Antimalarial activities of 25 derivatives of artemisinine against chloroquine-resistant plasmodium berghei

The antimalarial activities of 25 derivatives of artemisinine, including dihydroartemisinine, 13 ethers, 6 esters and 5 carbonates, were compared. Each compound, dissovlved in tea seed oil, was injected intramuscularly into mice infected with the chloroquine-resistant strain of Plasmodium berghei. Adopting SD90 as a comparision criterion, the results showed that many of the derivatives were much more potent than artemisinine. They are SM224(O-methyl dihydroartemisinine, beta) in the ethers, SM241 (butyryl dihydroartmisinine, alpha) and SM108 ( propionyl dihydroartmisinine, alpha) in the esters, and SM242(propoxy carbonyl dihydroartmisinine, alpha), SM275( ethoxy carbonyl dihydroartmisinine, alpha+beta), SM223 (ethoxy carbonyl dihydroartmisinine, alpha ) and SM 276 ( phenoxy carbonyl dihydroartmisinine, alpha+beta) in the carbonates. Their chemical structures and values of SD90 are presented in Table 1.