α-Galactosyl fluoride in transfer reactions mediated by the green coffee beans α-galactosidase in ice Original Research Article

We show that the yields in saccharide synthesis by tranglycosylation with α-galactosidase from green coffee beans can be greatly enhanced when working in ice. Thus, methyl α-d-galactopyranosyl-(1→3)-α-d-galactopyranoside (3a) produced by reaction of α-d-galactopyranosyl fluoride 1 with methyl α-d-galactopyranoside (2) is obtained with 51% yield in ice while only 29% is synthesized at 37 °C. This result, already previously found by others with proteases and by us with a β-galactosidase appears to be a general property of hydrolases.