Study On The Process And Mechanism Of Saponins By Pressurized Solvent Extraction

Pressurized solvent extraction (PSE) was applied for saponins extraction fromTraditional Chinese Medicines, and the mass-transfer mechanism was investigated.Main contents and experimental results are as follows:1. A method to extract9Chinese medicines (Radix Sanguisorbae, RadixPulsatillae, Leguminosae, Dioscorea nipponica Makino, Polygonatum sibiricum,Radix Bupleuri, Anemarrhena asphodeloides, Glycyrrhizae and Ophiopogonjaponicus) using PSE was described and the conventinal reflux extraction (RE) wasperformed for comparison study. The result showd that the yields, the antioxidantactivity and the antibacterial activity of the extract from pressurized solvent extractionwere significantly higher than that of traditional reflux extraction.2. As an alternative of traditinal extraction mathod, PSE of saponins from RadixSanguisorbae and Radix Pulsatillae was studied. The effects of several factors ofpressurized solvent extraction including extraction solvent, temperature, pressure,extraction time were optimized by univariate approach coulped with centralcomposite design in order to obtain the highest extraction efficientcy. The optimumconditions for saponins from Radix Sanguisorbae were as follows: distilled waterused as extraction solvent, material-liquid ratio at1:10, extraction temperature at110℃, extractpressure at2.80kg/cm2, extracting time at41min. Based on the parametersabove, the yields of saponins steadied at4.29%. The optimized process parametersfor saponins from Radix Pulsatillae were as follows: distilled water used as extractionsolvent, material-liquid ratio at1:10, extraction temperature at118℃, extractpressure at2.70kg/cm2, extracting time at33min. Based on the parameters above, theyields of saponins steadied at6.72%.3. Effects of extraction methods (RE, ultrasound-assisted extraction(UAE),microwave-assisted extraction(MAE) and PSE) were investigated for effective recovery, antibacterial activity and antioxidant activity of saponins from RadixSanguisorbae and Radix Pulsatillae. Scanning electron microscope images of theplant cell after extrcted by RE, UAE, MAE and PSE were obtained to provide visualevidence of the extraction effect.. The experimantal results indicated that PSE wassuperior in terms of high extraction yield, antibacterial activity and antioxidantactivity.4. Preliminary study of the mass-transfer mechanism and the influence oftemperature on the extraction rate of pressuried solvent extraction were researched.The result was that the kinetics model of pressurized solvent extraction technologywhich extracted saponins from Radix Sanguisorbae and Radix Pulsatillae was basedon the assumption of a mechanism of a second-order kinetic equation that wasdeveloped to predict the concentraction of saponins with various temperatures andtimes.Pressurized solvent extraction technology with time-saving, high efficiency, lowimpurities, low energy consumption and environmentally friendly features had openedup new avenues for the modemization of Chinese medicines.