キトサン

化学的特性キトサンはクラゲやキノコなど自然界に広く存在する物質で特に甲殻類の外骨格に多く含まれていますこの天然ポリマーはキチンから化学的に作られキチンが持つアセチル基を一部または全部除去することで得られますその生物学的および化学的性質からキトサンは様々な産業で利用されています

化学的特性Chitosan occurs as odorless, white or creamy-white powder or flakes. Fiber formation is quite common during precipitation and the chitosan may look ‘cottonlike’.

化学性质キチンの側鎖のアセチル基を加水分解したもの

解説キトサン,グルコースの誘導体であるNアセチルDグルコサミンの重合体で，化学構造がセルロースに似た多糖類をキチンといい，その脱アセチル化物をキトサンという。カニ，エビなどの甲殻類や昆虫の外皮，菌類の細胞壁の主要な構成成分で.

用途写真乳剤,合成繊維や織物の染色,広範囲の重金属吸着剤, 各種酸性物質(核酸,エンドトキシンなど)の除去剤、カチオン系活性汚泥凝集剤、植物の生長促進剤。

用途各種凝集剤

天然物の起源Chitosan comes from the shell of marine crustaceans.

使用Forms gels with multivalent anions. Gives clear solutions that dry to strong, clear films.Flocculant, protein precipitation, encapsulating agent and aqueous thickener.Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application.Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

一般的な説明Chitosan is a linear amino polysaccharide composed of approximately 20% β1,4-linked N-acetyl-D-glucosamine (GlcNAc) and approximately 80% β1,4-linked D-glucosamine (GlcN) that is prepared by the partial deacetylation of chitin in hot alkali.

Chitosan is manufactured commercially by chemically treating the shells of crustaceans such as shrimps and crabs. The basic manufacturing process involves the removal of proteins by treatment with alkali and of minerals such as calcium carbonate and calcium phosphate by treatment with acid. Before these treatments, the shells are ground to make them more accessible. The shells are initially deproteinized by treatment with an aqueous sodium hydroxide 3–5% solution. The resulting product is neutralized and calcium is removed by treatment with an aqueous hydrochloric acid 3–5% solution at room temperature to precipitate chitin. The chitin is dried so that it can be stored as a stable intermediate for deacetylation to chitosan at a later stage. NDeacetylation of chitin is achieved by treatment with an aqueous sodium hydroxide 40–45% solution at elevated temperature (1108℃), and the precipitate is washed with water. The crude sample is dissolved in acetic acid 2% and the insoluble material is removed. The resulting clear supernatant solution is neutralized with aqueous sodium hydroxide solution to give a purified white precipitate of chitosan. The product can then be further purified and ground to a fine uniform powder or granules. The animals from which chitosan is derived must fulfil the requirements for the health of animals suitable for human consumption to the satisfaction of the competent authority. The method of production must consider inactivation or removal of any contamination by viruses or other infectious agents.

合成方法濃アルカリでキチンを処理する