Mann Taxus Paclitaxel Extraction Separation Process And The Determination

The extraction and primary isolation of taxol from the leaves andbranches of Taxus media was studied systematically in this paper. Somespecial difficulties exist in this process because leaves and branchescontain a large amount of impurities such as wax, pigment that may beextracted during the separation as well, thus, the process becomes moredifficult. To this point, the pre-treatment method which combinedn-hexane extraction with basic-solution extraction, which wiped out theapolar and the mildly polar compound such as wax firstly, then washedoff the superior polar impurities. The impurities may be wiped out about80％in this way, so the efficiency of sample treatment was improvedgreatly.Extraction effect of extractive solvent such as ethanol,methol,propanone,Trichloromethane was studied here.Considerating the purity oftaxol in extraction,exraction rate and cost, ethanol was picked out asextractive solvent. Optimization selection in extraction conditions oftaxol was follows: heating extraction three hours in 60℃, ratio offeed-stock weight to the volume of solvent is 1:20, the first extractionratio was 74.80％and extraction ratio reached 99.21％by threeextractions.Ultrasonic extraction and Soxhlet extraction was performedand compared. Ultrasonic extraction procedure was follows: ratio offeed-stock weight to the volume of solvent is 1:20; extraction 40 min atroom temperature. Extraction rate reached 98.44％by two extractions.Compared with common extraction, ultrasonic extraction was performedat lower temperature and spent less time. Due to high extractiontemperature,taxol may be stereoisomer or degrade, so extraction rate bySoxhlet extraction was low,Experiments of purification for taxol were completed by silica gelchromatographic column and AB-8 macroreticular resin chromatographiccolumn. For the silica gel column chromatography process,suitableoperating conditions was selected by optimization of the elution rate andthe ratio of hight to diameter of column, chromatographic procedure wasfollows: the column size wasΦ25×40 0mm; feed-stock weight was0.5-0.75g; elution rate was 1-1.5 mL/min, the eluting reagent was 3BV trichloromethane and 3BV 3％methanol trichloromethane solutions.Thepurity of taxol reached 5.82％with the recovery of 98.78％after the onesilica gel chromatographic step.For the AB-8 macroreticular resin chromatography process,chromatographic procedure was follows: the column size wasΦ25×400mm; elution rate was 1.5 mL/min; the eluting reagent was 3BV 30％ethanol, 3BV 50％ethanol and 3BV 70％ethanol. The purity of taxolreached 3.25％from 0.20％with the recovery of 99.36％after the oneAB-8 macroreticular resin chromatographic step. The eluting reagent inthe second chromatographic procedure was 3BV 60％ethanol and 3BV70％ethanol.After the second chromatographic step, The purity of taxolreached 18.43％from 3.25％with the recovery of 96.46％.Reversed phase HPLC was used to determine and analyze the amountof taxol. The analysis condition of taxol was as follows:C18 column,methanol:water(65:35 v/v) as mobile phase, UV detector at 227nm,flowrate is 0.7mL/min. The external standard method was employed forquarlitative and qualitative analysis. The result shows that the taxolcontent in Taxus media is 0.0126％and RSD is 1.46％.