1999 Volume 46 Issue 4 Pages 431-437
β-D-Xylosidase from Aspergillus pulverulentus regioselectively induced a β-D-xylosyl transfer reac-tion from 4-0-β-D-xylopyranosyl-D-xylopyranose (xylobiose) to the primary hydroxyl group of D-glucose. The 6-0-β-D-xylopyranosyl-β-D-glucopyranose (primeverose, 1) produced was isolated by chromatography on a column of charcoal-Celite in a 29% overall yield based on the donor. In the same way, when p-nitrophenyl β-D-glucopyranoside was used as an acceptor instead of D-glucose, the enzyme predominated p-nitrophenyl 6-0-β-D-xylopyranosyl-β-D-glucopyranoside (pNP β-primeveroside, 2) to its isomers, pNP 4-0-β-D-xylopyranosyl-β-D-glucopyranoside and pNP 3-O-β-D-xylopyranosyl-β-D-glucopyranoside. Three transfer products were easily separated from one another by Toyopearl HW-40S column chromatography and the desired compound, 2, was obtained in a 13% yield based on the acceptor added. These reactions were efficient enough. to allow one-pot preparations of 1 and 2.