Study On Purification Of Iridoids From Figwort

The iridoids, the study target, was one of the chemicals in the traditional Chinesemedicine Scrophulariaceae, with a variety of pharmacological activities, such as anti-virius, anti-inflammatory, antioxidant, anti-tumor, anti-bacterial, anti-chromosomemutation, and promote pancreatic secretion, enhance immune function, in addition,iridoid compounds also had positive effect on the cardiovascular system, nervoussystem, digestive system. The iridoids in figwort was gradually widely researched,however, there still exited some limitations to be improved in the following aspects.First, the commonly used silica gel column chromatography had such shortcomings ashigh cost, inconvenient regrneration process. Second, the current methods usuallyseparated and purified just one, which meant low herbs utilization and waste. Therewere less research reports on application of macroporous resin to separate and purifyiridoids in figwort, the available ones mostly focused on the effects of factors asadsoption time and elution solvent to single indicator.In the sudy, the refluxing technology was used to extract the iridoids, such factorsas solvent polarity and temperature greatly influenced the extraction efficiency wereinvestigated. The results showed that the extraction efficiency can achieve the best whenherbs was obtained with water at70℃.The total iridoid glycosides were purified with macroporous resin, considering theharpagoside as the indicative ingredient of the total iridoid glycosides in figwort. Theresults showed that HPD100was the most suitable one in all five resins (AB-8, D101,HPD100, HPD450, NKA-II). The optimal parameters were sample extract pH of4,sample amount of10BV, adsorption time of48h, eluent of80%ethanol, pH of8,amount of6BV. Under the optimal conditions, the adsorption and desorption ratio ofharpagoside were95.58%and95.35%, respectively.Purified the total iridoids with macroporous resin, considering the catalpol as theindicative ingredient. The results show that the non-polar resin HPD100was the mostproper one in all five resins (AB-8, D101, HPD100, HPD450, NKA-II). The optimalparameters were sample extract pH of4, sample amount of10BV, adsorption time of56h, eluent of80%ethanol, pH of8, amount of6BV. Under the optimal conditions, theadsorption and desorption ratio of harpagoside were91.83%and94.44%, respectively. Desorbed the saturated resin with eluent of80%ethanol which pH of8、8.5、9，respectively, when the HPD100resin reached adsorption saturation with10BV extractwhich pH of4. Then analysised the desorption solution with HPLC, the results showedthat80%ethanol elution which pH of8.5may be the most suitable eluent, which canget the maximum amount of harpagoside and catalpol simultaneously, and suitable topurify total iridoids.