College of Animal Sciences, Zhejiang University, Hangzhou 310029, China.
Nat Prod Res. 2012;26(3):270-3. doi: 10.1080/14786419.2010.541877. Epub 2011 Aug 19.
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.
类黄酮通常以与天然结合的糖结合的 O-糖苷形式存在，而配糖体及其衍生物是蜂胶中的主要类黄酮。本工作旨在研究蜂胶β-糖苷酶对类黄酮β-糖苷及其共轭形式的活性。从蜂胶中提取β-糖苷酶，与类黄酮糖苷孵育，并通过 HPLC 分析糖苷配基的形成。结果表明，葡萄糖缀合物迅速水解，但与其他糖，即芦丁和柚皮苷的缀合物则不被水解。去糖基化的速率和程度取决于类黄酮的结构和糖取代基的位置。槲皮素 3-O-葡萄糖苷的水解率最高，而槲皮素 7-O-葡萄糖苷的水解率最低。芹菜素 7-葡萄糖苷和木樨草素-7-O-葡萄糖苷水解的 K(m)值分别为 13µM 和 20µM。
