Preparation And Chemical Characterrization Of Total Flavonoids Active Site From Dracocephalum Tanguticum

Tanguticum is a herbaceous plants belongs to Dracocephalum of Labiatae,which is Tibetan medicine and is often used to treatment of hepatritis,gastritis,gastric ulcer and bleeding.It is widely distributed in Tibet,Qinghai,Sichuan and Gansu provinces.In this study,with the study object of active site of flavonoids from Tanguticum,the determination of total flavonoids method was chosen by colorimetric method.On the basis of single factor experimental results,Box-Behnken response surface method was used to establish an optimal model of total flavonoids extraction process.The purification process of total flavonoids was optimized by macroporous resin adsorption.On the base of the studies of preparation technology,the UPLC-Q-TOF/MS method was used to identify the chemical composition of the active fraction of total flavonoids.Evaluation of antioxidant activity of total flavonoids by DPPH.The main research rasults were as follows:(1)Comparative the UV direct measurement method with the HCl-Mg color developement method,and the method for the determination of total flavonoids in Tanguticum was determined.(2)The best extraction technology of optimization of ultrasonic-assisted total flavonoids from Tanguticum by response surface method were:ratio of solid to liquid 1:25 g/mL,ethanol concentration 58%,extraction temperature 48℃,extraction time 12 min.Under this optimal conditions,the total flavonoids yield of Tanguticum reached 14.4%,and the verification experiments show that the process was stable and feasible.(3)The optimum macroporous resin HPD826 was selected from seven kinds of macroporous resin,and the best purifying process were: the concentration of the sample solution was 1.7 mg/mL,the sample flow rate was 2mL/min,the ratio of diameter to height of resin bed was 1:9,and the volume of the sample solution was 35 mL,120mL 55% alcohol as eluent and desorption rate at 1mL/min,Under this conditions,the content of total flavonoids active site reached 87%.(4)Eleven phenolic acids and flavonoids were identified by optimized UPLC-Q-TOF/MS method from the total flavonoids of Tanguticum,and the Tricin-7-O-glucoside was identified from Tanguticum for the first time.(5)The purification site and extraction site of total flavonoids from showed good scavenging ability to DPPH free radicals,and the effect of purification site better than that extraction site.This result showed that the active site of flavonoids in Tanguticum had certain antioxidant activity.