Seperation And Antioxidant Activity Of Total Flavonoids From Sedum Aizoon

Sedum aizoon,also known as cabbage,Sedum notoginseng,is a perennial herb of Sedum family.It tastes bitter when it is eaten.It has a certain inhibitory effect on heart disease and diabetes mellitus,and has the effect of nourishing heart and lowering blood lipid.In this paper,Sedum aizoon in Mianyang area of Sichuan Province was used to study the optimization of the extraction process of total flavonoids from Sedum aizoon,and the purification of total flavonoids from Sedum aizoon by macroporous resin.The total flavonoids of Sedum aizoon were extracted and separated by organic solvent,and the antioxidant activities of its poles were studied by principal component analysis.Finally,the total flavonoids of Sedum aizoon with different poles were preliminarily identified and studied.The main research contents and results are as follows:（1）By single factor experiment,the effects of each single factor on the extraction of total flavonoids from Sedum aizoon Caulis and leaves were compared,and the extraction conditions were optimized by response surface methodology.The antioxidant activities of total flavonoids from Sedum aizoon Caulis and leaves at the same mass concentration were studied with Vc（ascorbic acid）and BHA（tert-butyl hydroxyanisole）as control.The results showed that the same single factor had different effects on the extraction of total flavonoids from the stems and leaves of Sedum aizoon philoxeroides.The optimum extraction conditions of total flavonoids from stems were as follows:ratio of material to liquid 1:64,temperature 88.5℃,extraction time 4 h,ethanol concentration 80%.The optimum extraction conditions were as follows:ratio of material to liquid 1:52,temperature87℃,extraction time 3.31 h,ethanol concentration 81%.Under the optimum extraction conditions,the yield of total flavonoids from stems and leaves was 1.61%,4.13%.（2）By comparing the static adsorption and desorption properties of D-101,AB-8,X-5 and DA-201 macroporous adsorption resins for total flavonoids of Sedum aizoon,the most suitable resin and the best static adsorption-desorption conditions were selected.The purified total flavonoids were preliminarily identified and the antioxidant effects in vitro before and after purification were investigated.It was preliminarily determined that the purified total flavonoids of Sedum aizoon could contain silymarins,hyperosides,kaempferol and quercetin.（3）With Vc and BHA（tert-butyl hydroxyanisole）as positive control,the antioxidant activities of total flavonoids from Sedum aizoon officinalis（Ethyl acetate layer,n-butanol layer,chloroform layer and water layer）were evaluated by principal component analysis using DPPH radical,hydroxyl radical,superoxide anion radical(O^2-·),reducing power,ABTs⁺·cation radical and total antioxidant model in vitro.The results showed that the antioxidant activity of all fractions increased with the increase of flavone concentration,and the ABTs⁺·scavenging ability was the strongest,up to（99.72+0.10）%,which was similar to that of Vc.The OH scavenging rate,O^2-·scavenging rate,total antioxidant FRAP value and other five antioxidant activity indexes of ethyl acetate layer were significantly higher than those of other extraction layers,and DPPH free radical was the strongest scavenging activity of chloroform extraction layer.Principal component analysis showed that the antioxidant activity of ethyl acetate layer was the best.The color reaction and infrared spectrum analysis indicated that ethyl acetate layer and n-butanol layer might be flavonols.Total flavonoids from Sedum aizoon officinalis have strong antioxidant activity and can be used as good raw materials for healthy food development and utilization.