USE OF CELL-FREE SYSTEMS IN THE PRODUCTION OF THE POTENT ANTIMALARIAL, ARTEMISININ

Artemisinin (qinghaosu, QHS), 1, a compound from the traditional Chinese medicinal herb, qinghao, Artemisia annua L. (Asteraceae), has shown high potential in the treatment of multidrug resistant forms of Plasmodium species, especially the most virulant P. vivax and P.falciparum. Clinical trials and treatments conducted in the Peoples' Republic of China has shown it to be, by far, the safest and most effective antimalarial. The work presented here uses crude leaf homogenates of A. annua to convert the more easily available precursor, artemisinic acid, 2, to artemisinin by these cell-free enzymes. A novel procedure using GC-CIMS to quantitate the results has been developed. A hypothetical pathway for the conversion of artemisinic acid to the target drug through the intermediacy of arteannuin B, 3, another metabolite of the same plant, is described.