Direct prediction of residual dipolar couplings of small molecules in a stretched gel by stochastic molecular dynamics simulations
Direct prediction of residual dipolar couplings of small molecules in a stretched gel by stochastic molecular dynamics simulations
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DOI：
10.1002/mrc.4181
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发表时间：
2015-03-01
影响因子：
2
通讯作者：
Luy, Burkhard
中科院分区：
文献类型：
--
作者：
Frank, Andreas O.;Freudenberger, J. Christoph;Luy, Burkhard
残余偶极耦合是非常有用的核磁共振参数计算和细化分子结构，动力学和相互作用。然而，对于某些应用，不可避免的是，分子在取向介质中的首选取向是先验计算的。已经发展了几种预测分子取向和残余偶极偶联的方法。这种方法有利于大分子和特定的小分子应用，但对大量有机化合物缺乏足够的准确性，因为这些有机化合物必须考虑所有相关分子的精细结构和最终的灵活性，或者仅限于特定的、经过充分研究的液晶。我们介绍了一个简化的模型，用于详细的全原子分子动力学计算，其中聚合物链沿着主轴排列，作为模拟聚合物基凝胶型排列介质中中小溶质的首选取向的新方法。正如第一个在聚苯乙烯/CDCl3凝胶中的士的宁的例子所显示的那样，考虑到结构细节和聚合物和溶质的动态平均效应，模拟可能能够准确预测残余的偶极偶联。版权所有：John Wiley & Sons， Ltd
Residual dipolar couplings are highly useful NMR parameters for calculating and refining molecular structures, dynamics, and interactions. For some applications, however, it is inevitable that the preferred orientation of a molecule in an alignment medium is calculated a priori. Several methods have been developed to predict molecular orientations and residual dipolar couplings. Being beneficial for macromolecules and selected small-molecule applications, such approaches lack sufficient accuracy for a large number of organic compounds for which the fine structure and eventually the flexibility of all involved molecules have to be considered or are limited to specific, well-studied liquid crystals. We introduce a simplified model for detailed all-atom molecular dynamics calculations with a polymer strand lined up along the principal axis as a new approach to simulate the preferred orientation of small to medium-sized solutes in polymer-based, gel-type alignment media. As is shown by a first example of strychnine in a polystyrene/CDCl3 gel, the simulations potentially enable the accurate prediction of residual dipolar couplings taking into account structural details and dynamic averaging effects of both the polymer and the solute. Copyright (c) 2015 John Wiley & Sons, Ltd.