The backstory behind the 84-year-old Chinese pharmacologist's work is incredible: In 1967, Chairman Mao Zedong set up a secret mission ("Project 523") to find a cure for malaria. Hundreds of communist soldiers, fighting in the mosquito-infested jungles of Vietnam, were falling ill from malaria, and the disease was also killing thousands in southern China.
After Chinese scientists were initially unable to use synthetic chemicals to treat the mosquito-borne disease, Chairman Mao's government turned to traditional medicine. Tu, a researcher at the Academy of Traditional Chinese Medicine in Beijing, had studied both Chinese and Western medicine, according to a New Scientist profile, and was hand-plucked to search for an herbal cure. 
"By the time I started my search [in 1969] over 240,000 compounds had been screened in the US and China without any positive results," she told the magazine. But, she added: "The work was the top priority, so I was certainly willing to sacrifice my personal life."
And the work was absolutely painstaking. Along with three assistants, she reviewed thousands of traditional Chinese remedies, testing them in mice. One compound — from the leaves of the Chinese wormwood plant, Artemisia annua, seemed to vanquish malaria parasites in the blood. But they didn't find their fix just yet, according to New Scientist:
The team carried out further tests, only to be baffled when the compound’s powers seemed to melt away. Tu reread the recipe, written more than 1600 years ago in a text appositely titled "Emergency Prescriptions Kept Up One’s Sleeve". The directions were to soak one bunch of wormwood in water and then drink the juice.
Tu realised that their method of preparation, boiling up the wormwood, might have damaged the active ingredient. So she made another preparation using an ether solvent, which boils at 35 °C. When tested on mice and monkeys, it proved 100 per cent effective. "We had just cured drug-resistant malaria," Tu says. "We were very excited."

http://www.newsforage.com/2015/10/for-40-years-no-one-knew-this-woman.html