Abstract
The production of analytical amounts of azido sugars is used as a means of verifying catalytic acid/base mutations of retaining glycosidase, but application of this process to preparative synthesis has not been reported. The catalytic acid/base mutant of Thermoanaerobacterium xylanolyticus GH116 β-glucosidase, TxGH116D593A, catalyzed the gram scale production of 1-azido-β-d-glucose (1) from p-nitropheyl-β-d-glucopyranoside (pNPGlc) and azide via a transglucosylation reaction. Overnight reaction of the enzyme with pNPGlc and NaN3 in aqueous MES buffer (pH 5.5) at 55 °C produced 1 (3.27 g), which was isolated as a white foamy solid in 96% yield. This 1 was successfully utilized for the synthesis of fifteen 1,2,3-triazole-β-d-glucosyl derivatives (2-16) containing a variety of functional groups, via click chemistry.