Extraction And Separation Of Effective Components And Study On Antioxidant Activity Of Acanthopanax Trifoliatus

Acanthopanax trifoliatus (L.) Merr. (AT) is a shrub that belongs to the family Araliaceae. This plant is popularly consumed as vegetables and medicinal materials with treatment of eczema, prickly heat and other diseases. There are many reports for the research of AT about effective composition and biological activity, but the systemic research remains to be strengthened. Large area of AT had been planted in Enping, Jiangmen city for many years. In order to make the systematical development and utilization of AT, the thesis had in-depth and systematical research on the effective component separation and antioxidant activity of AT from the following several aspects.First of all, the research had analyzed the antioxidant active ingredient by Ultra Performance Liquid Chromatography tandem Mass Spectrometer (LC-MS), and compared the polyphenol content of 5 varieties of AT stem and leaf alcohol extract, and also analyzed the differences of AT from different parts, extraction layer, and two planting base from February to November. Results showed that:the AT alcohol extract is rich in rutin, chlorogenic acid, isochlorogenic acid A and isochlorogenic acid C; Green-stem showed the highest total polyphenol content among the 5 varieties, AT leaf contained the highest total polyphenol content among diferent parts; Ethyl acetate and n-butanol layers of AT extracts had higher total polyphenol content than petroleum ether layer; The trend of total polyphenol on two planting base from February to November showed basically the same, and AT from April, May and June showed higher total polyphenol than other months.Secondly, this study systematically analyzed antioxidant activity of AT from different varieties, different parts, different planting base and different month. Results showed that Green Stem had the highest activity among different varieties; AT leaves had the highest activity among different parts:the ethyl acetate layer had the highest activity of different extraction layers; the changing trend of AT on two planting base from February to November showed basically the same, and AT from April, May and June showed higher activity than other months.Once again, conditions for extraction process of polyphenols from AT were optimized by means of response surface analysis with the Box-Behnken design method based on the results of the single factor experiments. The optimal conditions of extraction were as follows: 55% ethanol concentration, extraction temperature 75 ℃, extraction time 113 min and ratio of liquid to solid 25 mL·g-1. The actual measured results of polyphenol yield rate was 62.71±1.48 mg/g, which is almost equal to the predictable value. The antioxidant activity was evaluated through DPPH and ORAC methods, and polyphenols from AT showed almost equal activity when compared with Trolox.Finally, by using natural product separation methods,4 compounds, including high content of rutin, and 3 glucosides of diterpenoids or triterpenoids had been purified and identified from the n-butyl alcohol layer of AT.To sum up, the research systematically analyzed and compared polyphenol content and antioxidant activity of AT from different varieties, different parts, different planting base and different month for the first time, as well as optimized conditions for extraction process of polyphenols from AT, and 4 compounds had been purified and identified from the n-butyl alcohol layer of AT, which provided a theoretical and material basis for the comprehensive utilization and development of the AT.