ANTIMALARIAL ACTIVITY OF NEW ETHERS AND THIOETHERS OF DIHYDROARTEMISININ

Various ethers and thioethers of dihydroartemisinin were prepared by t reating dihydroartemisinin with hydroxy alkyl, substituted phenol, hyd roxy aralkyl, hydroxy alkynyl and hydroxy heteroalkyl or thiols in the presence of BF(3)Et(2)O. The thioethers 64 and 65 were further oxidis ed to the respective sulfoxides. These derivatives were tested in the Plasmodium berghei K-173-infected mice and some active compounds were tested in chloroquine-resistant P yoelii nigeriensis (NS)-infected mic e. Initially the compounds were administered subcutaneously and subseq uently by the oral route. The antimalarial activity of the compounds 2 2, 23, 36, 66 and 79 were found to be comparable to that of arteether when tested in the K-173-infected mice. These compounds also showed ac tivity in the P y nigeriensis (NS)-infected mice.