Study On Extraction, Purification, Identification, Antioxidation And Antibacteria Of The Flavonoids From Caulis Polygoni Multiflori

Caulis Polygoni Multiflori, our country's traditional Chinese medicine, is the aboveground part of the Radix Polygoni Multiflori Thunb. The raw material of this paper is commercially available Caulis Polygoni Multiflori. The ultrasonical-assisited extraction of Caulis Polygoni Multiflori flavoniod was built with response surface methodology (RSM).Then the extracts by ethyl acetate were separated by silica gel column chromatograph. The in vitro antioxidation activity of different polarity flavonoids from extract of Caulis Polygoni Multiflori were studied by using colorimetry method. Moreover, bacteriostatic action was researched. All this done is aimed for providing theoretical basis for developing and utilizing Caulis Polygoni Multiflori resource.The research results were as follows:1. Ethanol was fitter than other solvents for tatal flavonoids of Caulis Polygoni Multiflori.We discussed the influence of three key factors including ultrasonic power, ultrasonic time and the ethanol concentration on ultrasonical-assisted extraction of Caulis Polygoni Multiflori flavoniods. On the basis of the results above, a quadratic polynomial model evaluating the functions of the three independent variables on the extraction rate of total flavonoids from Caulis Polygoni Multiflori had been maked. The model was well and it can predict the yield of the Caulis Polygoni Multiflori flavonoids. The best conditions of the three factors were obtained which were ultrasonic power of 180 w, ultrasonic time of 48min and the ethanol concentration of 52%. With the best conditions, the extraction rate of total flavonoids from the Caulis Polygoni Multiflori was 3.19%.2. The extracts of the Caulis Polygoni Multiflori flavonoids were rudely separated by different organic solvent. Then the extracts by ethyl acetate dissolved were again separated by Silica gel column chromatography. Four flavonoids components were obtained, which were examined by HPLC and color reaction analysis. One component was likely to be monomeric flanonoids, and it is maybe flavonoids or flavonols.3.The antioxidant activities of different polarity flavonoids from extract of Caulis Polygoni Multiflori were investigated.The results were as follows:in the system of DPPH-, the sequence of scavenging efficiency was Vc>n-butanol extract>ethyl acetate>rough extract≈ethanol extract> water extract; the sequence of deoxidize ability was Vc>ethyl acetate extract>n-butanol extract> ethanol extract>rough extract>water extract; the sequence of scavenging hydroxyl free radical was Vc>ethyl acetate extract>n-butanol extract>ethanol extract>water extract>rough extract; the sequence of scavenging superoxide anion free radical was Vc>ethyl acetate>water extract> ethanol extract≈n-butanol extract,and the greater the concentration of crude extracts, the better the clear results. Caulis Polygoni Multiflori flavonoids could inhibit the lipid peroxidation, but the effect was weaker in comparision with BHT and a-tocopherol.4.Through the experiment of bacteriostasic activity of total flavones in Caulis Polygoni Multiflori, the results showed that MIC values were Staphylococcus aureus 6.25%,Salmonella enteritidis 12.5%,Salmonella typhimurium12.5%,Listeria spp 3.125%; The results are not obvious for Bacillus subtilis, Bacillus cereus and Escherichia coli. There are some influence from PH and ultraviolet radiation for antimicrobial effects.