Study On Extraction And Separation Technology Of Chlorogenic Acid Content Variation In Jerusalem Artichoke(Helianthus Tuberosus L.)Leaves From Different Producing Areas

Jerusalem artichoke (Helianthus tuberosus L.), an perennial plant, originated from North America. It was an Angiosperm of the Compositae family. Many kinds of chemical component were found in the leaves, they were mainly phenolic compounds and sesquiterpene compounds.Of all the components in the leaves, chlorogenic acid was the most physically active one. Chlorogenic acid showed biological activities in anti-bacterial, phlogistic, detoxification, anti-bacterial, antimutagenesis, liver-protective, oxidant, which promising a prospect for future development.In recent years, studies about chlorogenic acid focused on the extraction, separation, content measurement and medical function in Eucommia, honeysuckle and some other plants, but there were fewer reports about chlorogenic acid in Jerusalem artichoke. The research set up the method about the measurement of chlorogenic acid in Jerusalem artichoke leaves by HPLC, optimized the extraction methods, and separated the chlorogenic acid by macroporous resins.1. Method development of chlorogenic acid in Jerusalem artichoke leaves by HPLC.HPLC conditions:column:Agilent C18(4.6X150mm,5μn);detection wavelength:327nm:mobile phase:1%water-phosphoric-ACE (87:13);flow rate:1ml/min;column temperature:30℃. The method was simple, rapid, accurate and suitable for the measurement of chlorogenic acid in Helianthus tuberosus leaves.2. The extraction technology of chlorogenic acid from Helianthus tuberosus leaves was studied by discussing the effects of extraction methods, extraction reagents, extraction temperature, time, and the ratio of material solution on the content of chlorogenic acid. Based on the single factor experiments, the extraction technology of chlorogenic acid from Helianthus tuberosus leaves was optimized by orthogonal design. The optimal technology were:reflux extraction,70%methanol concentrations as extraction reagent,80℃extraction temperatures,2.5h extraction time and the ratio of material/solution was1:25. The results provided scientific basis for chlorogenic acid extraction from Helianthus tuberosus leaves.3. The separation technology was studied by macroporous resins. The static adsorption rate and desorption rate were examined to determine the better resin. The research discussed the influence of adsorption rate by sample concentration, pH and flow rate, and the effects of desorption rate by ethanol concentration and elution rate. NKA-2showed both better static adsorption rate and desorption rate. The optimum adsorption conditions were:2.0ml/min as the flow rate,0.1mg/ml as the chlorogenic acid concentration and pH2.0. And the optimum desorption conditions were:40%ethanol and0.5ml/min as the elution rate. Chlorogenic acid can almost be washed down by50ml ethanol elution.4. Determination of the chlorogenic acid content in3varieties and3growth periods in Dafeng area, and2varieties in Daqing area were conducted by HPLC. The chlorogenic acid content in Nanyu No.10of Dafeng area was higher than that of others in3growth periods. The chlorogenic acid content in Jerusalem artichoke leaves from Daqing area was higher than the leaves from Dafeng area. Nanyu No.1in Daqing area had the highest chlorogenic acid content,2.139%DW. The test results showed varietal differences, growth period differences as well as ecological differences of chlorogenic acid content in Jerusalem artichoke(Helianthus tuberosus L.) leaves. The study provided evidences for future exploitation on Jerusalem artichoke leaves utilization.