Ultrasonic Assisted Extraction Plantain Composition Process Optimization And Component Separation

It has been a main approach to extract medication from natural plants. Plantain is an ancient traditional Chinese drug which has been widely used in clinic applications from ancient time. However, most of the studies are based on crude extracts and hasn't reached active constituents yet.It is supposed to get three objects in this study: 1) optimize the extracting process of plantain in assistant of ultrasonic; 2) separate all the constituents extracted from plantain; 3) characterize new constituents from plantain. This paper is divided into four parts:Chapter one: It is a review of research progress in different aspects of plantain, including medicinal works, crude drug, components, pharmacy, and extraction means.Chapter two: The optimization of the ultrasonic- assistant extracting process was defined by observing extracting time, temperature and the power of the ultrasonic through single-factor experiments and direct-cross experiments. Solvent-extraction combined with ultrasonic was used with ethanol as the extracting agent. The result shows that the main factor of the ultrasonic-assistant extraction of plantain polysaccharide is the power of the ultrasonic, then is the extracting temperature, and the time of ultrasonic pretreatment. The optimum scheme is 70℃,2 hours of ultrasonic pretreatment and 400w of the ultrasonic power.Chapter three: The medicine constituents were gotten through the process optimization with silica gel as stationary phase and PE & EA as solvents. Then the elution was concentrated and PE, acetone and butanol were added. Further, the material extracted was separated with the PE extraction and with column chromatography again. The separating effect could be seen on thin layer of chromatography. In the end, 280 fractions were gotten and after purification 129 different fractions were left. After re-crystal of large amount of fractions, 40 bottles of more pure fractions were got.Chapter four: The newly-extracted constituents were characterized mainly. Two new constituents have been discovered in the 40 bottles of more pure components, one is white acicular crystal and the other is green. After further purification, UV, IR and HNMR were used to characterize the two constituents. The result shows that two new constituents have been discovered, one of which hasn't been reported yet. The white crystal is a kind of strides saponins, while the green is a new one. It was found that the new constituents has symmetric structure, containing—OH,C=O,C=C-O,C-O-C and aromatic groups.