Leaf extraction

Malaria is one of the world’s most widespread diseases, infecting over 400 million people each year and causing about three million deaths.

The most effective drug against malaria is artemisinin, an extract from the herb Sweet Wormwood; most patients taking it improve within 24 hours.

But artemisinin has a big drawback – it is produced using the petroleum-derivative hexane, a toxic and potentially explosive substance which damages the environment.

Now a team of specialists at Bath University has identified three extraction processes that can compete economically with the traditional hexane method, as well as being better for the environment.

The research team found that technologies using supercritical carbon dioxide, hydrofluorocarbon and ionic liquids, all of which are non-flammable solvents, gave faster extraction times and a more complete extraction of the useful substances in the leaf.

These solvents are also considerably safer, with no risk of explosions, and are also much greener, having a lower environmental impact.