Background: Oxime K033 was considered a promising drug candidate originally developed
for the treatment of nerve agent poisoning. This study summarizes its potency to reactivate in
vitro acetylcholinesterase inhibited by several nerve agents (tabun, sarin, cyclosarin, soman, VX,
Russian VX), mimic agent (DFP) and organophosphorus pesticide (chlorpyrifos) to show whether
this compound might be used in cases of nerve agent or pesticide poisoning and considered as a
so-called “broad spectrum reactivator”.
Methods: Moreover, docking studies of tested oxime with human AChE (HssAChE) complexed
with several OPs were performed in order to verify its stability, binding modes and ability to adopt
favourable conformations and to perform the reactivation reaction with each OP under experimental
Results & Conclusion: According to the obtained results, K033 could not be considered a universal
antidote due to its poor reactivation activity in the case of tabun-, soman- and DFP-inhibited rat
acetylcholinesterase. On the contrary, its very good in vitro potency in human-relevant doses for
cyclosarin inhibition is highlighted.