Enzymatic synthesis of disaccharides using Agrobacterium sp. β-glucosidase

The synthesis of several oligosaccharides, in yields up to 65%, has been achieved by utilizing the transglycosylation activity of Agrobacterium sp. β-glucosidase (EC 3.2.1.21). The regioselectivity of the glycosylation reaction was investigated using p-nitrophenyl β-d-galactopyranoside, β-d-mannopyranosyl fluoride and d-glucal as glycosyl donors and a series of phenyl 1-thio-, benzyl 1-thio-, and benzyl β-d-glycopyranosides as glycosyl acceptors. The isolated products were determined to contain a mixture of β-(1 → 3) and/or β-(1 → 4) glycosidic linkages for all glycosyl acceptors, except for β-d-galacto-configured acceptors where a mixture of β-(1 → 3) and β-(1 → 6) linkages was observed. The wide range of glycosyl donors and acceptors utilized by the enzyme in transglycosylation experiments demonstrates the versatility of this system for the aqueous-phase synthesis of oligosaccharides.