Artemether
Artemether, isolated from Chinese-Vietnamese plant Artemisia annua L., locally called "qing hao", is used to treat fever and malaria. It is a white crystalline powder with a bitter taste; practically insoluble in water, soluble in chloroform, acetone, and alcohols. Its chemical designation is (+)-(3-alpha,5a-beta,6-beta,8a-beta, 9-alpha,12-beta,12aR)- decahydro- 10-methoxy- 3,6,9-trimethyl- 3,12-epoxy- 12H-pyrano (4,3-j)-1,2-benzodioxepin. Malaria is one of leading re-emerging infectious disease due to murative malarial parasite developed resistance to chloroquine. Sulfadoxine-pyrimethamine is an alternative can be used in the treatment of the disease resistant to chloroquine, but resistance to sulfadoxine- pyrimethamine has been reported also in some areas. Artemisinin is an alternative used in areas where the disease has become highly resistant to sulfadoxine-pyrimethamine. Dihydroartemisinin, its methyl ether (artemether), its ethyl ether (arteether) and its hemisuccinate ester (artesunate) are known as more effective than its parent material - artemisinin. But their activity decreases after one or two hours. For simultaneous administration to counter the drawback, combination therapy of artemisinin along with lumefantrine, mefloquine, amodiaquine, sulfadoxine, and pyrimethamine is useful. The term of artemotil refers to the pure beta-epimer of arteether. Artemisinin is a peroxide-bridged sesquiterpene lactone compound which has no N atom, unlike quinine class anti-malarial drugs. The characteristic peroxide lactone structure is indispensable for anti-malarial activity. This structure is also under the research for the treatment of cancer.