Purification of an isoflavonoid 7-O-β-apiosyl-glucoside β-glycosidase and its substrates from Dalbergia nigrescens Kurz

• Published in: Phytochemistry (Oxford) Vol. 66; no. 16; pp. 1880 - 1889
• Main Authors: Chuankhayan, Phimonphan, Hua, Yanling, Svasti, Jisnuson, Sakdarat, Santi, Sullivan, Patrick A., Ketudat Cairns, James R.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.08.2005; Elsevier
• Subjects: Apiosyl glucoside; beta-fucosidase; beta-fucoside; beta-glucosidase; beta-jucosidase; Biochemistry & Molecular Biology; Biological and medical sciences; Catalysis; Dalbergia; Dalbergia - enzymology; Dalbergia nigrescens; Dalbergia nigrescens Kurz; dalpatein; Disaccharides - chemistry; Disaccharides - metabolism; enzyme kinetics; enzyme substrates; Enzymes; Fundamental and applied biological sciences. Psychology; glucosides; Glycoside Hydrolases - isolation & purification; Glycoside Hydrolases - metabolism; Hydrolysis; Isoflavones - chemistry; Isoflavones - metabolism; Isoflavonoid glycoside; isoflavonoids; Kinetics; Leguminosae; Life Sciences & Biomedicine; Metabolism; p-nitrophenyl beta-glucoside; plant biochemistry; Plant physiology and development; plant proteins; Plant Sciences; Science & Technology; seeds; Seeds - enzymology; Substrate Specificity; β-Glucosidase; β-Glycosidase substrate; β-Glucosidase; β-Glycosidase substrate; Leguminosae; Dalbergia nigrescens Kurz; Isoflavonoid glycoside; Apiosyl glucoside; beta-glycosidase substrate; beta-glucosidase; leguminosae; FUCOSIDASE; apiosyl glucoside; ENZYME; GLUCOSIDASE; CLONING; SEQUENCE; PANICULATA; isoflavonoid glycoside; EXPRESSION; Seeds; Purification; Molecular structure; Enzyme; Disaccharide; β-Glucosidase: β-Glycosidase substrate; Hydrolysis; Enzymatic activity; Dicotyledones; Glycosidases; Angiospermae; Hydrolases; Spermatophyta; Glycoside
• DOI: 10.1016/j.phytochem.2005.06.024
• ISSN: 0031-9422

A β-glycosidase which hydrolyzes isoflavonoid glycosides, removing β-apiosyl glucose, and two substrates were purified from Dalbergia nigrescens seeds, and the glycoside substrate structures were identified. A β-glycosidase was purified from the seeds of Dalbergia nigescens Kurz based on its ability to hydrolyse p-nitrophenyl β-glucoside and β-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-β- d-apiofuranosyl-(1 → 6)-β- d-glucopyranoside and compound 2, 6,2′,4′,5′-tetramethoxy-7-hydroxy-7-O-β- d-apiofuranosyl-(1 → 6)-β- d-glucopyranoside (dalnigrein7-O-β- d-apiofuranosyl-(1 → 6)-β- d-glucopyranoside). The β-glycosidase removes the sugar from these glycosides as a disaccharide, despite its initial identification as a β-glucosidase and β-fucosidase.