Compounds Combining a Macrocyclic Building Block and Flexible Side-Arms as Carbohydrate Receptors: Syntheses and Structure-Binding Activity Relationship Studies

Abstract

A series of new representatives of compounds combining a macrocyclic building block and flexible side-arms were prepared and their ability to act as carbohydrate receptors evaluated. The target compounds were obtained by multi-step syntheses, which included the preparation of numerous precursors as well as the isolation of a large number of by-products. The structure-binding activity relationship studies comprise, in particular, the variation of the side-arms in order to demonstrate the importance of the presence of a hydrogen bond donor in these units for the effective complexation of carbohydrates. Based on the findings of our previous studies, the variation of the bridge units is limited to benzene- and pyrrole-based moieties, whereby the use of the last-mentioned bridge type was expected to produce more effective systems. This assumption was confirmed by 1H NMR titrations and isothermal titration calorimetry.