Study On Extraction,Purification And Characteristics Of Flavonoids From Artemisia Capillaris

In the traditional Chinese medicine clinical practice,Artemisia capillaris is mainly used to treat jaundice liver and gallbladder diseases;modern pharmacological research shows that Artemisia capillaris also has analgesic and anti-inflammatory,anti-pathogenic microorganisms,anti-tumor and the regulation of blood sugar and blood lipid.The extraction,purification of the flavonoids in Artemisia capillaris which was used as raw material and the study the structure identification,antioxidant activity and stability of the purified materials are intended to provide a reference for the comprehensive utilization and development of Artemisia capillaris.On the basis of investigating the effect of extraction time,extraction temperature,ethanol concentration and liquid-to-material ratio on the yield of the flavonoids from Artemisia capillaris,the Box-Behnken response surface method was used to optimize the extraction process,and the prediction model of two polynomial regression equations was simulated.As a result,the optimal extraction process:extraction temperature of 61?,ethanol concentration of 48%,liquid-to-material ratio of 30:1(mL:g).Under these conditions,the total flavonoids content was 24.89 mg/g.The macroporous adsorption resin was used to separate and purify the total flavonoids of Artemisia capillaris.The seven types of resin(D-101,D-101-I,X-5,AB-8,NKA-9,DA-201,and S-8)were investigated by the adsorption rate,desorption rate and recovery rate of the total flavonoids and the screening result showed that the efficiency of NKA-9 resin is more efficient.The main factors of static adsorption and desorption of NKA-9 resin were investigated.The optimum conditions were as follows:adsorption equilibrium time of 5 h,sample concentration of 0.8 mg/mL,pH of 5.0 and static desorption equilibrium time of 5 h,ethanol concentration of 80%;The reasonable sample loading was 120 mL when the column was packed with 6 g macroporous resin and elution rate at 1 mL/min during dynamic elution,the appropriate amount of eluent was 60 mL;Under the optimal conditions,total flavonoids purified by macroporous resin was increased from 16.1%to 62.1%,and the purification effect was obvious.The composition of purification was analyzed by color reaction,infrared spectroscopy,and liquid chromatography mass spectrometry.As the result of the color reaction,it can be concluded that the extract of Artemisia capillaris must contain flavonol,and may contain one or more of flavonoids,chalcone,dihydroflavone and dihydroflavonol.FT-IR spectra also show that there are many characteristic functional groups such as C=C group,hydroxyl group,phenolic hydroxyl group and so on,which indicated that the extract had the typical structure of flavonoids and the existence of rutin monomers.LC-MS was used to analyze the constituents of flavonoids in the extract.lt was inferred that the extract contained rutin,hyperin,isoquercetin,isorhamnetin-3-O-glucoside and diosmin.The reducing power and the free radical scavenging activity of flavones from Artemisia capillaris were evaluated by determining the discoloration of the DPPH radicals and hydroxyl radicals and superoxide anion radicals.Ascorbic acid was used as positive control.According to comprehensive evaluation,the order of antioxidant activity was ranked as follows:VC>macroporous resin purification>crude extract.The purified substance with a mass concentration of 0.5 mg/mL has the same reducing power as 0.3 mg/mL VC.The results of the stability test of total flavonoids from showed that the total flavonoids were stable within the range of pH 4-6,and were easily damaged in alkaline environment.Mg2+and Al3+have an effect on the stability of total flavonoids,and Ca2+and Fe3+have great influence on the stability.When storing and using the total flavonoid of Artemisia capillaris,it should be avoided in contact with the oxidant.The flavonoids have poor heat resistance and should be used below 60? and stored at 4?.