Study On Surfactant-ultrasonic-assisted Extraction Of Total Polyphenols From Eucommia Ulmoides Leaves And Related Activity

Eucommia ulmoides is traditionally used for medicinal purposes.The chemical composition in Eucommia ulmoides leaves is very similar to that in the skin.Polyphenols in plants have various functions such as anti-oxidation,anti-aging,anti-radiation and so on.Polyphenols are often called "seventh nutrients",and have broad application prospects in food,cosmetics and other industries.In this paper,Eucommia ulmoides leaves are used as raw materials to optimize the extraction process of Eucommia ulmoides leaves total polyphenols,and related activity studies are carried out on the Eucommia ulmoides leaves total polyphenols extract,which provides a theoretical basis for the development and application of Eucommia ulmoides leaves in functional foods and cosmetics.The main content and results of the study are as follows:1.Surfactant-ultrasonic-assisted extraction of total polyphenols from Eucommia ulmoides leaves.First,the effects of surfactant types,surfactant dosage,ethanol volume fraction,material-liquid ratio,ultrasonic time,and extraction temperature on the extraction of total polyphenols from Eucommia ulmoides leaves were investigated.Based on the singlefactor experiment,the ethanol volume fraction,material-liquid ratio and temperature were selected for orthogonal experiment.The results showed that the order of three single factors affecting the yield of Eucommia ulmoides leaves total polyphenols was: ethanol volume fraction > extraction temperature > material-liquid ratio.Considering factors such as extraction efficiency,energy consumption and production cost,the optimal process was determined to be SDS dosage 0.1 g / L,ultrasonic extracting time 5 min,ethanol concentration 50%,material-liquid ratio 1?20(g?m L),temperature 45 ?.Under the above extraction conditions,the yield of Eucommia ulmoides leaves total polyphenols reached 6.77%,and without surfactants,the yield was 5.99%.2.Evaluation of antioxidant activity of Eucommia ulmoides leaves total polyphenols extract.Three kinds of total polyphenol extracts(EUE-SDS,EUE-W and EUE-45 Et OH)of Eucommia ulmoides leaves were prepared by the above optimized process,water extraction process and ultrasonic-microwave extraction process,and compared with Vc Determination of scavenging ability and reducing power of hydroxyl radicals,DPPH radicals,ABTS radicals,to investigate the in vitro antioxidant capacity of different extracts.The test results show that the three Eucommia ulmoides leaves total polyphenols extract have hydroxyl radical,DPPH radical,ABTS radical scavenging ability,at the same time,They all have reducing ability.Hydroxyl radical scavenging ability Vc > EUE-SDS > EUE-45 Et OH > EUE-W,DPPH radical scavenging ability Vc > EUE-45 Et OH > EUE-SDS > EUE-W,ABTS radical scavenging ability Vc > EUE-SDS > EUE-45 Et OH > EUE-W,reducing power capacity Vc > EUE-45 Et OH > EUE-SDS > EUE-W.3.Evaluation the antioxidant activity of Eucommia ulmoides leaves total polyphenols extract.With normal saline as the blank group and ascorbic acid(Vc)as the positive control group,healthy KM mice were gavaged and the MDA content,SOD activity and GSH-PX activity in the brain,liver and serum of the mice were measured 42 days later.Compared with the blank control group,the MDA content of liver tissue in Vc group,EUE-W group,EUE-45%Et OH group,and EUE-SDS group was reduced by 27.44%,24.13%,21.63%,and 28.37%,The MDA content of brain tissue was reduced by 17.48%,0.90%,15.33%,11.29%,The MDA content of serum was reduced by 15.43%,5.00%,19.90%,11.36% respectively.SOD activity in liver tissue increased by 6.41%,10.49%,7.74%,8.72%,SOD activity in serum increased by 9.60%,13.60%,7.74%,22.30%,SOD activity in brain tissue increased by 5.38%,1.01%,7.70%,2.70% respectively.GSH-PX activity in liver tissue increased by 40.41%,27.75%,39.27%,26.48%,GSH-PX activity in brain tissue increased by 9.52%,57.02%,30.00%,6.10%,and GSH-PX in serum tissue PX vitality increased by 23.60%,12.60%,43.45,18.43% respectively.4.Preliminary study on the effect of Eucommia ulmoides leaves total polyphenol extract on tyrosinase activity.Preliminary investigations on the tyrosinase activity of three Eucommia ulmoides leaves total polyphenol extracts showed that the three Eucommia ulmoides leaves total polyphenol extracts all had inhibitory effects on tyrosinase.The increase in the inhibitory effect on the activity of tyrosinase is improved,and the inhibitory effect of EUE-SDS on tyrosinase is better than that of EUE-W and EUE-45 Et OH.The highest inhibition rates in the experimental concentration range were 41.90%,34.30%,33.40% respectively.