糖鎖による超分子中の水の運動性及び水素結合特性の磁気共鳴法による検出と応用研究

1.水与多糖动态及相互作用检测体系的构建：(1)将固体回波法检测极短T2(&gt；10μS)与常用的CPMG法相结合，评价了冻水(原来的自由水)和非冻水(部分水合水)的含量、聚合物链上惰性质子与不稳定质子的区别，以及多糖的水化性质。(2)利用脉冲场梯度SE或STE的高场梯度进行扩散测量，和/或利用核磁共振显微成像进行可视化，构建了聚合物和水化水慢运动检测系统。(3)T2和扩散系数的同时分析系统：改进了扩散测量的脉冲序列，使样品中的物种分数保持恒定。(4)存在化学质子交换和扩散分子交换时T_2随温度变化的理论处理：对水质子磁化强度随时间变化的微分方程组进行了数值分析，得到了实验条件下T_2随温度变化的可能性。普鲁兰多糖浓缩液中水的迁移率：利用所建立的体系1(1)和(3)，可以区分-11μ处的冷冻水(T2 10μS)、未冻水(T2 100℃S)和惰性聚合物质子(T2 1ms)，而在温度大于0℃的情况下，通过快速扩散分子交换没有区分水合水和自由水。证明了普鲁兰聚糖链在水溶液中的柔韧性。用电子顺磁共振方法分析了结冷胶对二价阳离子的吸附机理，从分子水平上阐明了结冷胶对二价阳离子的吸附机理。用1HT2核磁共振、圆二色谱和粘弹性等方法研究了明胶凝胶化过程的动力学。证明了在线圈形成之前存在氢键休眠。

1. Construction of the detection system for evaluating the dynamics and interactions of water and polysaccharides : (1) Solid echo method for detecting very short T2 (>l0μs) was combined to the usually used CPMG method to evaluate the amount of frozen water (originally free water) and un-frozen water (a portion of hydration water), differentiation between the inert protons and the labile protons in the polymer chain, and hydration properties of polysaccharides. (2) System for detecting slow motion of polymer and hydration water was constructed employing high field gradient for diffusion measurement due to the pulsed field gradient SE or STE and/or NMR microimaging for visualization. (3) Simultaneous analyzing system of T2 and Diffusion coefficient : Pulse sequence for diffusion measurement was modified to keep the fractions of species in samples constant. (4) Theoretical treatment of temperature dependence of T2 in the presence of a chemical proton exchange and a diffusive molecular exchange : differential equations for time dependence of magnetization due to water proton were numerically analyzed to obtain possible change of T2 with the temperature change under the experimental conditions.2. Water mobility in concentrated pullulan solutions : By using the established systenn 1 (1) and(3), frozen water (T2 10μs), unfrozen water (T2 100μs) and inert polymer protons (T2 1ms) at -11℃ were distinguished each other and in the temperature more than 0℃ hydration water and free water was not differentiate by rapid diffusive molecular exchange. The flexibility of pullulan chain in aqueous solution is proved.3. Uptake mechanism of divalent cation by gellan gum was analyzed by Cu(II) EPR method and the mechanisn was made clear in the molecular level.4. Kinetic studies of the gelation process of gelatin was investigated based on ^1H T_2 NMR, CD and viscoelesticity measurements. Hydrogen bonding dormation in prior to the coil formation was proved.