title: Alpha-galactosyl fluoride in transfer reactions mediated by the green coffee beans alpha-galactosidase in ice.
abstract: We show that the yields in saccharide synthesis by tranglycosylation with alpha-galactosidase from green coffee beans can be greatly enhanced when working in ice. Thus, methyl alpha-D-galactopyranosyl-(1-->3)-alpha-D-galactopyranoside (3a) produced by reaction of alpha-D-galactopyranosyl fluoride 1 with methyl alpha-D-galactopyranoside (2) is obtained with 51% yield in ice while only 29% is synthesized at 37 degrees C. This result, already previously found by others with proteases and by us with a beta-galactosidase appears to be a general property of hydrolases.
authors.affiliation: Unité de Recherches en Biocatalyse (unité CNRS 2230), Faculté des Sciences et des Techniques, 2, rue de la Houssinière, BP 92208, F-44322, Nantes, France.
authors.forename: Petra
authors.initials: P
authors.lastname: Spangenberg
authors.forename: Corinne
authors.initials: C
authors.lastname: André
authors.forename: Virginie
authors.initials: V
authors.lastname: Langlois
authors.forename: Michel
authors.initials: M
authors.lastname: Dion
authors.forename: Claude
authors.initials: C
authors.lastname: Rabiller
mesh_terms: D003069:Coffee / Q000201:enzymology*; D004187:Disaccharides / Q000378:metabolism*; D006867:Hydrolases / Q000378:metabolism; D007700:Kinetics; D009005:Monosaccharides / Q000378:metabolism*; D013696:Temperature; D000519:alpha-Galactosidase / Q000378:metabolism*
chemical_list: D003069:Coffee; D004187:Disaccharides; D009005:Monosaccharides; C457441:galactopyranosyl fluoride; C457442:methyl-galactopyranosyl-(1-3)-galactopyranoside; D006867:Hydrolases; D000519:alpha-Galactosidase