evaluated on a rabbit ear model. Full-thickness, open skin wounds were made on the ears of rabbits and WSC ointments were embedded in the open wounds. The application of WSC ointments significantly accelerated wound healing and wound contraction. The areas of epithelial-ization and granulation tissues in WSC ointment group are remarkably larger than those in control group (no treatment) and in placebo group (treated with ointment-base materials). A large number of grown granulation tissues including dense fibroblast deposition were observed under the thickened epithelium of the wound treated with WSC ointments. The number of inflammatory cells in WSC ointment group was significantly decreased compared with those in control and placebo groups, indicating that WSC would give low stimuli to wounds and prevent excessive scar formation. Neovascularization was the most prominent in WSC ointment group. Wound contraction in WSC ointment group was much larger than those in control and placebo groups. Overall results demonstrate that the topical formulation based on WSC is considered to become an excellent dressing as a wound healing assistant.

• 대한화학회지
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• 제45권4호
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• pp.334-340
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• 2001

CM-chitin은 화장품 분야에서 보습제, 유연제, 피부관리를 위한 세포활성제 및 미백제등으로 다양하게 이용되고 있는 것으로 알려져 있다. 본 연구에서는 CM-chitin제조공정을 기존의 방법에서 몇가지 절차를 배재하여 단순화 하였다. Chitin분말을 NaOH와 혼합하고 16hrs 동안 동결 및 교반을 통해 ClCH2COONa와 isopropyl alcohol혼합액을 첨가하였다. 그 결과 높은 치환도의 CM-chitin을 얻을 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.759-766
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• 2008

Among more than a hundred colonies of fungi isolated from soil samples, DY-52 has been screened as an extracellular chitin deacetylase (CDA) producer. The isolate was further identified as Mortierella sp., based on the morphological properties and the nucleotide sequence of its 18S rRNA gene. The fungus exhibited maximal growth in yeast peptone glucose (YPD) liquid medium containing 2% of glucose at pH 5.0 and $28^{\circ}C$ with 150 rpm. The CDA activity of DY-52 was maximal (20 U/mg) on the 3rd day of culture in the same medium. The CDA was inducible by addition of glucose and chitin. The enzyme contained two isoforms of molecular mass 50 kDa and 59 kDa. This enzyme showed a maximal activity at pH 5.5 and $60^{\circ}C$. In addition, it had a pH stability range of 4.5-8.0 and a temperature stability range of $4-40^{\circ}C$. The enzyme was enhanced in the presence of $Co^{2+}$ and $Ca^{2+}$. Among various substrates tested, WSCT-50 (water-soluble chitin, degree of deacetylation 50%), glycol chitin, and crab chitosan (DD 71-88%) were deacetylated. Moreover, the CDA can handle N-acetylglucosamine oligomers $(GlcNAc)_{2-7}$.

• Applied Biological Chemistry
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• 제35권4호
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• pp.265-271
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• 1992

키틴과 키토산으로부터 carboxymethylchitin, acetylchitin, ethylchitosan, N-acetylchitosan 및 chitosansulfate를 합성하여 그 물리화학적 기능특성을 키틴 및 키토산과 비교 검토 하였다. Carboxymethylchitin은 물과 아세트산에 용해되었지만 ethylchitin은 아세트산에만 용해되었다. 보수력은 N-acetylchitosan이 1194%로 키틴에 비해 약 2배 정도 높았으며, 지방흡수력은 carboxymethylchitin이 1800%로 키틴 511%에 비해 월등히 높았다. Carboxymethylchitin의 유화성이 75.91%로 가장 높았으며 그 다음이 미세결정형 키틴으로 57.02%였으나 키틴 및 키토산은 유화성이 나타나지 않았다. 색소흡착능은 acetylchitin이 0.93 mg dye/g sample(Blue R-250), 0.96 mg dye/g sample(Red-2)로 키틴 및 키토산 보다 높았다. 따라서 carboxymethylchitin은 유화제로서, acetylchitosan은 색소흡착제로서 이용이 가능할 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.43-46
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• 1995

For using additives of foods, or cosmetics, a strain A80 producing blue pigment was isolated from soil. The strain A80 was identified as a strain of Azotobacter vinelandii based on morphological and physiological characteristics. The strain A80 was extracellulaly secreted the blue pigment on PYG agar plate, but not secreted it into PYG broth. And then, the strain A80 was extracellulaly secreted the blue pigment in PYG broth containing 2.0% chitin, while the strain A80 was not secreted the blue pigment in PYG broth containing 2.0% chitin and 1% NaCl simultaniously.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1999년도 봄 학술발표회 논문집
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• pp.28-31
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• 1999

• 한국응용과학기술학회지
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• 제13권2호
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• pp.85-92
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• 1996

Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chitosan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from water-soluble chitosan of average molecular weight ranging $9,000{\sim}120,000$ was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperture goes higer in temperture range of $15^{\circ}C{\sim}45^{\circ}C$. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.

• 대한핵의학회지
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• 제32권4호
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• pp.391-395
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• 1998

목적 : 방사성스트론튬은 핵사고시 방사성옥소, 방사성세슘 등과 더불어 환경 중으로 다량이 방출되어 환경 및 인체를 오염시키는 방사독소 중의 하나이다. 본 실험에서는 분자량이 서로 다른 카이틴 3종, 카이토산 3종, 인산카이토산 1종 등의 천연착화제와 EDTA, DTPA 등의 화학적착화제를 컬럼크로마토그래피 방법을 통해 방사성스트론튬에 대한 착화율을 비교하였다. 대상 및 방법: 실험에 사용한 카이틴 및 카이토산, 인산카이토산, EDTA, DTPA은 모두 수용성으로 생리식염수에 녹여 0.01% 상태로 만들어 사용하였으며, 컬럼은 PD-10 Sephadex G-25 M을 사용하였다. 착화물 형성비율은 전체 분획의 방사능 중 착화물의 분획이 차지하는 비율(%)로 산출하였다. 결과: 카이틴, 카이토산, 인산카이토산과 같은 천연착화제나 EDTA, DTPA 등의 화학적착화제 모두 pH 3, 5, 7에서 평균 90% 이상의 높은 착화율을 나타내었는데, 통계적으로 유의한 차이는 없었다. 결론: 천연착화제인 카이틴, 카이토산은 화학적착화제와 차이가 없이 방사성스트론튬에 대해 우수한 착화율을 보이므로, 무독성인 점을 감안한다면 방사성스트론튬 오염에 실제적으로 사용할 수 있는 착화제라고 사료된다.