REACTIVITY CHARACTERISTICS OF SQUID BETA-CHITIN AS COMPARED WITH THOSE OF SHRIMP CHITIN - HIGH POTENTIALS OF SQUID CHITIN AS A STARTING MATERIAL FOR FACILE CHEMICAL MODIFICATIONS
REACTIVITY CHARACTERISTICS OF SQUID BETA-CHITIN AS COMPARED WITH THOSE OF SHRIMP CHITIN - HIGH POTENTIALS OF SQUID CHITIN AS A STARTING MATERIAL FOR FACILE CHEMICAL MODIFICATIONS
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DOI：
10.1002/pola.1994.080320603
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发表时间：
1994-04-30
影响因子：
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通讯作者：
SHIMODA, K
中科院分区：
文献类型：
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作者：
KURITA, K;ISHII, S;SHIMODA, K
从鱿鱼围栏中分离的β-甲壳素的化学反应性已在各种反应中进行了研究，以阐明以简单的方式进行简易修饰的可能性，从而制备具有明确结构的衍生物。β-甲壳素在普通溶剂如甲醇和吡啶中溶胀，这与普通的α-甲壳素不同，并且表现出比α-甲壳素高得多的反应性。在甲醇溶液中，用乙酸酐将β-甲壳素中的游离氨基选择性地乙酰化，得到结构均匀的甲壳素聚（N-乙酰基-D-氨基葡萄糖）。在吡啶中进行乙酰化反应时，除了N-乙酰化反应外，O-乙酰化反应也顺利进行。以4-二甲氨基吡啶为催化剂，在温和条件下可实现完全乙酰化。甲苯磺酰化在吡啶中也是相当有效的，而没有副反应，如在α-甲壳素的甲苯磺酰化中不可避免的N-脱乙酰化。β-甲壳素还能够在4-二甲基氨基吡啶存在下在吡啶中直接三苯甲基化。所有这些反应与α-甲壳素是相当缓慢的，没有反应或只有非常低程度的取代被观察到，表明高潜力的β-甲壳素作为一个多功能的原料，容易的改性反应。(C)John Wiley & Sons，Inc.
Chemical reactivity of beta-chitin isolated from squid pens has been examined in various reactions to elucidate the possibility of facile modifications in simple manners leading to the preparation of derivatives with well-defined structures. beta-Chitin swelled in common solvents such as methanol and pyridine unlike the ordinary alpha-chitin and exhibited much higher reactivity than alpha-chitin. Free amino groups present in beta-chitin were easily and selectively acetylated with acetic anhydride in methanol to give chitin with a uniform structure, poly(N-acetyl-D-glucosamine). When acetylation reaction was carried out in pyridine, O-acetylation proceeded smoothly besides N-acetylation. In the presence of 4-dimethylaminopyridine as the catalyst, even full acetylation was achieved under mild conditions. Tosylation was also quite efficient in pyridine without side reactions such as N-deacetylation which is unavoidable in the tosylation of alpha-chitin. beta-Chitin also enabled direct tritylation in pyridine in the presence of 4-dimethylaminopyridine. All these reactions were quite sluggish with alpha-chitin, and no reactions or only very low extents of substitution were observed, indicating the high potential of beta-chitin as a versatile starting material for facile modification reactions. (C) 1994 John Wiley & Sons, Inc.