Theoretical Study Of The Interaction Between Artemisinin And Heme [estudo Teórico Da Interação Existente Entre A Artemisinina E O Heme]

摘要

The purpose of this work is to study theoretically stereoelectronic aspects of the interaction between heme and artemisinin in the transitional heme-artemisinin complex. Through semi-empirical calculations using the PM3 method, the potential energy barrier of artemisinin rotation relative to heme in the heme-artemisinin complex was studied in vacuum and in the partially solvated state. The minimum heat of formation obtained for the complex with and without water molecules is -702.39 and -100.86 kcal mol -1, respectively, which corresponds to the dihedral angle CFe-O1-O2 of 43.93° and 51.90° around the iron-oxygen O1 bond, respectively. The water molecules bind to heme via 13 hydrogen bonds and O-H⋯O and 6 C-H⋯O interactions, which accounts for -67.23 kcal mol -1. It is observed that the inclusion of water molecules does not affect significantly the stability of the heme-artemisinin complex.