title: NMR studies on the interaction between (-)-epigallocatechin gallate and cyclodextrins, free and bonded to silica gels.
abstract: The interaction between (-)-epigallocatechin-3-gallate (EGCG) and beta- or gamma-cyclodextrin (CD), in free solution and bonded to silica beads, has been studied by (1)H HR-MAS NMR spectroscopy. The chromatographic retardation of EGCG on columns packed with CD-silica beads was shown to be due to the interaction of EGCG with the CD ligands because no nonspecific interaction with the silica gel could be observed. EGCG forms a tighter complex with beta-CD than with gamma-CD and NMR data obtained from hydroxy protons together with MM2 calculations suggest that for beta-CD intermolecular hydrogen bonding, in addition to hydrophobic interaction, stabilizes the complex.
authors.affiliation: College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Tianwei
authors.initials: T
authors.lastname: Tan
authors.forename: Jan-Christer
authors.initials: JC
authors.lastname: Janson
authors.forename: Lennart
authors.initials: L
authors.lastname: Kenne
authors.forename: Corine
authors.initials: C
authors.lastname: Sandström
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003505:Cyclodextrins; D012822:Silicon Dioxide; D002392:Catechin; C045651:epigallocatechin gallate