Enzymatic Synthesis of 2-Deoxyglycosides Using the ß-Glycosidase of the Archaeon Sulfolobus solfataricus

The synthesis of 2-deoxyglycosides and, for the first time, of 2-deoxygalactosides is reported using a thermo- philic and thermostable b-glycosyl hydrolase from the archeon Sulfolobus solfataricus and glucal or galactal as donors. The yields observed with alkyl acceptors confirmed that the robustness of the biocatalyst is of great help in designing practical syntheses of pure b-anomers of 2- deoxy derivatives of 4-penten-1-ol (obtained in 80% yield at 20 fold molar excess) and 3,4-dimethoxybenzyl alcohol (obtained in 19% yield at 3.3 fold molar excess). The attachment of 2-deoxyglyco units was performed on various pyranosidic acceptors (p-nitrophenyl a-D-gluco- pyranoside, o-nitrophenyl 2-deoxy-N-acetyl-a-D-glucosamine and p-nitrophenyl 2-deoxy-N-acetyl-b-D - glucosamine). At low molecular excesses of the acceptors, satisfactory yields (20/40%) of chromophoric 2-deoxy di- and trisaccharides were obtained. The different regioselectivity of our enzyme with respect to mesophilic counterparts reflects the importance of biodiversity in this field for the construction of a library of different glycosidases with different specificity.