চীনা চিকিৎসা বিজ্ঞানী তু ইউইউ কোন সালে আরটেমিসিনিন আবিষ্কার করেন ?
"Artemisia annua" extract, called "qinghao", was described vividly in the fourth-century Chinese physician Ge Hong's book "Zhouhou Beiji Fang" ("The Handbook of Prescriptions for Emergencies") as a treatment of malarial fever. Tu Youyou and her team were the first to investigate. In 1971 they found that their extract from the dried leaves (collected from Beijing) did not indicate any antimalarial activity. On careful reading of Ge Hong's description they changed their extraction method of using fresh leaves under low temperature. Ge Hong explicitly describes the recipe as: "qinghao, one bunch, take two sheng [2 × 0.2 l] of water for soaking it, wring it out, take the juice, ingest it in its entirety". They found that only the fresh plant specimen collected from Sichuan province would yield the active compound. They made the purified extract into tablets, which showed very low activity. They soon realized that the compound was very insoluble, and hence, made it in capsules. On 8 March 1972 they reported successful treatment of malaria in experimentally infected mice using the new extract. In August 1972 they reported a clinical trial in which 21 malarial patients were cured. In 1973 scientists at the Yunnan Institute of Materia Medica and Shandong Institute of Traditional Medicine and Materia Medica obtained the antimalarial compound in a crystalline form gave the name "huanghaosu" or "huanghuahaosu", which was eventually renamed "qinghaosu" (yet later to be popularised as "artemisinin", after the botanical name). (The chemical structure of artemisinin was worked out only in 1975, and published in 1977.) The same year Tu synthesized the compound dihydroartemisinin from the extract. This compound was more soluble and potent than the native compound. Other artemisinin derivatives were subsequently synthesized by other workers, of which the most important are artemether and artesunate. All clinical trials by this time confirmed that artemisinins are more effective than the conventional antimalarial drugs, such as chloroquine and quinine. They are now recognised not only as the most potent, but also as the safest and rapidly acting antimalarial drugs.
1972