Reaction: a 6-O-(β-D-xylopyranosyl)-β-D-glucopyranoside + H2O = 6-O-(β-D-xylopyranosyl)-β-D-glucopyranose + an alcohol
Glossary
primeverose = 6-O-(β-D-xylopyranosyl)-D-glucose
vicianose = 6-O-(α-L-arabinopyranosyl)-D-glucose
Systematic name: 6-O-(β-D-xylopyranosyl)-β-D-glucopyranoside 6-O-(β-D-xylosyl)-β-D-glucohydrolase
Comments: The enzyme is responsible for the formation of the alcoholic aroma in oolong and black tea. In addition to β-primeverosides [i.e. 6-O-(β-D-xylopyranosyl)-β-D-glucopyranosides], it also hydrolyses 6-O-(β-D-apiofuranosyl)-β-D-glucopyranosides and, less rapidly, β-vicianosides and 6-O-(α-L-arabinofuranosyl)-β-D-glucopyranosides, but not β-glucosides. Geranyl-, linaloyl-, benzyl- and p-nitrophenol glycosides are all hydrolysed.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 884593-92-4
References
1. Ijima, Y., Ogawa, K., Watanabe, N., Usui, T., Ohnishi-Kameyama, M., Nagata, T. and Sakata, K. Characterization of β-primeverosidase, being concerned with alcoholic aroma formation in tea leaves to be processed into black tea, and preliminary observations on its substrate specificity. J. Agric. Food Chem. 46 (1998) 1712-1718.
2. Ogawa, K., Ijima, Y., Guo, W., Watanabe, N., Usui, T., Dong, S., Tong, Q. and Sakata, K. Purification of a β-primeverosidase concerned with alcoholic aroma formation in tea leaves (cv. Shuxian) to be processed to oolong tea. J. Agric. Food Chem. 45 (1997) 877-882.