title: Exploration of conformational flexibility and hydrogen bonding of xylosides in different solvents, as a model system for enzyme active site interactions.
abstract: The predominantly populated conformation of carbohydrates in solution does not necessarily represent the biologically active species; rather, any conformer accessible without too large an energy penalty may be present in a biological pathway. Thus, the conformational preferences of a naphthyl xyloside, which initiates in vivo synthesis of antiproliferative glycosaminoglycans, have been studied by using NMR spectroscopy in a variety of solvents. Equilibria comprising the conformations (4)C1, (2)SO and (1)C4 were found, with a strong dependence on the hydrogen bonding ability of the solvent. Studies of fluorinated analogues revealed a direct hydrogen bond from the hydroxyl group at C2 to the fluorine atom at C4 by a (1h)JF4,HO2 coupling. Hydrogen bond directionality was further established via comparisons of fluorinated levoglucosan molecules.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Jerk
authors.initials: J
authors.lastname: Rönnols
authors.forename: Sophie
authors.initials: S
authors.lastname: Manner
authors.forename: Anna
authors.initials: A
authors.lastname: Siegbahn
authors.forename: Ulf
authors.initials: U
authors.lastname: Ellervik
authors.forename: Göran
authors.initials: G
authors.lastname: Widmalm
mesh_terms: D020134:Catalytic Domain; D006027:Glycosides / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry
chemical_list: D006027:Glycosides; D012997:Solvents; C010807:xylosides