鱿鱼顶骨β-甲壳素的化学反应活性及其与α-甲壳素的比较  

Chemical Reactivity Characteristics of β-Chitin from Squid Pen and Its Comparison with α-Chitin

作　　者：董炎明[1] 阮永红[1] 吴玉松[1] 王勉[1] 丘蔚碧[1] 许聪义[1] 

机构地区：[1]厦门大学材料科学与工程系固体表面物理化学国家重点实验室,厦门361005

出　　处：《高等学校化学学报》2002年第3期490-495,共6页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 99740 2 3 );福建省自然科学基金 (批准号 :E9910 0 0 6)资助

摘　　要：研究了由鱿鱼顶骨提取的β-甲壳素和β-壳聚糖分别对 O-丙酰化 (非均相反应 )和 N-乙酰化 (均相反应 )的反应活性 ,并与 α-甲壳素 /壳聚糖进行了比较 .结果表明 ,β-甲壳素的反应活性比 α-甲壳素差 .β-甲壳素经水磨微纤化后 ,丙酰化反应活性虽然显著提高 ,但仍低于 α-甲壳素 .本文用偏光显微镜和电子显微镜首次观察到微纤化的 β-甲壳素中可以分辨出 4个层次的纤维状结构 ,它们分别是微纤束、微纤、细微纤和原纤 ,直径分别为 1 0 1 ,1 0 0 ,1 0 - 1 和 1 0 - 2 μm数量级 .由于暴露出各层次微纤上更多的自由羟基 。Being different from the literature results, the chemical reactivity of \%β\%\|chitin was found to be poorer than that of \%α\%\|chitin for O\|propionylation reaction(basically a heterogeneous reaction). But the chemical reactivity of \%β\%\|chitin was almost the same as that of \%α\%\|chitin for N\|acetylation reaction(a homogeneous reaction). The poor reactivity of \%β\%\|chitin is explained by the higher crystallinity shown by the results of X\|ray diffraction, the closer fibrillar structure shown by microscopy, and the higher stability of crystals shown by higher decomposition temperature in the thermogravimetric curves. After \%β\%\|chitin was fibrillated by wet grinding, the O\|propionylation reactivity increases evidently, but was still lower than that of \%α\%\|chitin. Four levels of fibril structure can be distinguished in fibrillated \%β\%\|chitin by polarized optical microscopy and scanning electron microscopy, \%i.e.\% fibrillar bundle, fibril, microfibril and elementary fibril with diameter in the order of 10\+1, 10\+0, 10\+\{-1\} and 10\+\{-2\} μm respectively. A model for four levels of fibril structure of \%β\%\|chitin is first suggested. Because more free hydroxyl groups are exposed on all levels of fibrils, the chemical reactivity of fibrillated \%β\%\|chitin enhances.

关 键 词：甲壳素 壳聚糖 β-甲壳素 化学反应活性 α-甲壳素 鱿鱼顶骨 结构 

分 类 号：Q539[生物学—生物化学] O636.1[理学—高分子化学]