Chiral Diaminopyrrolic Receptors for Selective Recognition of Mannosides, Part 2: A 3D View of the Recognition Modes by X-ray, NMR Spectroscopy, and Molecular Modeling
Chiral Diaminopyrrolic Receptors for Selective Recognition of Mannosides, Part 2: A 3D View of the Recognition Modes by X-ray, NMR Spectroscopy, and Molecular Modeling
复制标题
DOI：
10.1002/chem.201002872
复制
发表时间：
2011-04-01
影响因子：
4.3
通讯作者：
Roelens, Stefano
中科院分区：
文献类型：
--
作者：
Arda, Ana;Javier Canada, F.;Roelens, Stefano
辛基α-和β-甘露糖苷与新一代手性三足二氨基吡咯受体的一些成员，即（R）-5和（S）-和（R）-7的一组代表性的五种复合物的结构特征，已经通过结合X射线、NMR光谱和分子模拟方法在溶液和固体状态下进行了研究。在固态下，游离受体7的结合臂界定了一个裂缝，其中两个溶剂分子与吡咯基团和苯骨架氢键合。在极性溶剂（CD 3CN）中，化学位移和分子间NOE数据，辅助分子模拟计算，确定这些复合物的受体和糖苷之间的相互作用的结合模式。虽然发现一个单一的结合模式，以充分描述的复合物的无环受体5与α-甘露糖苷，为复合物的环状受体7需要两种不同的结合模式，同时适合所有的实验数据。在所有情况下，通过氢键和CH-pi相互作用的广泛结合是在相同溶剂中测量的亲和力的原因。此外，结合模式密切帐户的识别偏好观察到的异头糖苷和手性受体所表现出的特有的antireosecrimination性能。
The structural features of a representative set of five complexes of octyl alpha- and beta-mannosides with some members of a new generation of chiral tripodal diaminopyrrolic receptors, namely, (R)-5 and (S)- and (R)-7, have been investigated in solution and in the solid state by a combined X-ray, NMR spectroscopy, and molecular modeling approach. In the solid state, the binding arms of the free receptors 7 delimit a cleft in which two solvent molecules are hydrogen bonded to the pyrrolic groups and to the benzenic scaffold. In a polar solvent (CD3CN), chemical shift and intermolecular NOE data, assisted by molecular modeling calculations, ascertained the binding modes of the interaction between the receptor and the glycoside for these complexes. Although a single binding mode was found to adequately describe the complex of the acyclic receptor 5 with the alpha-mannoside, for the complexes of the cyclic receptors 7 two different binding modes were required to simultaneously fit all the experimental data. In all cases, extensive binding through hydrogen bonding and CH-pi interactions is responsible for the affinities measured in the same solvent. Furthermore, the binding modes closely account for the recognition preferences observed toward the anomeric glycosides and for the peculiar enantiodiscrimination properties exhibited by the chiral receptors.