Study On The Extraction Of Salidroside And Process Of Macroporous Resin For Purification

This study takes the roots of Rhodiola crenulata as raw material and salidrosideas primary functional ingredient. We have optimized the processes by solvent refluxextraction and campared the removal of impurity between ethanol precipitating andflocculation agent clarifying methods. Further the purification processes of salidrosidewith macroporous adsorbent resins was also studied and the main results are asfollows:1. RP-HPLC method was taken as the major qualitative and quantitative method,and the measurement of salidroside was established. The result showed that theestablished HPLC method had good linearity and precision when salidroside was inthe range of0.056-0.168mg/mL and the recovery rate of salidroside was98.46%.Asa result, this method is suitable for salidroside analysis and the processes isoperational as well as repeatable.2. Salidroside in Rhodiola crenulata was extracted by solvent reflux method. onthe basis on single factor experiment, we optimized the extracting conditions and gotthe following results: the ratio of materials and solvent is1:7(g:mL), extractiontemperature is70℃, extraction times is2by distilled water reflux method and2hours every time. After centrifugating impurities were removed preliminarily fromsupernatant of extracts with high concentration of ethanol by means of precipitatingand the purity of Salidroside extracts from Rhodiola crenulata was0.29%, theextraction method was reasonable and simple.3. Three kinds of adsorption resins were selected from six different ones,according to adsorption and desorption properties for higher adsorption anddesorption rate, and finally SP-825, a nonpolar resin, was picked out for purificatingthe major active compound (salidroside). At the same time, its adsorption kineticsand thermodynamics for salidroside were studied and the experimental data werefitted to first-order, second-order models. The results showed that salidroside’sadsorption isotherm was well fitted to Langmuir equation and Freundlich equationand its adsorption kinetics can be described according to the second-order model.The sorption process was exothermic physical adsorption and the lower temperaturewas more favorable to adsorption. In a word, the optimum purification of salidrosideconditions were as follows: the concentration of salidroside in feed solution was5mg/mL, temperature of20℃,adsorption of4h,100mL of distilled water were added into for removing impurities along with240mL20%ethanol elution, Under theseoptimum conditions, the salidroside purity was27.86%and was96times of thatpre-purity,0.29%.