Facile Oxidation of Leucomethylene Blue and Dihydroflavins by Artemisinins: Relationship with Flavoenzyme Function and Antimalarial Mechanism of Action
作者:Richard K. Haynes、Wing-Chi Chan、Ho-Ning Wong、Ka-Yan Li、Wai-Keung Wu、Kit-Man Fan、Herman H. Y. Sung、Ian D. Williams、Davide Prosperi、Sergio Melato、Paolo Coghi、Diego Monti
DOI:10.1002/cmdc.201000225
日期:——
oxygen with generation of ROS. Reduction of the artemisinin is proposed to occur via hydride transfer from LMB or the dihydroflavin to O1 of the peroxide. This hitherto unrecorded reactivity profile conforms with known structure–activity relationships of artemisinins, is consistent with their known ability to generate ROS in vivo, and explains the synergism between artemisinins and redox‐active antimalarial
抗疟药亚甲蓝(MB)影响寄生虫黄素依赖性二硫键还原酶(如谷胱甘肽还原酶(GR))的氧化还原行为,该酶控制疟疾寄生虫中的氧化应激。还原的黄素腺嘌呤二核苷酸辅因子FADH 2引发还原为亚乙蓝(LMB),其被氧气氧化以生成活性氧(ROS)和MB。然后,MB充当NADPH的颠覆性底物,而NADPH通常是再生FADH 2所需的酶功能。MB与过氧化抗疟疾青蒿素衍生物青蒿琥酯之间的协同作用表明青蒿素具有互补的作用方式。我们发现青蒿素被MB和抗坏血酸(AA)或N生成的LMB转化苄基二氢神经酰胺(BNAH)在生理pH条件下在水性缓冲液中原位转化为单电子转移(SET)重排产物或双电子还原产物,后者以BNAH为主。AA和BNAH均不影响青蒿素。在有氧条件下,AA–MB SET反应会增强,并且此处获得的主要产物在结构上与一种据报道已在细胞内培养基中形成的此类产物密切相关。调用通过SET与青蒿素产生的酮基来解释