| Polygala is a kind of traditional Chinese herbs which is curatively effective for some diseases. Its main origins are Shanxi,Shaanxi,Jilin,Henan and other provinces.Polygala has been used as medicinal material for a month of Sundays and regarded as a top grade in Shennong's Classic of Meteria Medica.It is stipulate in PHARMACOPOEIA OF THE PEOPLE'S REPUBLIC OF CHINA that the medicinal materials of Polygala are the dry root of Polygala tenuifolia Willd or Polygala sibrica L. Polygala has broad pharmacological action in clinic.Pharmacological researches have demonstrated that the active ingredients of Polygala...saponin components posses the action of anti-bacteria, anti-inflammation,anti-oxide components ion,lower blood pressure,anti-cancer,delay aging,etc. So the extraction of saponin components from Polygala has become focus of research.In this paper,extraction of total saponins from Polygala was reviewed.Ultrasonic wave extraction of total saponins from Polygala was further studied.The main results were described as follows:1.Extraction ways of total saponins.Saponin components are usually extrcted with water or alcohols as solvent by heating-reflux or marinating extraction because they can easily dissolve into water,methanol and ethanol.Nowadays,ultrasonic extraction is also used to extract saponin.Some researches have demonstrated that the content of saponin is higher and the content of impurity is little if it was extracted with ethanol.In this paper,total saponins in Polygala was extracted with ethanol by heating-reflux and ultrasonic extraction and the two ways were compared with each other according to the quantitative determination by spectrophtotmetry.The content of total saponins extracted by ultrasonic was higher than by heating-reflux.The result shows that ultrasonic extraction is superior to heating-reflux.2.The optimum condition for extraction by ultrasonic method.There are many factors which affect the extracting rate of the effective content.So how to increase the extracting rate becomes a primary concern for Chinese herbs development and utilization.Effects of experimental conditions such as ultrasonic power,ultrasonic time,concentration of ethanol and ratio of solid to liquid were discussed in detail.Under single factor experimental condition,the optimal extracting condition was ultrasonic power 320W,ultrasonic time 30min,concentration of ethanol 75%and ratio of liquid to solid 1:20 respectively.Using total saponin content as a marker,the optimum extraction technology of Polygala was selected with the orthogonal experiment.The result showed that the optimum condition for extraction by ultrasonic method was as follows:extraction power was360W,extraction time was 40 minutes,concentration of ethanol was 75%and ratio of liquid to solid was 1:25. 3.Studies on kinetics of ultrasonic extraction.Renovation of traditional Chinese medicine by modern science and technology is a pressing mission confronted to us,one key step of which is to extract its effectual components,though Chinese medicine is treasure of the Chinese nation.The dynamical mechanics of extraction process is explored so that it has both theoretical and practical value to development of Chinese medicine and kinetics of chemical reactions.A kinetic equation for ultrasonic extraction process was presented based on the Fick's first law of diffusion and ultrasonic enhancement of solid-liquid diffusion.The relationships between concentration of total saponin and extraction time,size of particle,liquid-solid ratio were discussed when one of the factor was changed.The result showed that the relationships between ln c and ln P is linear on the whole but that between ln c and ln t is linear in a certain period of time. |
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