How to extract paclitaxel from Taxus chinensis

Taxol is the main active component of Taxus chinensis and a natural secondary metabolic derivative with terpenoid ring structure. Because of its low content, many structural analogues, high purity requirements, easy transformation in the separation process, and difficult extraction, separation and determination. How to extract taxol with low cost and simple process, separate taxol from its analogues, obtain high-purity taxol products and determine them accurately has become a research hotspot.

Commonly used extraction methods include: methanol organic solvent extraction, ethanol organic solvent extraction and so on. Extraction can be divided into primary extraction and secondary extraction, in which the choice of solvent has an important influence.

Commonly used purification methods include: normal phase column chromatography and reverse phase chromatography, including normal pressure and low pressure column chromatography, dry column chromatography and some advanced separation methods such as high-speed countercurrent chromatography.

At present, the extraction methods of taxol are mostly to extract Taxus raw materials with organic solvents for many times, recover the leaching solution, then extract with organic solvents, and crystallize after chromatographic separation to obtain taxol. The biggest problems of these methods are low extraction yield, expensive equipment, huge waste of resources, increased production costs and big environmental problems.

The specific extraction steps are as follows: pulverizing raw materials of Taxus chinensis, sieving with 100-200 mesh sieve, adding 5- 10 times of water and 0. 1% glacial acetic acid, and adding cellulase for ultrasonic enzymolysis for 2-5 hours; Adding an equal volume of organic solvent, and performing ultrasonic extraction for 0.5-2 hours; Stan, filtering, separate, extracting that water phase with an organic solvent for 2-3 times, and combine the organic phases; Removing organic solvent under reduced pressure, mixing the obtained extract with neutral alumina of equal mass, passing through silica gel or alumina chromatographic column of 200-300 mesh, eluting with petroleum ether and ethyl acetate to remove fat-soluble impurities, eluting with mixed solution of ethanol and ethyl acetate, monitoring, and collecting ethanol and ethyl acetate fractions; Removing ethanol and ethyl acetate under reduced pressure, sequentially passing the obtained crude product through a weakly basic resin column and a strongly basic resin column, and eluting with a mixed solution of dichloromethane and acetone to obtain a pure product; The pure product is refined by recrystallization.