Deoxyarteannuin B, dihydro-deoxyarteannuin B and trans-5-hydroxy-2-isopropenyl-5-methylhex-3-en-1-ol from Artemisia anuua.

The amorphane sesquiterpenes, deoxyarteannuin B and dihydro-deoxyarteannuin B, were isolated from Artemisia annua and their structures mainly determined by two-dimensional NMR spectoscopic analyses. The irregular monoterpene, trans-5-hydroxy-2-isopropenyl-5-methylhex-3-en-1-ol, was also characterized in the same way, and its structure was confirmed by synthesis from lavandulol. All of these natural products are suggested to be formed by autoxidation reactions. Full assignments of the 1H and 13C resonances for the known natural products epi-deoxyarteannuin B and isoannulide, determined by the same methodology, are also reported.