Study On Extraction,Purification And Biological Activities Of Flavonoids From Uraria Crinita Root

Uraria crinita is a kind of herbal medicine abounding in the south of Fujian province. In this thesis, Uraria crinita root was utilized as raw materials to extract flavonoids, and then conducted its separation and purification for study on the biological activity of flavonoids from Uraria crinita root, which will provide theoretical support for the development of flavonoids from Uraria crinita root.?1? The optimal extraction conditions of total flavonoids from Uraria crinita were obtained via the single-factors test as follows:temperature of 60 ?, solid-liquid ratio of 1:25 ?g/mL?, ethanol concentration of 70%?V/V? and time of 4 h. Under the optimal conditions, the yield of total flavonoids from Uraria crinita root was 48.44 mg·g^-1.?2? It was found that the ADS-17 was the most suitable macroporous resin among 4 kinds of these used ?D101?HPD600?ADS-17 and AB-8? through testing the performance of absorption and desorption. The optimal purification conditions were as follows: flavonoids concentration of 0.6 mg·mL^-1, sample flow rate of 3 mL·min^-1, sample solution volume of 4 BV, elution solution volume of 3.5 BV with 70%ethanol, and desorption flow rate of 2 mL·min^-1. Under these conditions, the product UCB-1 obtained with 42.18% of flavonoids and the product UCB-2 with 61.33% of flavonoids was obtained followed by purification using silica gel chromatography.?3? The structure of the product UCB-2 was deducted as rutin through the characterization of UV, FTIR and HPLC.?4? The antioxidant activity experiments for flavonoids from Uraria crinita root were conducted in vitro, suggesting that the general antioxidant capacity of flavonoids after extraction stronger than that before extraction, the total antioxidant capacity and scavenging capacity of hydroxyl radical of flavonoids extracted with n-butyl alcohol stronger than that extracted with ethyl acetate but weaker than Vc, and the scavenging capacity of superoxide anion radical of flavonoids extracted with n-butyl alcohol and ethyl acetate stronger than Vc.?5? The experiments about the inhibitory capacity on ?-amylase and a-glycosidase were performed with flavonoids extracted using n-butyl alcohol and ethyl acetate. The flavonoids extracted with n-butyl alcohol showed certain a-amylase inhibition at pH 6.5?7.5 with good thermal stability, and the maximum inhibitory capacity on a-amylase when being preheated in 37? for 30 min, while the flavonoids extracted with ethyl acetate did not have an obvious inhibition capacity on a-amylase. Besides, the flavonoids extracted with n-butyl alcohol and ethyl acetate have not showed an a-glycosidase inhibition.