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[摘要]：Binding motifs observed in the crystal structures of protein carbohydrate complexes, in particular the participation of the isopropyl/isobutyl side chain of valine/leucine in the formation of van der Waals contacts, have inspired the design of new artificial carbohydrate receptors. The new compounds, containing a trisubstituted triethylbenzene core, were expected to recognize sugar molecules through a combination of NH center dot center dot center dot O and OH center dot center dot center dot N hydrogen bonds, CH center dot center dot center dot pi interactions, and numerous van der Waals contacts. H-1 NMR spectroscopic titrations in competitive and noncompetitive media, as well as binding studies in two-phase systems, such as dissolution of solid carbohydrates in apolar media and phase transfer of sugars from aqueous into organic solvents, revealed effective recognition of neutral carbohydrates and beta- vs alpha-anomer binding preferences in the recognition of glycosides as well as significantly increased binding affinity of the receptors toward beta-galactoside in comparison with the previously described receptors. |
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