ARTESUNATE INTERACTION WITH HEMIN

Artesunate is an important new antimalarial drug. The interaction of a rtesunate with hemin was investigated by electrochemical methods and U V spectroelectrochemistry (UV-SEC). Artesunate underwent an entirely i rreversible reduction at ca. -1.27 V (vs. Ag/AgCl) on the glassy carbo n electrode. Hemin can catalyze the decomposition of artesunate. In th e presence of concentration of hemin as low as 2x10(-8) M, the cathodi c overpotential of artesunate was reduced ca. 680 mV (E-pc = -0.59 V v s. Ag/AgCl). UV-SEC experiments further confirm this process. UV spect ra show that the decomposed products of artesunate have absorption beh avior similar to artesunate. These results indicated that artesunate m ight undergo the identical antimalarial mechanism as its parent compou nd Qinghaosu, and hemin plays a catalyst role in the process of action of Qinghaosu-type antimalarial drugs. (C) 1998 Elsevier Science S.A.