Low-Symmetry Macrocycles and Cages for Carbohydrate Recognition

The recognition of carbohydrate plays a key role in numerous biological processes. Thus, artificial receptors have been synthesized to mimic these biological systems. To date, most of the receptors reported for carbohydrate complexation present highly symmetrical cavities, probably because their syntheses require less synthetic efforts and are easier to achieve and control. However, carbohydrates display complex, asymmetrical structures suggesting that hosts with low symmetry might be more adapted to recognize these guests. Here, we described the strategies that have been used to complex carbohydrates with macrocycles and cages presenting low symmetry and the potential of this approach. Self-assembled cages are first described, then covalent macrocycles and cages are presented and for each example the binding properties of low-symmetry systems are compared to those of their higher-symmetry counterparts.