Project Lead(s): Jack Njiru
Malaria is still a major global health problem, with about 198 million cases in 2013 and an estimated 585,000 deaths, mostly among African children.
Artemisinin, extracted from the plant Artemisia annua, in combination with other drugs known as Artemisinin Combination Treatments (ACTs), is now the front-line treatment for malaria.
A stable, reliable supply of artemisinin at an affordable cost is a critical requirement for malaria treatment.
In the process of producing natural artemisinin, every ton of Artemisia leaves extracted yields 7 to 8 kilos of artemisinin and 30 to 40 kilos of waste (primarily waxes), which also contains about 10% dihydroartemisic acid (DHAA and AA).
Although not yet carried out commercially, DHAA and AA can be isolated from the waste streams and converted to artemisinin, increasing the recovery of artemisinin by a further 2 to 3 kilos of artemisinin per ton of raw material processed.
The specific objectives of this project were to demonstrate the commercial viability of:
1. Recovering DHAA and AA from the existing artemisinin processing waste streams
2. Converting it to artemisinin by a novel photosynthetic process
3. Assessing the potential benefit of selecting strains of Artemisia annua that have above-average content levels of DHAA and AA, in addition to high levels of artemisinin.
The project team was able to quantify the amounts of DHAA and AA in the raw material, and in the factory waste streams.
They successfully recovered DHAA and AA from the waste streams at close to the expected level and developed a process to convert AA to DHAA.
Test runs to convert DHAA to artemisinin have been conducted and, despite delays, work is ongoing.
Field trials were done with different varieties of Artemisia annua on three sites and, while the results are not conclusive, they do suggest variability in the active ingredients between the different varieties.
The team has also identified a source of DHAA produced from bacterial fermentation, which could be converted to artemisinin, using the same conversion process and largely the same equipment.
This could potentially supply a far greater quantity than that generated from the waste streams.
The team has applied for Phase II Transition To Scale funding to continue the project.