| Hemerocallis Fulva is liliaceae of perennium,belonging to Hemerocallis,widely distributed in China's north and south provinces,abundant in natural resources.Hemerocallis Fulva flowers,also known as the Chinese “mother flower”,is a flower that “views for flowers”,“uses for medicine” and “eats for vegetables”.In this study,Hemerocallis Fulva flower as raw material,the extraction rate indicators flavonoid optimized ultrasonic assisted extraction process,Hemerocallis Fulva flower was purified flavonoid extract by macroporous resin,by high performance liquid chromatography-diode array detector(HPLC-DAD)qualitative and quantitative analysis of flavonoids in different varieties of Hemerocallis Fulva flowers,providing theoretical support for deep processing of Hemerocallis Fulva flower resources.The main conclusions were as follows:(1)Extracting flavonoids from the Hemerocallis Fulva flower,on the basis of single factor experiment,the choice of flavonoids had a greater influence on the extraction yield of three factors on the response surface optimization design results show that the response surface regression model,no significant loss of quasi phase,the response surface regression model is established for forecast Hemerocallis Fulva flower extract flavonoids,ultimately determine the best extraction conditions of flavonoids in Hemerocallis Fulva flower: ethanol volume fraction is 75%,23 min ultrasonic time,ultrasonic power 198 w,Hemerocallis Fulva flowers under the conditions of flavonoids extraction yield was 91.15%,which was close to the predicted value 91.73%.(2)The static adsorption and desorption properties of six resins were investigated.By comparison,it was found that the adsorption capacity,analytical rate and purification rate of AB-8 macroporous resins were the highest,which was suitable for the crude extract of flavonoids from the Hemerocallis Fulva flower.The dynamic adsorption process was optimized with the leakage point as the index.The latest conditions of the leakage point were flow rate of 5BV/h,pH 4 and the concentration of the upper sample was 1.0mg/mL.Under these conditions,the dynamic adsorption of the resin was the highest.For the dynamic desorption process,ethanol with different volume fraction was used as the eluent for desorption,and 80% of ethanol had the best desorption effect.Through the macroporous resin desorption and adsorption,the purity of flavonoid was increased from 12.35% to 43.28%,and its purity was increased by 3.5 times.(3)A high performance liquid chromatography method for detecting flavonoids in Hemerocallis Fulva flowers was established,the conditions for column temperature 35?,sample quantity 10?L,flow rate of 0.8mL/min,scanning wavelength of 254 nm and 280 nm,Mobile phase A is 0.1% aqueous formic acid,B is acetonitrile,gradient elution procedure: 0~2min,A is 95%~95%;2~10min,A is 95%~80%;10~20min,A is 80%~75%;20~25min,A is 75%~ 75%;30~45min,A is 75%~40%.The flavonoids content of 20 kinds of Hemerocallis Fulva were detected,and catechins,isocatechins,rutin,isoquercetin and chrysin.By measuring the DPPH free radical scavenging rate and ·OH radical scavenging rate,the antioxidant activity in vitro was expressed by vitamin C(Vc)equivalent.Hemerocallis Fulva flowers "red beibei" has the highest in vitro antioxidant activity,and Hemerocallis Fulva flowers "mu yangren" has the lowest in vitro antioxidant activity.The relationship between flavonoid composition and antioxidant activity was established by partial least squares(PLS).The correlation between iso-catechin,rutin and isoquercetin was better than that of antioxidant. |
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