| There is aboundant of camellia seed resource in China which contains a variety of high economic substances, including teasaponin (TS) about 10%20%. There have great significance for full utilization of camellia seed which of the teasaponin is widely used in presticide, food stuff, pharmaceutical and industry. Using camelilla cake as raw material, the process of extraction and purification of teasaponin were investigated in this thesis. Structure, property and antibacterial activity of teasaponin products were also identified.The results and most of the content as follows:(1) Using green tea leaves as raw material, the effect of hydroxyl free radical scavenging activity of tea polyphenols (TPs) by ultrasound extraction was investigated. TPs were extracted by ultrasound-assisted extraction, hot relfux extraction, enzymatic extraction and combination of cellulase hydrolysis and ultrasound-assisted, respectively, and the resultant products were measured for their physico-chemical properties and hydroxyl free radical scavenging activity. The results showed that the extraction efficiency and product purity resulting from hot reflux extraction at 90℃were higher than those resulting from other three methods, but the product obtained had lower hydroxyl free radical scavenging activity than that obtained at lower reflux temperatures. Ultrasound-assited extraction at room temperature exhibited better extraction efficiency and product purity, and hydroxyl free radical scavenging activity of the product obtained was higher than that of the products obtained by other three methods. Combination of ultrasound-assited extraction and cellulase hydrolysis gave better extraction efficiency; however, the purity and hydroxyl free radical scavenging activity of the product obtained were both lower than those of the product obtained by ultrasound-assited extraction alone.(2) In this study, the total content of teasaponin was measured by the determination of assay method which was 20.93%. Extraction of teasaponin was used by ultrasound assisted ethanol-water, the extraction influence of ethanol concentration, liquid to solid ratio, ultrasound power, ultrasound times, extraction temperature and pH value were investigated. The orthogonal design of L9(34) was used in the experiment to obtain the optimum extraction parameters. The result was obtained as follows: liquid to solid ratio was 12:1, ethanol concentration was 60%, extraction temperature at 50℃and pH value 9. The extraction efficiency that was the content of teasaponin in extract of TS was 18.63% at the conditions listed above. (3) A new one-step of extraction-purification of teasaponin was proposed. Using extract by ultrasound assited ethanol-water as material, saturated Ca(OH)2 solution as TS precipitation agent, which of the precipitation reaction product is (R-sap)2Ca , collect the precipitation product and add conversion agent of NH3HCO3 to release the TS. The optimum precipitation and conversion parameters were obtained as follows: the ratio of Ca(OH)2 to teasaponin(g/g) was 1, precipitation stirring reaction time was 1.5 h, precipitation storage time was 1h, the ratio of conversion agent to (R-sap)2Ca(g/g) was 2, conversion temperature was 70℃, conversion time was 1.5 h. The yield of teasaponin was 71.28% and the product purity was 73.44% under these conditions.(4) The process of two extraction-purification methods of teasaponin, including water extraction-precipitation and ethanol extraction-precipitation. The extraction efficiency, yield of teasaponin, product purify and antibacterial activity were inverstigated. The results showed that the extraction efficiency, yield of teasaponin, product purify and antibacterial activity obtained by ethanol extraction-precipitation were better than that obtained by water extraction-precipitation. The products were pentacyclic triterpene saponin, identified by UV spectrogram, infrared spectrum and melt point.(5) Through the teasaponin inhibitory effect of three bacterial include staphylococcus aureus, E.coli and P. aeruginosa in this study. The results showed that, the inhibitory effect of S.aureus was significantly increased with the increase of solution concentration of TS. It had the strongest inhibitory activity when the solution concentration at 60mg/mL. When the solution concentration was less than 40mg/mL, the inhibition efficiency of E.coli and Pseudomonas aeruginosa was less than 5%, almost has no inhibitory activity. When the solution concentration was higher than 50mg/mL, it obtained weak inhibition. |
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