3,12-Epoxy-12H-pyrano[4,3-j]-1,2-benzodioxepin, decahydro-10-methoxy-3,6,9-trimethyl-, (3R,5aS,6R,8aS,9R,10S,12R,12aR)- 71963-77-4 AIDS-008344 AIDS008344 Artemether Dihydroartemisinin methyl ether NSC665970 qinghaosu