- Jan 07, 2019 -
Camptothecin is an alkaloid extracted from the camptotheca sinensis, which has anticancer effects and has been used in clinical practice. Camptothecin has special properties and is not easy to be extracted with acid, so it cannot be extracted with acid. It has inner fat ring in its structure and can be refined with acid-base method according to this characteristic.
Take 25 kg of the root powder, put it in a 200-liter extraction tank, add 150 liters of industrial ethanol, soak it in warm water for 4 to 5 hours, and maintain the internal temperature at about 50 degrees, and extract it five times in total. Combine extract, reduce pressure, concentrate to about 5 l, transfer to enamel plate to blow dry, residue, add 2 l water to soak.
The solids are filtered and washed with water four times, two liters at a time.The solid was extracted with chloroform, the chloroform was decompressed, and the residue was reflux with the same amount of methanol for one hour. Place overnight for filtration, collect solids, add a small amount of methanol, mix into a paste for filtration.
After drying add 10 times the amount of petroleum ether reflux, and wait for half an hour to do pumping filtration. Solid substance with a small amount of 1% sodium hydroxide solution grind into a paste, and then add equivalent to solid 35 times the amount of 1% sodium hydroxide solution and 25 times the amount of water, the mixture spinning liquid heated to about 70 degrees, maintain at this temperature for half an hour.
At this time, camptothecin is dissolved into sodium salt, which is filtered while hot. The filtrate is heated to 60 to 70 degrees, and 1% methanol is added to the total volume. Acidify the solution with hydrochloric acid to a ph of 2 and pour it over 3 times. The precipitation and recrystallization will result in camptothecin.
The camptothecin obtained above is crude and can be purified by alumina column chromatography.