The hydrolysis of glycosyl fluorides by glycosidases

Abstract

[alpha] -D- and [beta]-D-Glucopyranosyl, [alpha]-D-galactopyranosyl, [alpha]-D-mannopyranosyl and [alpha] -D-xylopyranosyl fluorides were hydrolysed specifically by the respective glycosidases from several sources. Use of specific inhibitors with a mixture of glycosidases from Helix pomatia intestinal juice showed that each glycosyl fluoride was hydrolysed only by the respective glycosidase. [alpha]-D-Glucopyranosidase and [alpha]-D-xylopyranosidase activities were shown to be due to different enzymes. Partially purified enzyme preparations containing only one of the glycosidase activities hydrolyzed only the corresponding glycosyl fluoride. The configuration at C-l of [alpha]-D-mannopyranosyl fluoride was confirmed since it was hydrolysed by an [alpha]-D-mannosidase preparation that contained no detectable [beta]-D-mannosidase activity. An attempt to prepare o-nitrophenyl [beta]-D-mannopyranoside led only to o-nitrophenyl [alpha] -D-mannopyranoside.