51. Purification of an isoflavonoid 7-O-beta-apiosyl-glucoside beta-glycosidase and its substrates from Dalbergia nigrescens Kurz.
- Author
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Chuankhayan P, Hua Y, Svasti J, Sakdarat S, Sullivan PA, and Ketudat Cairns JR
- Subjects
- Catalysis, Hydrolysis, Kinetics, Seeds enzymology, Substrate Specificity, Dalbergia enzymology, Disaccharides chemistry, Disaccharides metabolism, Glycoside Hydrolases isolation & purification, Glycoside Hydrolases metabolism, Isoflavones chemistry, Isoflavones metabolism
- Abstract
A beta-glycosidase was purified from the seeds of Dalbergia nigescens Kurz based on its ability to hydrolyse p-nitrophenyl beta-glucoside and beta-fucoside. This enzyme did not hydrolyze various glycosidic substrates efficiently, so it was used to identify its own natural substrates. Two substrates were identified, isolated and their structures determined as: compound 1, dalpatein 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside and compound 2, 6,2',4',5'-tetramethoxy-7-hydroxy-7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (dalnigrein7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside). The beta-glycosidase removes the sugar from these glycosides as a disaccharide, despite its initial identification as a beta-glucosidase and beta-fucosidase.
- Published
- 2005
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