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化学学报
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化学学报 ›› 1981, Vol. 39 ›› Issue (4): 309-318. 上一篇    下一篇

论文

螺旋构象的微环境效应——1.羧甲基糖淀粉钠对具有疏水性长链烷基的受物的包结作用

惠永正, 顾建华   

  1. 中国科学院上海有机化学研究所
  • 投稿日期:1980-02-01 发布日期:2013-06-03

THE MICROENVIRONMENTAL EFFECTS OF THE HELICAL CONFORMATIONS OF AMYLOSE AND ITS DERIVATIVES 1. THE INCLUSION OF THE SUBSTRATES CARRYING A HYDROPHOBIC LONG HYDROCARBON CHAIN WITH SODIUM CARBOXYMETHYLAMYLOSE AS THE HOST

HUI YONG-ZHENG, GU JIAN-HUA   

  1. Shanghai Institute of Organic Chemistry, Academia Sinica
  • Received:1980-02-01 Published:2013-06-03

PDF

787

被引次数

47

本文报道了具有类似环葡萄糖疏水内穴特性但长度及内穴尺寸为可变化的羧甲基糖淀粉钠(Na-CMA)螺旋构象对具有长链烷基的受物:十六烷基三甲基氯化铵(CTACl)、十二烷基三甲基碘化铵(LTAI)和十二烷基硫酸钠(NaLS)的包结作用.使用表面张力法求得Na-CMA—CTACl包结常数在1.27～2.30×104M-1左右,Na-CMA—LTAI为0.52×103M-1,Na-CMA—NaLS为0.73×103M-1,表明与阴或阳离子的受物均可形成稳定包结络合物,稳定程度由受物烃链疏水性决定.Na-CMA的最大结合部位对于CTACl,LTAI,NaLS分别为7.7,9.8,10与形成6-螺旋和受物分子相对长度推算出的数值很接近.从Na-CMA—CTACl包结常数与温度的关系求得包结过程的热力学参数为ΔG298=-5.7kcal/mol,ΔH298=3.5kcal/mol,ΔS298=7.6 e.u..说明包结驱动力不同于典型疏水作用的熵控制和环葡萄糖包结的焓控制机制.根据粘度和表面张力的测定提出了这种包结过程伴随着Na-CMA链从紧密线团至间断螺旋的构象变化,反映出Na-CMA与环葡萄糖不同的特性,看来更适合于作为生物大分子识别受物的模型.

The use of cyclodextrin as host to provide a special environment for organic reactions and for enzyme models has received considerable attention in recent years. However, in cyclodextrin both the size and length of the hydrophobic cavity are fixed. In this paper, another type of inclusion with sodium carboxymethylamylose (Na-CMA) playing the role of the host which provides a cavity with the characteristics similar to that of cyclodextrin but with more flexibility in itg size and length was described. The substrates with hydrophobic long hydrocarbon chain used were: cetyltrimethylammonium chloride (CTACl);lauryltrimethylammonium iodide (LTAI) and sodium laurylsulfate (NaLS).