| Rhodiola sachlinesis A.Bor is one of the most popular traditional Chinese medicines and the extract of the root of this plant has been proved to have many pharmacological effects. So far information on the extraction of flavonoids from Rhodiola sachlinesis is scarce, but some methods were used to extract flavonoids from other Chinese traditional medicines. Such as reflux, microwave extraction, supercritical CO2 extraction and so on. The methods mentioned have disadvantages such as complex procedure, long extraction time and the limitation of extracted components. Consequently,we chose Ultrahigh pressure extraction(UPE) as extraction method for the extraction of flavoniods from Rhodiola sachlinesis. This technique can improve the efficiency and reduce the power consumption.The flavonoids of Rhodiola sachlinesis needs to be purified and bioactivity text for its application. So this paper did some research on the purification and bioactivity texts of flavonoids and provided theoretical bases for its further application.The main content of this paper are as follows:1) UPE was used to extract flavonoids from Rhodiola sachlinesis for the first time. The optimum UPE condition was got by the Uniform design, the optimum regression equation and the optimum UPE conditions were shown below: Y=23.1090484+0.0445254X1+0.7462729X2+403.5558837X3-0.0000239X1X1+0.0002301X1X2-1.3896711X1X3-0.0.101624X2X2-1.4765610X2X3. R2=0.9998,F=534.8979>F0.05(8,1)=239,significant at P﹤0.05The optimum UPE condition was as follows: pressure (MPa)was 500MPa; ethanol concentrationwas 40%; solid/liquid ratiowas 1:70(gcm-3). The optimum extraction yield of flavonoids was 5.233%.Ultrasonic extraction, heat reflux and dipping extraction were chosen as the comparied methods. For the extraction time, UPE was 57min shoter than Ultrasonic extraction, 117min shorter than heat reflux and 77min shorter than dipping extraction. So UPE was the best method to improve the extraction yield of flavonoids and production efficiency.2) Three different methods were chosen as the text methods: ethanol purification, flocculant purification and macroporous adsorption resin purification. For the first method, the purity rate of flavonoids was 15.12%, and rate of getting power was 20.02%. For the second method, chitosan was used as flocculant, pH was 3, the amount of chitosan was 0.02mL/mL(sample), the purity rate of flavonoids was 18.21%, and rate of getting power was 19.06%. For macroporous adsorption resin purification, D101macroporous adsorption resin was used in this study, the amount of the sample used was 1/2 of the BV, pH was 5-6, the concentration of the sample was 3.66-2.44 mg/mL, the eluant was 70% ethanol-water solution, the amount of the eluant was five times of BV, the purity rate of flavonoids was 21.72%, and rate of getting power was 13.15%.This method can delete most of the protein and polysaccharide, the purity rate of flavonoids was the best, and the macroporous adsorption resin can be recovered. So macroporous adsorption resin purification was suitable for purifying the flavonoids from the Rhodiola sachlinesis extract.3) The antioxidant activity was tested in this paper. DPPH method was employed to test the antioxidant activity of the Rhodiola sachlinesis extract. We got that the antioxidant activity of Rhodiola sachlinesis extract with concentration above 0.15mg/mL was higher than TBHQ. At the same time the extracts of different extraction methods were also tested. The antioxidant activity ranking was: the extract of UPE>the extract of ultrasound extractiuon>the extract of dipping method>the extract of reflux.So we could get the conclusion that the UPE can not only improve the extraction efficiency, but also the bioactivity of the extract.
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