| This study took Camptotheca acuminate as material and studied the dynamic change of camptothecin and hydroxycamptothecin content in leaves of Camptotheca acuminate and extraction and purification of camptothecin from leaves of Camptotheca acuminate.1. The dynamic changes of camptothecin and hydroxycamptothecin content in leaves of Camptotheca acuminate1) The dynamic changes of camptothecin and hydroxycamptothecin content in leaves of Camptotheca acuminate in different monthsThis study took a Camptotheca acuminate tree under Jinyun Mountains as material and studied the dynamic changes of camptothecin and hydroxycamptothecin content in leaves of Camptotheca acuminate. The result showed that the dynamic changes of camptothecin and hydroxy camptothecin content in young leaves is great different from that of matural leaves. The maximum content of camptothecin and hydroxycamptothecin was reached in late July and May in young leaves, but reached in late September and April in matural leaves.2) The effect of overshadow on camptothecin content of Camptotheca acuminate seedingsThis study took Camptotheca acuminate seedings as material and studied the effect of overshadow on photosynthesis and accumulation of camptothecin in Camptotheca acuminate seedings. The results showed that overshadow was benefit for accumulation of camptothecin, and camptothecin content increased while light intensity decreased.2. Study on extraction and purification of camptothecin from leaves of Camptotheca acuminate1) In the studies of extracting camptothecin, we contrasted the effect of different extraction solvent,different extraction methods,different time of ultrosonic extraction,extraction times and extraction solvent on extraction rate of camptothecin. The results showed that ethanol concentration 70％was better, the best ultrasonic time was 30 min, the best extraction solvent was chloroform and only needed extracting twice.2) We contrasted the effect of macro porous absorbing resins and silica-gel column chromatography on extraction rate of camptothecin. The results showed that the purity of camptothecin extracts increased from 0.66％to 11.05％and 10.8％after one purification, recovery of camptothecin was 55.3％and 95.5％.3) The camptothecin extract purified after silica-gel column chromatography was refined by high-speed counter-current chromatography (HSCCC) with the solvent system composed of n-hexane-ethyl ecetate-ethanol-water(3.5: 6.5: 3.5: 6.5,v/v) after one operation, the purity of camptothecin increased from 10.8％to 98％, and the recovery was 95％.4) Detection ofbioactivity of camptothecin sample after refining by HSCCCWe detected the bioactivity of camptothecin sample after refining by HSCCC via MTT mothod. The result showed that the refined camptothecin sample could induce apoptosis of Hela cell, and its IC50 was 16.7ng·mL-1, the same as camptothecin standard.
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