Study On The Extraction Processes Of Flavonoids And Volatile Oil From Artemisia Sacrorum Ledeb.

Artemisia sacrorum Ledeb.has long been used as one kind of oriental folk medicine widely distributed in nature and could prevent and treat hepatic injury.It has potential for application as functional food,health keeping medicals and so on.In recent years,there are more and more researches on the pharmacological activities and components of Artemisia sacrorum Ledeb.,with few research about extraction technology reported.Flavonoids and volatile oil from Artemisia sacrorum Ledeb.were comprehensively and systematically evaluated based on their active composition properties.This study optimized the parameters of processes of the flavonoids obtained by ultrasonic-assisted extraction and microwave-assisted extraction,respectively.Meanwhile,the differences were discussed compared with traditional methods.As an evaluation method,the antioxidant activities in vitro were used to determine its bioactivities of the flavonoid-enriched extracts.In addition,orthogonal test were used to optimize the process of volatile oil of Artemisia sacrorum Ledeb.extracted by ultrasound,and its composition together with contents were investigated in the samples by obtained different methods.These results could provide a comprehensive and systematic reference for further development and utilization.The main results are as follows:(1)The effect of four variables on the total flavonoids was investigated,including ethanol concentration,the ratio of material to solvent,ultrasonic power and sonication time.Based on the results of our experiments,orthogonal test design L9(34)was used to optimise the extraction yields of total flavonoids from Artemisia sacrorum Ledeb.The results indicated that the optimum ultrasonic extraction conditions were as follows:ethanol concentration 60%,the ratio of material to solvent 1:20(W/V),ultrasonic power 350 W and sonication time 60 min.Under the above-mentioned conditions,the yields could arrive 69.55 mg.g-1.(2)In the present work,the influence of four parameters(extraction time,the ratio of solvent to material,ethanol concentration and microwave power)on microwave-assisted extraction processes for total flavonoids from Artemisia sacrorum Ledeb.was investigated.Based on single-factor test,Box-Benhnken Design(BBD)was used to optimise the extraction yields of total flavonoids from Artemisia sacrorum Ledeb.,combined with Response Surface Methodology(RSM).The optimum extraction conditions were as follows:extraction time 2 min,ratio of solvent to material 25(V/W),ethanol concentration 40%(V/V)and microwave power 280 W.Under the above-mentioned conditions,the yields arrived to 95.33 mg.g-1,close to the predicted value.(3)Comparing with the traditional methods,ultrasonic-assisted extraction applied to thermal sensitive components due to process in lower temperature.Thus,microwave-assisted extraction has a higher yield than the others.(4)Reducing power and radical scavenging capacities of the flavonoid-enriched extracts were studied using vitamin C(VC)as the positive control.The results indicated that flavonoid-enriched extracts had higher reducing power compared with VC and had effective scavenging capacities against 1,1-diphenyl-2-bitter hydrazine radical(DPPH·),hydroxyl radical(·OH)and superoxide anion radical(O2·-).Meanwhile,the bioactivities appeared to be dose-dependent of flavonoids in certain concentration.So,the flavonoids from Artemisia sacrorum Ledeb.showed significant antioxidant capacities and could be developed as new sources of natural antioxidants.(5)We discussed the effect of the ratio of material to solvent,milling degree,extraction time and ultrasonic power on volatile oil.Based on the results of former investigations,we proposed for orthogonal design L9(34)for determining the extraction yields of volatile oil from Artemisia sacrorum Ledeb.The optimum extraction conditions were as follows:the ratio of material to solvent 1:10,ultrasonic power 400 W,sonication time 40 min and milling degree 80 mesh.Under the above conditions,the yields were 1.5440%.(6)Volatile oil from Artemisia sacrorum Ledeb.was obtained by different extraction techniques,including ultrasonic-assisted extraction(UAE),steam distillation(SD)and supercritical carbon dioxide extraction(SFE-CO2).The volatile compounds were separated and detected by gas chromatography-mass spectrometry(GC-MS).38,42 and 26 compounds were identified in the samples,accounting for 88.98%,93.81%and 83.22%of the total ingredients,respectively.It is further demonstrated that different extraction methods give rise to volatile fractions which differ qualitatively and quantitatively in their compositions.Camphor,3,3,6-trimethyl-1,4-heptadiene-6-ol,cineole,bomeol,and 7R,8R-8-hydroxy-4-isopropylidene-7-methylbicyclo[5.3.1]undec-1-ene were distributed in all samples.Any industrial production in practice should choose corresponding appropriate extraction and separation technology so as to gain better economic benefits.