title: A prototype calix[4]arene-based receptor for carbohydrate recognition containing peptide and phosphate binding groups.
abstract: A novel class of macrobicyclic receptors for carbohydrate recognition based on upper rim, peptide-bridged calix[4]arenes has been designed and synthesized. Receptor 12, in which a charged phosphate group cooperates with peptide hydrogen-bonding donor and acceptor groups in the binding process, is the most efficient and selective in the complexation of simple carbohydrate derivatives. The selectivity observed is toward beta-glucoside 13a, which is better bound (DeltaG degrees = 19.6 kJ mol(-)(1)) compared to the corresponding alpha anomer 13b (DeltaG degrees = 17.0 kJ mol(-)(1)) and to the beta-galactoside 13c (DeltaG degrees = 17.7 kJ mol(-)(1)) in CDCl(3). A substantial drop in the stability constant is observed by esterification of the phosphate group in the host 12 or by alkylation of the OH groups in the 2 and 3 positions in the beta-glucoside and beta-galactoside derivatives. On the basis of a careful analysis of the (1)H NMR data available, a binding mode of the beta-octylglucoside 13a to receptor 12 is proposed.
authors.affiliation: Dipartimento di Chimica Organica e Industriale, Università degli Studi, Parco Area delle Scienze 17/A, I-43100 Parma, Italy.
authors.forename: Margarita
authors.initials: M
authors.lastname: Segura
authors.forename: Barbara
authors.initials: B
authors.lastname: Bricoli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Casnati
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Muñoz
authors.forename: Francesco
authors.initials: F
authors.lastname: Sansone
authors.forename: Rocco
authors.initials: R
authors.lastname: Ungaro
authors.forename: Cristina
authors.initials: C
authors.lastname: Vicent
mesh_terms: D047250:Calixarenes; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D007202:Indicators and Reagents; D010455:Peptides; D010710:Phosphates; D011083:Polycyclic Compounds; D047250:Calixarenes