Positional Variance in NMR Crystallography
Positional Variance in NMR Crystallography
复制标题
DOI：
10.1021/jacs.6b12705
复制
发表时间：
2017-02-22
影响因子：
15
通讯作者：
Emsley, Lyndon
中科院分区：
文献类型：
--
作者：
Hofstetter, Albert;Emsley, Lyndon
我们提出了一种方法来定量的位置不确定性晶体结构确定的化学位移为基础的核磁共振结晶学。该方法结合了分子动力学模拟和密度泛函理论计算以及实验和计算化学位移的不确定性。通过这种方式，我们得到了由核磁共振结晶学确定的晶体结构中每个原子的平均位置精度以及各向同性和各向异性位置精度。对可卡因、氟他胺、氟芬那酸、青霉素G的K盐和药物4-[4-(2-adamantylcarbamoyl)-5-tert-butylpyrazol-1-yl]benzoic酸(AZD8329)的4种形式的晶体结构进行了研究。我们发现，对于可卡因的晶体结构，不确定度对应于位置RMSD为0.17埃。这比基于单晶X射线衍射法的结构测定低2.5倍。
We propose a method to quantify positional uncertainties in crystal structures determined by chemical-shift-based NMR crystallography. The method combines molecular dynamics simulations and density functional theory calculations with experimental and computational chemical shift uncertainties. In this manner we find the average positional accuracy as well as the isotropic and anisotropic positional accuracy associated with each atom in a crystal structure determined by NMR crystallography. The approach is demonstrated on the crystal structures of cocaine, flutamide, flufenamic acid, the K salt of penicillin G, and form 4 of the drug 4-[4-(2-adamantylcarbamoyl)-5-tert-butylpyrazol-1-yl]benzoic acid (AZD8329). We find that, for the crystal structure of cocaine, the uncertainty corresponds to a positional RMSD of 0.17 angstrom. This is a factor of 2.5 less than for single-crystal X-ray-diffraction-based structure determination.