Study On Preparation And Antioxidant Activity Of Dihydromyricetin In Ampelopsis Grossedentata

This study was prepared dihydromyricetin of high purity.Dihydromyricetin was separated and purified by polyamide column chromatography,and its content was determined by HPLC.Results: The content of dihydromyricetin was up to 98.8% after the twice water crystallization and polyamide chromatography separation.It was measured the content of dihydromyricetin,myricetin and dihydrokaempferol of Ampelopsis grossedentata in different regions.Sephadex LH-20 column chromatography was used to separate three kinds of flavonoid compounds in Ampelopsis grossedentata,and HPLC was used to determine the content of compound.Results: The elution volume of flavonoids was hesperetin(150 mL),dihydrokaempferol(160 mL),taxifolin(100 mL),naringenin(150 mL),DMY(180 mL),eriodictyol(110 mL),kaempferol(180 mL),quercetin(210 mL),myricetin(250 mL)further isolate three compounds including dihydromyricetin,myricetin and dihydrokaempferol and the content was different in different regions.To investigate the scavenging effect of three compounds on DPPH free radical and to study the antioxidant effect of dihydromyricetin on four plant oils.We evaluated its scavenging activity of DPPH on dihydromyricetin,myricetin and dihydrokaempferol by using UV-visible spectrophotometry,and the antioxidant activity of dihydromyricetin on camellia oil,linseed oil,perilla seed oil and oleic acid by oven storagen method.Results: Dihydromyricetin and myricetin have strong scavenging effect on DPPH and the dihydrokaempferol was not,In plant oil oxidation,when the antioxidant dosage was 0.05%,the order of antioxidant activity was TBHQ>dihydromyricetin >BHA>BHT>TP in camellia oil and oleic acid and TBHQ>BHA>BHT>dihydromyricetin>TP in perilla seed oil and Linseed oil;Morever,dihydromyricetin could also help to enhance the role of other antioxidants.Conclusion: Ethanol concentration of 40% could be better elution and separation of dihydromyricetin after the polyamide adsorption.Nine compounds were retained volume between 900-2000 mL by gel column chromatography.The scavenging capacity on DPPH radical was myricetin > dihydromyricetin > dihydrokae mpferol.Antioxidant activity of dihydromyricetin in different plant oils was camellia oil>oleic acid>Linseed oil>perilla seed oil.The results indicated that dihydromyricetin was especially suitable for used as antioxidant of camellia oil.