Different behavior of artemisinin and tetraoxane in the oxidative degradation of phospholipid
作者:Naokazu Kumura、Hirotaka Furukawa、Arnold N. Onyango、Minoru Izumi、Shuhei Nakajima、Hideyuki Ito、Tsutomu Hatano、Hye-Sook Kim、Yusuke Wataya、Naomichi Baba
DOI:10.1016/j.chemphyslip.2009.04.005
日期:2009.8
The reaction of trioxane and tetraoxane endoperoxides with unsaturated phospholipid I in the presence of Fe(II) was investigated in the absence of oxygen by means of tandem ESI-MS analysis. The spectral analyses for the reaction mixtures showed that artemisinin 2 with a trioxane structure gave no peak except that for the remaining intact phospholipid 1 (m/z 758.9), indicating that there was no structural change to 1. On other hand, the reaction mixture of I with tetraoxanes 3 and 4 afforded a number of new peaks (m/z 620-850) that were presumably assigned to oxidative degradation products originating from phospholipid 1. Since this reaction was completely inhibited by the addition of a phenolic antioxidant. the process was considered to involve some free radical species. The newly discovered marked differences in reactivity between the trioxane and the tetraoxanes possibly reflects their different anti-malarial mechanisms, and this reactivity may contribute to the classification of a number of anti-malarial endoperoxides whose mode of action is based on phospholipid oxidation. (C) 2009 Elsevier Ireland Ltd. All rights reserved.