The risk of the use of toxic chemicals for unlawful acts has been a matter of concern for different governments and multilateral agencies. The Organisation for the Prohibition of Chemical Weapons (OPCW), which oversees the implementation of the Chemical Weapons Convention (CWC), considering recent events employing chemical warfare agents as means of assassination, has recently included in the CWC "Annex on Chemicals" some organophosphorus compounds that are regarded as acting in a similar fashion to the classical G- and V-series of nerve agents, inhibiting the pivotal enzyme acetylcholinesterase. Therefore, knowledge of the activity of the pyridinium oximes, the sole class of clinically available acetylcholinesterase reactivators to date, is plainly justified. In this paper, continuing our research efforts in medicinal chemistry on this class of toxic chemicals, we synthesized an A-230 nerve agent surrogate and applied a modified Ellman's assay to evaluate its ability to inhibit our enzymatic model, acetylcholinesterase from Electrophorus eel, and if the clinically available antidotes are able to rescue the enzyme activity for the purpose of relating the findings to the previously disclosed in silico data for the authentic nerve agent and other studies with similar A-series surrogates. Our experimental data indicates that pralidoxime is the most efficient compound for reactivating acetylcholinesterase inhibited by A-230 surrogate, which is the opposite of the in silico data previously disclosed.

• Klíčová slova
• A-230, Acetylcholinesterase, Antidotes, Chemical Weapons Convention, Nerve agent surrogates,
• MeSH
• acetylcholinesterasa * metabolismus   MeSH
• antidota farmakologie   MeSH
• chemické bojové látky * toxicita   MeSH
• cholinesterasové inhibitory * toxicita   MeSH
• nervová bojová látka * toxicita   MeSH
• organothiofosforové sloučeniny toxicita   MeSH
• oximy * farmakologie   MeSH
• pralidoximové sloučeniny farmakologie   MeSH
• pyridinové sloučeniny * farmakologie   MeSH
• reaktivátory cholinesterázy * farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa * MeSH
• antidota MeSH
• chemické bojové látky * MeSH
• cholinesterasové inhibitory * MeSH
• nervová bojová látka * MeSH
• organothiofosforové sloučeniny MeSH
• oximy * MeSH
• pralidoxime MeSH Prohlížeč
• pralidoximové sloučeniny MeSH
• pyridinové sloučeniny * MeSH
• reaktivátory cholinesterázy * MeSH

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 to be analogous to parent carboxamides (K027, K048 and K203). The inhibitory ability of thiocarboxamides was found in low µM levels for AChE and high µM levels for BChE. Their reactivation properties were screened on human recombinant AChE and BChE inhibited by nerve agent surrogates and paraoxon. One thiocarboxamide was able to effectively restore function of NEMP- and NEDPA-AChE, whereas two thiocarboxamides were able to reactivate BChE inhibited by all tested organophosphates. These results were confirmed by reactivation kinetics, where thiocarboxamides were proved to be effective, but less potent reactivators if compared to carboxamides.

• Klíčová slova
• Cholinesterase, inhibition, organophosphate, oxime, reactivation,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• butyrylcholinesterasa metabolismus   MeSH
• cholinesterasové inhibitory chemická syntéza   chemie   farmakologie   MeSH
• lidé MeSH
• molekulární struktura MeSH
• organofosfáty chemická syntéza   chemie   farmakologie   MeSH
• oximy chemická syntéza   chemie   farmakologie   MeSH
• pyridinové sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• sulfhydrylové sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• butyrylcholinesterasa MeSH
• cholinesterasové inhibitory MeSH
• organofosfáty MeSH
• oximy MeSH
• pyridinové sloučeniny MeSH
• sulfhydrylové sloučeniny MeSH

The pyridinium-2-carbaldoximes with quinolinium carboxamide moiety were designed and synthesised as cholinesterase reactivators. The prepared compounds showed intermediate-to-high inhibition of both cholinesterases when compared to standard oximes. Their reactivation ability was evaluated in vitro on human recombinant acetylcholinesterase (hrAChE) and human recombinant butyrylcholinesterase (hrBChE) inhibited by nerve agent surrogates (NIMP, NEMP, and NEDPA) or paraoxon. In the reactivation screening, one compound was able to reactivate hrAChE inhibited by all used organophosphates and two novel compounds were able to reactivate NIMP/NEMP-hrBChE. The reactivation kinetics revealed compound 11 that proved to be excellent reactivator of paraoxon-hrAChE better to obidoxime and showed increased reactivation of NIMP/NEMP-hrBChE, although worse to obidoxime. The molecular interactions of studied reactivators were further identified by in silico calculations. Molecular modelling results revealed the importance of creation of the pre-reactivation complex that could lead to better reactivation of both cholinesterases together with reducing particular interactions for lower intrinsic inhibition by the oxime.

• Klíčová slova
• Organophosphate, acetylcholinesterase, butyrylcholinesterase, oxime, reactivator,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• butyrylcholinesterasa metabolismus   MeSH
• chinolinové sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• cholinesterasové inhibitory chemická syntéza   chemie   farmakologie   MeSH
• lidé MeSH
• molekulární struktura MeSH
• pyridinové sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• rekombinantní proteiny metabolismus   MeSH
• simulace molekulového dockingu MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• butyrylcholinesterasa MeSH
• chinolinové sloučeniny MeSH
• cholinesterasové inhibitory MeSH
• pyridinové sloučeniny MeSH
• rekombinantní proteiny MeSH