Abstract：
Acetylcholinesterase (AChE) inhibition by organophosphorus (OP) compounds poses a serious health risk to humans. While many therapeutics have been tested for treatment after OP exposure, there is still a need for efficient reactivation against all kinds of OP compounds, and current oxime therapeutics have poor blood-brain barrier penetration into the central nervous system, while offering no recovery in activity from the OP-aged forms of AChE. Herein, we report a novel library of 4-amidophenol quinone methide precursors (QMP) that provide effective reactivation against multiple OP-inhibited forms of AChE in addition to resurrecting the aged form of AChE after exposure to a pesticide or some phosphoramidates. Furthermore, these QMP compounds also reactivate OP-inhibited butyrylcholinesterase (BChE) which is an in vivo, endogenous scavenger of OP compounds. The in vitro efficacies of these QMP compounds were tested for reactivation and resurrection of soluble forms of human AChE and BChE and for reactivation of cholinesterases within human blood as well as blood and brain samples from a humanized mouse model. We identify compound 10c as a lead candidate due to its broad-scope efficacy against multiple OP compounds as well as both cholinesterases. With methylphosphonates, compound 10c (250 μM, 1 h) shows >60% recovered activity from OEt-inhibited AChE in human blood as well as mouse blood and brain, thus highlighting its potential for future in vivo analysis. For 10c, the effective concentration (EC50) is less than 25 μM for reactivation of three different methylphosphonate-inhibited forms of AChE, with a maximum reactivation yield above 80%. Similarly, for OP-inhibited BChE, 10c has EC50 values that are less than 150 μM for two different methylphosphonate compounds. Furthermore, an in vitro kinetic analysis show that 10c has a 2.2- and 92.1-fold superior reactivation efficiency against OEt-inhibited and OiBu-inhibited AChE, respectively, when compared to an oxime control. In addition to 10c being a potent reactivator of AChE and BChE, we also show that 10c is capable of resurrecting (ethyl paraoxon)-aged AChE, which is another current limitation of oximes.
摘要：
有机磷（OP）化合物对乙酰胆碱酯酶（AChE）的抑制作用对人类构成了严重的健康风险。虽然许多疗法已经在OP暴露后进行了治疗测试，仍然需要对各种OP化合物进行有效的再活化，目前的肟疗法对中枢神经系统的血脑屏障渗透较差，同时不提供从OP年龄形式的AChE中恢复的活动。在这里，我们报道了一个新的4-氨基苯酚醌甲基化物前体(QMP)文库,该文库除了在暴露于杀虫剂或一些氨基磷酸酯后恢复老化形式的AChE外,还提供了对多种OP抑制形式的AChE的有效再活化.此外，这些QMP化合物还重新激活OP抑制的丁酰胆碱酯酶（BChE），OP化合物的内源性清除剂。针对人AChE和BChE的可溶形式的再活化和复活以及针对人血液以及来自人源化小鼠模型的血液和脑样品中的胆碱酯酶的再活化,测试了这些QMP化合物的体外效力。由于化合物10c对多种OP化合物以及两种胆碱酯酶具有广泛的功效，因此我们将其鉴定为先导候选物。甲基膦酸酯，化合物10c(250μM，1h）显示>60％的恢复活性从OEt抑制AChE在人血液以及小鼠血液和大脑，从而突出了其未来体内分析的潜力。对于10c，有效浓度（EC50）小于25μM，用于激活三种不同的甲基膦酸酯抑制形式的AChE，最大再活化产率高于80%。同样，对于OP抑制的BChE，图10c对于两种不同的甲基膦酸酯化合物具有小于150μM的EC50值。此外，体外动力学分析表明，10c对OEt抑制和OiBu抑制的AChE具有2.2倍和92.1倍的优异再活化效率，分别,与肟对照相比。除了10c是AChE和BChE的强效激活剂外，我们还表明10c能够复活（乙基对氧磷）老化的AChE，这是目前肟的另一个限制。
