Elucidation of the Enzyme-Catalyzed Endoperoxide Forming Step in Artemisinin Biosynthesis

Artemisinin is the endoperoxide-containing plant natural product used to treat malaria, a deadly disease that has killed 445,000 people in 2016 - 90% of these deaths were in Africa. The current industrial production of artemisinin employs a semi-synthetic approach, which involves the microbial fermentation of yeast containing the plant genes to produce the biosynthetic precursor, artemisinic acid, followed by four chemical transformations to yield artemisinin. However, this current approach is not cost-effective, and there is a critical need to efficiently provide the global supply of artemisinin. Through our preliminary studies, we have identified the potential enzyme involved in endoperoxide formation from the biosynthetic precursor, dihydroartemisinic acid, to form artemisinin. This research proposal will clarify the enzymatic conversion from dihydroartemisinic acid to artemisinin. Knowlege of the true biosynthetic pathway to artemisinin will enable the development of an efficient method to mass produce artemisinin either through: (1) a complete microbial fermentation approach or (2) an enzyme-immobilized production to provide the global supply of artemisinin.