Mimicking the Binding Motifs Found in the Crystal Structures of Protein–Carbohydrate Complexes: An Aromatic Analogue of Serine or Threonine Side Chain Hydroxyl/Main Chain Amide

An aromatic analogue of the side chain hydroxyl/main chain amide of Ser or Thr was used for the construction of artificial receptors for N ‐acetylneuraminic acid (Neu5Ac), the most common occurring sialic acid. The acyclic receptors, incorporating only neutral recognition sites, are able to bind Neu5Ac with an overall binding constant β 2 of 10 5 M –2 in a competitive solvent, such as water‐containing [D 6 ]DMSO. Both receptors show remarkable selectivity for Neu5Ac over D ‐glucuronic acid (GlcA).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)