Hello everyone,
This is my first post here. I am trying to purify artemisinin from an ethanolic extract of Artemisia annua (sweet wormwood), and I ran into the the typical problem encountered by biochemists doing this procedure: removing the plant waxes without losing artemisinin. Most of the literature I have come across recomends using petroleum ether or hexane to defat ethanolic plant extracts. This would not work in my case because artemisinin happens to be very soluble in both of those solvents (in fact, hexane is used for industrial-scale production of artemisinin). I read a tip somewhere about using molten parafin wax, but that just removes the fats (as far as I know), not the wax. Am I wrong about this? Also, does the molten paraffin work well as a defatting agent? I read somewhere that heavier waxes aren't easily extracted by ethanol, is this true? Would defatting work with very cold petroleum ether (maybe the artemisinin won't be soluble enough at that temperature)?
Here is the rough plan of attack:
Filter ethanolic extract
Remove pigments with activated carbon
Defat with molten paraffin wax
Liquid-liquid extraction (either hot petroleum ether or isopropanol)
Crystallization
Adsorption chromatography (column with diatomite, elute with?)
If necessary, wash with activated carbon again
Recrystallize
Any comments on how to improve this?
Thanks for your time, I really appreciate any kind of feedback.
Sincerely,
Dr. Doom
