Study On Extraction,purification And Activity Of Flavonoids From Dracocephalum Rupestre Hance Herbal Tea

Dracocephalum rupestre Hance,also known as "Maojian" or "Yanqinglan",is a perennial herbaceous plant of the genus Dracocephalum in the family Lamiaceae,mainly produced in the alpine grasslands of Qinghai,Hebei,Shanxi,Inner Mongolia and other places in China.D.rupestre has high medicinal and health value due to the lack of basic research on D.rupestre,resulting in insufficient development and utilization.This experiment aims to optimize the extraction and purification process of flavonoids in D.rupestre,and study some of their physiological activities,to provide certain theoretical support for the deep processing of Hairy Grass.The main experimental results are as follows:(1)Optimization experiment of extraction process of D.rupestre herbal tea flavonoids.The process parameters of ultrasonic-assisted extraction were determined through experimental exploration,and then the response surface method was used to explore the best process conditions under the interaction of each parameter optimal extraction process based on univariate and response surface results for extracting D.rupestre herbal tea flavonoids by ultrasound-assisted extraction method was 42 m L/g material-liquid ratio,extraction temperature of63 °C,and ethanol concentration of 41 %.The actual extraction rate of tea flavonoids of D.rupestre herbal tea was 9.24 %,and the factors affecting the extraction rate from large to small are ethanol concentration,extraction temperature,and solid-liquid ratio.(2)D.rupestre herbal tea purification process optimization experiment.Using AB-8 macroporous resin as the column,the crude extract of D.rupestre herbal tea flavonoids was purified,and exploring the purification process of flavonoids was through related experiments,dynamic adsorption,and desorption experiment.The specific purification process is: take 190 m L of the sample with a concentration of 1.01 mg/m L and p H 4,load the sample at a flow rate of 1 BV/h,take 65 m L of distilled water to wash at the same flow rate after loading,and take 55 m L of ethanol with a concentration of 70 % to elute at a flow rate of 2 BV/h after washing.After purification by the above process,the purity of D.rupestre herbal tea flavonoids increased from 30.95 % to 82.63 %.(3)Exploration experiment on the physiological activity of D.rupestre herbal tea flavonoids.The exploration of physiological activity is divided into two parts: antioxidant test and in vitro digestion experiment.In the antioxidant activity experiment,the antioxidant capacity of D.rupestre herbal tea flavonoids the results of DPPH radical scavenging,ABTS radical scavenging,and total antioxidant capacity were evaluated,the results show that it has good antioxidant capacity and is positively correlated with the concentration,and the DPPH free radical scavenging rate is the highest at 89.70 %,ABTS free radical scavenging rate was 97.84 %,The total antioxidant capacity was 2.527,and the DPPH radical scavenging rate,about93.53 % and 84.23 % of the control group compared,and the ABTS radical scavenging rate was closest to the control group and about 98 % of the antioxidant capacity of the control group.In vitro digestion experiments,the effects of D.rupestre herbal tea flavonoids on human digestion of starch,protein,and oil were explored by constructing an INFOGEST 2.0 static in vitro digestion model.The experimental results show that D.rupestre herbal tea flavonoids have a certain inhibitory effect on the in vitro digestibility of the three substances,and the inhibitory effect is affected by the concentration,the concentration of 1mg/m L flavonoid purification solution will lead to a decrease of 23.94 % in vitro digestibility of starch compared with the control group,and the in vitro digestibility of starch in this experimental group is only 40.67 % of the control group,this will result in a 29.75 % decrease compared to the control group,which has an in vitro digestibility of 45.44 % of the protein of the control group,about 45.44 % of the control group,and The crude extract of flavonoids at a concentration of 1 mg/m L reduced FFA by 8.66 % compared with the control group,and the release rate of free fatty acids in the experimental group was 65.15 % that of the control group.