NMR and conformational studies of the antimalarial drug arte-ether

The H-1 and C-13 NMR spectra of the antimalarial drug arte-ether (a derivat ive of qinghaosu) have been obtained and stereospecific assignments made us ing standard one- and two-dimensional techniques. Proton homonuclear spin-c oupling constants were quantified from J-resolved and E.COSY experiments an d confirmed that the solution conformation of arte-ether is similar to that of the reported crystal structure of artmether. A conformational model was generated using AM1 semi-empirical energy calculations, and was consistent with both the measured spin-coupling constants and experimental NOE data.