Chinese researchers have developed a new technology to produce artemisinin, a top malaria treatment, on a large scale.
Sweet wormwood was used in ancient Chinese therapy to treat various illnesses, including fevers typical of malaria. Nearly five decades ago, Chinese scientists identified its active ingredient, artemisinin.
In 2005, the World Health Organization recommended artemisinin-based Combination Therapies (ACTs) as the most effective malaria treatment available. Global demand for artemisinin increased, but the quality and supply have not been stable.
According to researchers from the Institute of Process Engineering (IPE), Chinese Academy of Sciences, due to its complex structure, artemisinin is currently difficult and not economically feasible to chemically synthesize.
The traditional industrial method to produce artemisinin is to treat sweet wormwood leaves with organic solvents like petroleum ether.
The extraction process is long, energy consumption is high and productivity is low.
In the study, the IPE researchers proposed enhancing contact between the solvent and the leaves by reflux to speed up the artemisinin extraction. The extraction time was reduced from seven hours to four and a half.
After treating sweet wormwood leaves with solvents, they optimized the evaporation process with a thin film evaporator, an apparatus that provides a continuous evaporation process, especially for heat-sensitive products, to retrieve the solvents.
Compared to the traditional process, the time it takes to produce the artemisinin concentrate is reduced by 87.5 percent.
Meanwhile, the purity of the final product is increased to more than 99 percent, and energy consumption is also reduced.
The new technology puts the recovery of the solvents at 99.9 percent, while energy consumption per ton of artemisinin drops by 43 percent and the product purity rises to higher than 99 percent, said Wang Hui from the IPE.
"This technology solves the main shortcomings in the traditional artemisinin production process and could also provide ideas for other natural products production," said Zhang Suojiang, IPE director.
The new technology has been deployed at a plant of Tianyuan Biotechnology in Yuzhou in Henan province.
Jiang Hongge, manager of the company, said that the production line using the new technology had been in stable operation for a year at the plant with an annual production of 60 tons of artemisinin.
Sixty tons of artemisinin corresponds to about 150 million treatment courses of ACT.
The WHO says an estimated 409 million treatment courses of ACT were procured by countries in 2016.
Artemisinin produced at the plant has been sold to India, Sudan and other developing countries. The company also plans to build artemisinin production lines in Ghana. (Xinhua)
International Cooperation Office, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China.