| Project/Area Number |
10650871
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子合成
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| Research Institution | Seikei University |
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Principal Investigator |
KURITA Keisuke Fac.of Engineering, Seikei University, Professor, 工学部, 教授 (30102180)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIYAMA Yasuhiro Fac.of Engineering, Seikei University, Assoc. Professor, 工学部, 助教授 (30286900)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Chitin / Chemical Modification / Branched Polysaccharide / Functional Polysaccharide Silylation / Glycosylation / Antimicrobial activity / Biodegradability / 生分解性 / 分枝型多糖 / キトサン / 分岐型多糖 / シリル化キチン / 反応前駆体 / 金属イオン吸着能 |
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| Research Abstract |
Although chitin is an unutilized biomass resource, it is quite attractive as a specialty functional biopolymer owing to its distinctive biological activities as well as unique physicochemical properties, Our interest has been focused on the development of efficient chemical modifications of chitin so as to make possible construction of sophisticated molecular environments leading to the synthesis of polymeric materials with advanced functions.
A series of regioselective modification reactions of chitosan gave a derivative with a reactive group only at C-6, which was glycosylated with an oxazoline derived from glucosamine to introduce sugar branches. The degree of substitution was up to 0.6. The resulting branched chitin and chitosan were soluble in water and exhibited significant antimicrobial activity. They were degraded enzymatically, and the rate was dependent on the degree of substitution. Maltose also could be introduced using an orthoester of the disaccharide. Comb-shaped chitosan derivatives were prepared by reductive alkylation of aldehydes of poly (ethylene glycol); they were soluble and adsorbed metal cations.
In order to synthesize branched polysaccharides in a simple manner, trimethylsilylated chitin was prepared and evaluated as an organosoluble precursor for efficient modifications. Trimethylsilylation was more facile with β-chitin than α-chitin, and a fully silylated derivative was obtained. The silylated chitin was readily soluble in common organic solvents, and chitin films were easily prepared by casting and subsequent desilylation. It exhibited considerable reactivity in solution as confirmed by tritylation and glycosylation. The degrees of substitution for these reactions were 1.0 and 0.6, respectively, under appropriate conditions. Trimethylsilylated chitin has thus proved to be a superb precursor for modification reactions to allow synthesis of various derivatives from chitin.
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