Oxime K203: a drug candidate for the treatment of tabun intoxication
摘要:
For over 60 years, researchers across the world have sought to deal with poisoning by nerve agents, the most toxic and lethal chemical weapons. To date, there is no efficient causal antidote with sufficient effect. Every trialed compound fails to fulfil one or more criteria (e.g. reactivation potency, broad reactivation profile). In this recent contribution, we focused our attention to one of the promising compounds, namely the bis-pyridinium reactivator K203. The oxime K203 is very often cited as the best reactivator against tabun poisoning. Herein, we provide all the available literature data in comprehensive and critical review to address whether K203 could be considered as a new drug candidate against organophosphorus poisoning with the stress on tabun. We describe its development from the historical point of view and review all available in vitro as well as in vivo data to date. K203 is easily accessible by a relatively simple two-step synthesis. It is well accommodated in the enzyme active gorge of acetylcholinesterase providing suitable interactions for reactivation, as shown by molecular docking simulations. According to a literature survey, in vitro data for tabun-inhibited AChE are extraordinary. However, in vivo efficiency remains unconvincing. The K203 toxicity profile did not show any perturbations compared to clinically used standards; on the other hand versatility of K203 does not exceed currently available oximes. In summary, K203 does not seem to address current issues associated with the organophosphorus poisoning, especially the broad profile against all nerve agents. However, its reviewed efficacy entitles K203 to be considered as a backup or tentative replacement for obidoxime and trimedoxime, currently only available anti-tabun drugs.
Fluorinated pyridinium oximes as potential reactivators for acetylcholinesterases inhibited by paraoxon organophosphorus agent
作者:Hee Chun Jeong、No-Joong Park、Chong Hak Chae、Kamil Musilek、Jiri Kassa、Kamil Kuca、Young-Sik Jung
DOI:10.1016/j.bmc.2009.07.043
日期:2009.9
fluorinated oxime compounds was designed and synthesized in order to probe the effect of fluorine substitution on reactivation of inhibited acetylcholinesterase (AChE) by organophosphorus agents. Permeability measurements, using the Parallel Artificial Membrane Permeation Assays (PAMPA) method, were employed to experimentally demonstrate that membrane permeabilities of the series of oximes increase in
The newly developed and very promising acetylcholinesterase reactivator (E)-1- (2-hydroxyiminomethylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E)-1-(4-bromobut-2-enyl)-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested.
Charged pyridinium oximes with thiocarboxamide moiety are equally or less effective reactivators of organophosphate-inhibited cholinesterases compared to analogous carboxamides
Abstract The organophosphorus antidotes, so-called oximes, are able to restore the enzymatic function of acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) via cleavage of organophosphate from the active site of the phosphylated enzyme. In this work, the charged pyridinium oximes containing thiocarboxamide moiety were designed, prepared and tested. Their stability and pKa properties were found
Design of a Potent Reactivator of Tabun-Inhibited AcetylcholinesteraseSynthesis and Evaluation of (<i>E</i>)-1-(4-Carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene Dibromide (K203)
Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Among the organophosphates, with the exception of soman, tabun (GA) intoxications are the least responsive to treatment with commercially available therapeutics. A rational design was used to increase reactivation ability and decrease the toxicity of the novel reactivator. (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203) has better properties than previously tested compounds in vitro and, therefore, is a potential candidate for the treatment of GA intoxication in vivo.
Synthesis of the novel series of bispyridinium compounds bearing (E)-but-2-ene linker and evaluation of their reactivation activity against chlorpyrifos-inhibited acetylcholinesterase
Six potential AChE reactivators were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by insecticide chlorpyrifos was tested in vitro. According to the results, (E)-1-(2-hydroxyiminomethylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide seems to be the most potent AChE reactivator. The reactivation potency of these compounds depends on structural factors such as constitution of the linking chain between both pyridinium rings, position of the oxime moiety at the pyridinium ring and presence of quaternary nitrogens. (c) 2005 Elsevier Ltd. All rights reserved.