Departamento de Química Fundamental, Universidade Federal de Pernambuco, Avenida Professor Moraes Rego, 1235, Cidade Universitária, 50670-901, Recife, Pernambuco, Brazil.
Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Fassberg 11, Göttingen, 37077, Germany.
Magn Reson Chem. 2018 May;56(5):321-328. doi: 10.1002/mrc.4711. Epub 2018 Feb 8.
Mechanical compression of polymer gels provides a simple way for the measurement of residual chemical shift anisotropies, which then can be employed, on its own, or in combination with residual dipolar couplings, for structural elucidation purposes. Residual chemical shift anisotropies measured using compression devices needed a posteriori correction to account for the increase of the polymer to solvent ratio inside the swollen gel. This correction has been cast before in terms of a single-free parameter which, as shown here, can be simultaneously optimized along with the components of the alignment tensor while still retaining discriminating power of the different relative configurations as illustrated in the stereochemical analysis of α-santonin and 10-epi-8-deoxycumambrin B.
机械压缩聚合物凝胶为测量残余各向异性化学位移提供了一种简单的方法，该方法可单独使用，也可与残余偶极耦合一起用于结构解析目的。使用压缩设备测量的残余各向异性化学位移需要事后校正，以考虑溶胀凝胶内聚合物与溶剂比例的增加。在此之前，已经根据单个自由参数来表示这种校正，正如这里所示，该参数可以与取向张量的分量一起同时进行优化，同时仍然保持不同相对构型的辨别能力，如 α-山道年和 10-表-8-去氧坎巴亭 B 的立体化学分析所示。
