The Enzymatic Hydrolysis Of The Glycoside And Antioxidant Activity

Synthetical antioxidants ,such as BHT and BHA ,were improved to do harm to people抯 health. In order to seek the natural innoxious and effective antioxidants ,research was carried out as a hotspot today. Extracted from natural plants, flavones, which are the most potential natural multifunctional antioxidants, have little toxicity but lots of bioactivities. Most of natural flavones are in existance by flavoneglucosides which have faintish antioxidative and foreclose their applications. In order to increasing antioxidative of flavoneglucosides ,we carried out experiments to change flavoneglucosides to flavones by ~ - glucosidase produced by Aspergullus niger .The main contents and results are as follows: 1. Extracted isoflavone from soybean and Pueraria Lobata by 95% ethanol, the extraction contents daidzin 10.41% and 47.2%; extracted flavoneglucosides from Sophora Japonica and Scutellarica Baicalensis by hot water, the former extraction contents Rutin 89.6%. 2. The results of all extractions antioxidation in oil system showed that more daidzin in soybean and Pueraria Lobata extractions lower antioxidativities they represented. Quercetin was more effective than Rutin in oil oxidation system. 3. Choose Aspergullus Niger as ~ -glucosidase higherproducer. After optimaling its fermentation culture medium , ~ -glucosidase activity increased from 20.IU/ml to 28 lU/mi. 4. P -glucosidase hydrolyzing can made several extractions and flavoneglucoside change to relevant flavone. 5. Using 0.1% each fore-and-aft. enzyme hydrolyzing sample to do oil antioxidation experiment, results showed that antioxidativity of samples increased in different degree after enzyme action. After II enzyme hydrolyzing, the antioxidation effect of Rutin and Scutellarica Baicalensi flavone was notable and equivalent to BHT. 6. Applying method CNDO/2 to optimal and calculate the structures of flavonoids,~ including Rutin, Qcercetin ,dadzin , dadzein, Genistin and Genitstein et.al. Calculation results were used to discuss the antioxidation mechanism of flavones and explain the reason of the experiment facts that the flavoneglucoside antioxidative lower than flavonoids in oil oxidation system.