Separation And Purification Process Of Wedelolactone

Wedelolactone, one composition of eclipta, is one of the active polyphenoliccompounds. Pharmacological studies show that wedelolactone exhibits a broad rangeof biological activities, including the effect on cancer. Therefore, wedelolactone willbecome the focus of research in the purification of natural products and be widelyused in the field of food and medicine health. In this paper, the extractant of eclipta asthe raw material, the slica column chromatography-dilution Crystallization wasproposed to separate and purify wedelolactone.The wedelolactone was preliminarily separated from the extractant of eclipta byslica column chromatography. The optimal conditions were determined by the RSMexperiment, regarding the yield of wedelolactone as the target. For the experiment ofslica column chromatography, when the volume ratio of dichloromethane to methanolwas93.8:6.2, the volume ratio of acetic acid was0.49(when the volume ofdichloromethane and methanol was100mL, the volume of acetic acid was0.49mL.),the throughput of raw material was122.5mL. The result showed that the yield ofwedelolactone was83.2%.The optimal conditions of dilution crystallization process were obtained bysingle factor experiment, when the purity and yield of wedelolactone were regarded asthe target.The volume ratio of A to ethanol was5, the end point of temperature was5~10?, the crystallization time was4~8h and A was input by peristaltic pump. Theresults showed that the purity of wedelolactone was99.5%and the yield ofwedelolactone was93.3%. In order to reveal the active wedelolactone properties, thevitro antioxidative activity in vitro was studied. The antioxidative experimentindicated that: antioxidative activity value of0.1mg wedelolactone was equal to21.0mmol FeSO4. The scavenging activity of [DPPH·] and hydroxyl radical [·OH]experiment showed that the power of wedelolactone were better thanproanthocyanidins.In the present study, the solubility of wedelolactone in a binary solvent of waterand ethanol was determined at temperatures from278.15K to323.15K using adynamic method. The values of the solubility of wedelolactone in binary mixedsolvents increased with rising temperatures. For the mixtures, both of the values of standard molar enthalpy change and standard molar Gibbs energy change of solutionwere positive, which indicated that the process was endothermic and not spontaneous.Besides, Entropy-driving was found for almost all the mixtures.For scale-up process, we can get0.8325g wedelolactone (99.22%) from1kgeclipta. The dichloromethane-methanol solvent system was separated by batchextractive distillation to recycle dichloromethane. The results shown that the purity ofdichloromethane was99.5%and the recovery rate of dichloromethane was78.6%; thepurity of n-propanol was99.8%and the recovery rate of n-propanol was88.3%.The batch extractive distillation process was simulated by Aspen Plus.Two-column continuous extractive distillation process was also established. Forextractive distillation column B1, the number of plates was set to15, the mass refluxratio was1.4, the ratio of extractant to dichloromethane-methanol solvent was1.3, thefeed stage of raw materials was11, the feed stage of extractant was6, and D/F was0.406. For recovery column B2, the number of plates was set to20, the mass refluxratio was10.5, the feed stage of raw materials was11, and D/F was0.049. Underabove-mentioned conditions, the purity of dichloromethane was99.5%and therecovery rate of dichloromethane was99.8%; the purity of methanol was98.1%andthe recovery rate of methanol was94.2%; the purity of n-propanol was99.8%and therecovery rate of n-propanol was99.9%.