title: Hydrolysis of flavonoid glycosides by propolis β-glycosidase.
abstract: Flavonoids generally occur as O-glycosides with sugars bound in nature, while aglycones and their derivatives are the main flavonoids in propolis. The objective of this work was to study the propolis β-glycosidase activities toward flavonoid β-glycosides and their conjugated forms. β-Glycosidase was extracted from propolis, incubated with ﬂavonoid glycosides, and analysed for aglycone formation by HPLC. The results demonstrated that glucose conjugates were rapidly hydrolysed, but not conjugates with other sugars, i.e. rutin and naringin. The rate and extent of deglycosylation depends on the structure of the ﬂavonoid and the position of the sugar substituitions. Quercetin 3-O-glucoside had the highest percent of hydrolysis, while quercetin 7-O-glucoside was the least hydrolysed. The K(m) values for hydrolysis of apigenin 7-glucoside and luteolin-7-O-glucoside were 13 µM and 20 µM, respectively.
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310029, China.
authors.forename: Cui-Ping
authors.initials: CP
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Fu-Liang
authors.initials: FL
authors.lastname: Hu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry*; D006868:Hydrolysis; D011429:Propolis / Q000737:chemistry*; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D006027:Glycosides; D011429:Propolis; D001617:beta-Glucosidase