Enzyme-catalyzed cleavage of the C-glycosidic linkage to the aromatic ring-A of 3',4',5,7-tetrahydroxyflavone 8-C-glycoside.
It was demonstrated that 8-C-beta-D-glucopyranosyl-3',4',5,7-tetrahydroxy- flav-2-en-3-one (orientin) undergoes enzyme-catalyzed deglucosylation to form the sugar-free aglycone, 3',4',5,7-tetrahydroxyflav- 2-en-3-one (luteolin). The enzyme was partially purified by ammonium sulfate precipitation, followed by fractionation through Sephadex G-100 gel. The enzymic deglycosylation proceeded at pH 5.4 in an incubation system containing enzyme preparation isolated from Carthamus tinctorius and orientin, with no distinct requirement for atmospheric oxygen. It was activated markedly by the addition of H2O2 and inhibited prominently in the presence of iron ions, KCN or o-phenanthroline.
Saito
K
K
Department of Bioscience and Technology, School of Engineering, Hokkaido Tokai University, Sapporo, Japan.
D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000378:metabolism*; D005960:Glucosides / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D010944:Plants / Q000201:enzymology*; D011096:Polygalacturonase / Q000378:metabolism; D001617:beta-Glucosidase / Q000378:metabolism
D005419:Flavonoids; D005960:Glucosides; D006027:Glycosides; D011096:Polygalacturonase; D001617:beta-Glucosidase; C065886:orientin