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本文利用表面张力、粘度、电子吸收光谱、电导和旋光谱等方法,研究了在二甲基亚砜(DMSO)-水混合溶剂中糖淀粉的大分子构象及其与极性探针——N-乙基-4-十六烷氧羰基-吡啶盐碘化物(1)相互作用而形成螺旋包结结合物的结果。文中指出,随溶剂DMSO含量的减少,糖淀粉分子构象从僵直链的规整螺旋转变至由无规线团区连结的松弛和扩展的螺旋,伴随着粘度和旋光谱的明显变化。糖淀粉与1的相互作用机制随溶剂组成变化而不同。当溶剂中DMSO的体积分数Φ_(DMSO)在大于0.70左右的区域时,作用方式类似于偶氮染料,是缔合定位于螺旋区的外围;小于此区域,则受物进入螺旋内穴而形成螺旋包结络合物,旋光谱的研究结果表明此时受物1在其紫外吸收峰位置出现新的负Cotton效应,即处在高手征性环境中的非手征性受物1被诱导出不对称性。由表面张力-浓度曲线,电导等方法测定的包结络合平衡数据给出,特性解离常数K_d~*与溶剂组成关系极大,包结驱动力系自本体相转移至非极性相的疏水-亲脂相互作用,得出的最大包结部位数小于30,也支持了形成螺旋包结物的结论。
In this paper, the macromolecule conformations of glycans in dimethylsulfoxide (DMSO) -water mixed solvent and their interaction with polar probe-N were investigated by means of surface tension, viscosity, electron absorption spectroscopy, - ethyl-4-hexadecyloxycarbonyl-pyridinium iodide (1) to form a helical inclusion complex. It is pointed out that with the decreasing of DMSO content, the molecular conformation of glycosylated starch changes from the regular helical chain of rigid chain to the relaxed and extended helix linked by random coil region with the obvious change of viscosity and optical spectrum. The mechanism of the interaction between sugar and starch varies with the composition of the solvent. When the concentration of DMSO in the solvent is greater than 0.70, the mode of action is similar to that of azo dyes, and the association is located at the periphery of the helical region. If the concentration is smaller than this region, the acceptor enters the helical pocket and forms The results of spin-coil complex and spin-spectrum study show that Reagent 1 has a new negative Cotton effect at its UV absorption peak, that is, the non-chiral Receptor 1 in high-chiral environment is induced Asymmetry. The complexation equilibrium data obtained from the method of surface tension-concentration curve and conductance show that the characteristic dissociation constant K_d ~ * has a great relationship with the solvent composition. The entrapment driving force is transferred from the bulk to the non-polar phase Hydrophobic - lipophilic interactions, the maximum number of inclusion sites obtained less than 30, also supported the formation of spiral inclusion conclusion.