The Extraction,Puirfication,Antioxidant Activity And Identification Of Flavonoids From Pericarp Of Hickory Nut

In this study, pericarp of hickory nut as raw materials, the use of ultrasonicassisted extraction of total flavonoids, and then purified by macroporous resin andstudies antioxidant activity of total flavonoids extracts, analysis purified flavonoidsextracts by HPLC/Q-TOF-MS method. The results are as follows:(1) Use ultrasonic assisted extraction of flavonoids from pericarp of hickorynut, flavonoids yield and purity as the indexes. The single-factor experiment selectmaterial liquid, ultrasonic extraction time, extraction temperature and ethanolconcentration as4factors, under conditions of ultrasonic power250W. On the basisof single factor experiments, the second common rotation test select three significantinfluence elements on the yield and purity of flavonoids,ultrasonic assisted extractionof flavonoids from the optimum conditions: liquid ratio1:12, temperature72°C,extraction time52min. Under this condition, the yield of flavonoids is2.19%, thepurity can reach16.62%.(2) The optimum conditions for extracting total flavonoids of the pericarp ofhickory nut. With the recovery rate and purity of flavonoids as indexes, optimumprocess condition for separation and purification of flavonoids from pericarp ofhickory nut with macroporous resin was studied. By static and dynamic adsorptionand desorption, D101type macroporous resin is respectively the best for separationand purification of flavonoids from pericarp of hickory nut among four types ofmacroporous adsorption resin chosen. The optimum process condition for flavonoidsof pericarp of hickory nut was the loaded amount of flavonoids vs dry resin:1:8, theextract solution at a concentration under9.9mg/mL. After eluted with5BV of70%ethanol, the yield of flavonoids was above67%and product purity was above70%.(3) The concentration of purified total flavonoid extracts from pericarp ofhickory nut and VC were positively correlated with the scavenging effect of DPPHradicals, hydroxyl radical, superoxide anion and reducing power. The totalflavonoids extracts on the scavenging effect of DPPH radicals, hydroxyl radical andreducing power is lower than the VC. The gap between them increased withincreasing concentrations. At low concentrations, flavonoids extracts are onsuperoxide anion scavenging ability of VC. After, with the increase of theconcentration, VC scavenging greater than flavonoids extracts. IC50of flavonoidsextracts on DPPH radical was0.039mg/mL, and with an IC50of VC for0.035mg/mL.IC50of flavonoids extracts value of the hydroxyl radical0.309mg/mL with an IC50of VC for0.172mg/mL. IC50of flavonoids extracts value of the superoxide anion0.113mg/mL with an IC50of VC for0.110mg/mL.(4) Analyze the main peak of the purified flavonoids extracts of pericarp ofhickory nut by HPLC/Q-TOF-MS method, using the positive ion mode, calculatedby a mass spectrometer to get the accurate molecular weight compounds, withmasslynx softwareelements. Mass spectrometry on the basis of the two fragments ofinformation, and reference data in the literature to determine the seven majorcompounds were5-hydroxy-6,7-dimethoxy flavanone, Physcion, Chrysophanol,5-hydroxy-4’,7-dimethoxy flavanone, Pinostrobin, Pinoeembrin,7-hydroxy-2’,4’-dimethoxy flavanone. Among them, Physcion and Chrysophanol are anthraquinone,the remaining five kinds are flavonoids.