Interaction between artemisinin and heme. A Density Functional Theory study of structures and interaction energies.
Malaria is an infectious disease caused by the unicellular parasite Plasmodium sp. Currently, the malaria parasite is becoming resistant to the traditional pharmacological alternatives, which are ineffective. Artemisinin is the most recent advance in the chemotherapy of malaria. Since it has been proven that artemisinin may act on intracellular heme, we have undertaken a systematic study of several interactions and arrangements between artemisinin and heme. Density Functional Theory calculations were employed to calculate interaction energies, electronic states, and geometrical arrangements for the complex between the heme group and artemisinin. The results show that the interaction between the heme group and artemisinin at long distances occurs through a complex where the iron atom of the heme group retains its electronic features, leading to a quintet state as the most stable one. However, for interaction at short distances, due to artemisinin reduction by the heme group, the most stable complex has a septet spin state. These results suggest that a thermodynamically favorable interaction between artemisinin and heme may happen.
Araújo
Jocley Queiroz
JQ
Programa de Pós-Graduação em Química Orgânica, Universidade Federal Fluminense, Outeiro de São João Batista, s/n, 24020-150, Niterói, RJ, Brazil.
Carneiro
José Walkimar de Mesquita
JW
de Araujo
Martha Teixeira
MT
Leite
Franco Henrique Andrade
FH
Taranto
Alex Gutterres
AG
D037621:Artemisinins / Q000737:chemistry*; D003198:Computer Simulation; D004579:Electron Transport; D006418:Heme / Q000737:chemistry*; D006801:Humans; D008956:Models, Chemical; D008968:Molecular Conformation; D011789:Quantum Theory
D037621:Artemisinins; D006418:Heme; C031327:artemisinin