Artemisinin (/ˌɑːtɪˈmiːsɪnɪn/) and its semisynthetic derivatives are a group of drugs used in the treatment of malaria due to Plasmodium falciparum. It was discovered in 1972 by Tu Youyou, who shared the 2015 Nobel Prize in Physiology or Medicine for her discovery. Artemisinin-based combination therapies (ACTs) are now standard treatment worldwide for P. falciparum malaria as well as malaria due to other species of Plasmodium. Artemisinin is extracted from the plant Artemisia annua, sweet wormwood, a herb employed in Chinese traditional medicine. A precursor compound can be produced using a genetically engineered yeast, which is much more efficient than using the plant.