Dipartimento di Chimica, Università di Firenze, Polo Scientifico e Tecnologico, 50019 Sesto Fiorentino, Firenze, Italy.
Chemistry. 2013 Aug 26;19(35):11742-52. doi: 10.1002/chem.201204298. Epub 2013 Jul 9.
Synthetic ditopic receptors, designed for the molecular recognition of dimannosides, have been prepared by bridging two monotopic units effectively recognizing mannosides with linkers of the appropriate size and flexibility, endowed with hydrogen-bonding groups. Affinities toward the α and β glycosides of the biologically relevant Manα(1-2)Man disaccharide were measured by NMR spectroscopy and isothermal titration calorimetry (ITC) in polar organic media (30-40 % DMF in chloroform). Significant selectivities and affinities in the micromolar range were observed in most cases, with two newly designed receptors being the most effective receptors of the set, together with a distinct preference of the dimannosides for the (S) enantiomer of the receptor in all cases. A 3D view of the recognition mode was elucidated by a combined NMR spectroscopic/molecular modeling approach, showing the dimannoside included in the cleft of the receptor. Compared to the monotopic precursors, the ditopic receptors showed markedly improved recognition properties, proving the efficacy of the modular receptor design for the recognition of disaccharides.
合成的双位受体，设计用于二甘露糖苷的分子识别，通过用具有适当大小和灵活性的连接体桥接两个有效识别甘露糖苷的单一位点单元来制备，该连接体具有氢键供体基团。通过 NMR 光谱和等温滴定量热法（ITC）在极性有机溶剂（30-40％DMF 在氯仿中）中测量对生物相关的 Manα(1-2)Man 二糖的α和β糖苷的亲和力。在大多数情况下，观察到在微摩尔范围内具有显著的选择性和亲和力，其中两个新设计的受体是该组中最有效的受体，并且在所有情况下，二甘露糖苷都明显偏爱受体的（S）对映体。通过结合 NMR 光谱学/分子建模方法阐明了识别模式的 3D 视图，显示了二甘露糖苷被包含在受体的裂缝中。与单一位点前体相比，双位受体显示出明显改善的识别性能，证明了模块化受体设计用于识别二糖的有效性。
