Clemens-Schöpf-Institut für Organische Chemie und Biochemie, Technical University of Darmstadt, Alarich-Weiss-Str. 16, 64287, Darmstadt, Germany.
Chemistry. 2020 Jun 23;26(35):7831-7839. doi: 10.1002/chem.201905447. Epub 2020 May 28.
Residual dipolar couplings (RDCs) offer additional information for structure elucidation by NMR spectroscopy. They are measured in anisotropic media, such as lyotropic liquid crystalline phases of polypeptides. Today, some suitable polypeptides are known. Nevertheless, structural influences of these polypeptides on the alignment properties are not really understood. Thus, which influence a chiral side chain has on enantiodiscrimination and whether we can improve the enantiodifferentiation significantly by adding an additional chiral center in the side chain are questions of interest. Therefore, new diastereomeric polypeptide-based alignment media with an additional chiral center in the side chain derived from perillyl alcohol were synthesized and their properties were investigated (secondary structure, liquid crystallinity, etc.). The enantiomers of isopinocampheol and β-pinene were used as model analytes for the study of enantiodiscrimination. Additionally, the usage of H- H-RDCs to improve the alignment tensor quality is demonstrated.
残偶偶极耦合(RDC)通过 NMR 光谱为结构阐明提供了附加信息。它们在各向异性介质中进行测量,例如多肽的溶致液晶相。如今,已经有一些合适的多肽被发现。然而,这些多肽对取向性质的结构影响还没有被真正理解。因此,手性侧链的影响,对对映体选择性的影响,以及我们是否可以通过在侧链中添加额外的手性中心来显著提高对映体的区分,都是感兴趣的问题。因此,合成了具有来源于紫苏醇的侧链中的额外手性中心的新的非对映异构体的基于多肽的取向介质,并研究了它们的性质(二级结构,液晶性等)。异缬草酸和β-蒎烯的对映体被用作对映体选择性研究的模型分析物。此外,还证明了使用 H-H-RDC 来改善取向张量质量。