Direct prediction of residual dipolar couplings of small molecules in a stretched gel by stochastic molecular dynamics simulations

Autor: Andreas O, Frank, J Christoph, Freudenberger, Alexey K, Shaytan, Horst, Kessler, Burkhard, Luy
Rok vydání: 2014
Předmět:
Zdroj: Magnetic resonance in chemistry : MRC. 53(3)
ISSN: 1097-458X
Popis: 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.
Databáze: OpenAIRE
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