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

Poisoning with organophosphorus compounds used as pesticides or misused as chemical weapons remains a serious threat to human health and life. Their toxic effects result from irreversible blockade of the enzymes acetylcholinesterase and butyrylcholinesterase, which causes overstimulation of the cholinergic system and often leads to serious injury or death. Treatment of organophosphorus poisoning involves, among other strategies, the administration of oxime compounds. Oximes reactivate cholinesterases by breaking the covalent bond between the serine residue from the enzyme active site and the phosphorus atom of the organophosphorus compound. Although the general mechanism of reactivation has been known for years, the exact molecular aspects determining the efficiency and selectivity of individual oximes are still not clear. This hinders the development of new active compounds. In our research, using relatively simple and widely available molecular docking methods, we investigated the reactivation of acetyl- and butyrylcholinesterase blocked by sarin and tabun. For the selected oximes, their binding modes at each step of the reactivation process were identified. Amino acids essential for effective reactivation and those responsible for the selectivity of individual oximes against inhibited acetyl- and butyrylcholinesterase were identified. This research broadens the knowledge about cholinesterase reactivation and demonstrates the usefulness of molecular docking in the study of this process. The presented observations and methods can be used in the future to support the search for new effective reactivators.

• Klíčová slova
• acetylcholinesterase, butyrylcholinesterase, docking studies, molecular modeling, organophosphates, reactivation process, reactivators,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• aktivace enzymů MeSH
• butyrylcholinesterasa metabolismus   MeSH
• cholinesterasové inhibitory farmakologie   MeSH
• fosfor chemie   MeSH
• katalytická doména MeSH
• konformace proteinů MeSH
• kvantová teorie MeSH
• lidé MeSH
• ligandy MeSH
• molekulární modely MeSH
• myši MeSH
• organofosfáty chemie   MeSH
• oximy chemie   MeSH
• proteosyntéza MeSH
• reaktivátory cholinesterázy farmakologie   MeSH
• sarin chemie   MeSH
• shluková analýza MeSH
• simulace molekulového dockingu * MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• butyrylcholinesterasa MeSH
• cholinesterasové inhibitory MeSH
• fosfor MeSH
• ligandy MeSH
• organofosfáty MeSH
• oximy MeSH
• reaktivátory cholinesterázy MeSH
• sarin MeSH
• tabun MeSH Prohlížeč

Organophosphorus (OP) compounds are used as both chemical weapons and pesticides. However, these agents are very dangerous and toxic to humans, animals, and the environment. Thus, investigations with reactivators have been deeply developed in order to design new antidotes with better efficiency, as well as a greater spectrum of action in the acetylcholinesterase (AChE) reactivation process. With that in mind, in this work, we investigated the behavior of trimedoxime toward the Mus musculus acetylcholinesterase (MmAChE) inhibited by a range of nerve agents, such as chemical weapons. From experimental assays, reactivation percentages were obtained for the reactivation of different AChE-OP complexes. On the other hand, theoretical calculations were performed to assess the differences in interaction modes and the reactivity of trimedoxime within the AChE active site. Comparing theoretical and experimental data, it is possible to notice that the oxime, in most cases, showed better reactivation percentages at higher concentrations, with the best result for the reactivation of the AChE-VX adduct. From this work, it was revealed that the mechanistic process contributes most to the oxime efficiency than the interaction in the site. In this way, this study is important to better understand the reactivation process through trimedoxime, contributing to the proposal of novel antidotes.

• Klíčová slova
• acetylcholinesterase, computational methods, mechanistic studies, nerve agents, reactivation, trimedoxime,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• antidota farmakologie   MeSH
• cholinesterasové inhibitory metabolismus   farmakologie   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• nervová bojová látka chemie   MeSH
• organofosforové sloučeniny chemie   MeSH
• oximy chemie   MeSH
• reaktivátory cholinesterázy chemie   farmakologie   MeSH
• trimedoxim farmakologie   terapeutické užití   MeSH
• výpočetní biologie metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• antidota MeSH
• cholinesterasové inhibitory MeSH
• nervová bojová látka MeSH
• organofosforové sloučeniny MeSH
• oximy MeSH
• reaktivátory cholinesterázy MeSH
• trimedoxim MeSH

Acetylcholinesterase (AChE) is the key enzyme responsible for deactivating the ACh neurotransmitter. Irreversible or prolonged inhibition of AChE, therefore, elevates synaptic ACh leading to serious central and peripheral adverse effects which fall under the cholinergic syndrome spectra. To combat the toxic effects of some AChEI, such as organophosphorus (OP) nerve agents, many compounds with reactivator effects have been developed. Within the most outstanding reactivators, the substances denominated oximes stand out, showing good performance for reactivating AChE and restoring the normal synaptic acetylcholine (ACh) levels. This review was developed with the purpose of covering the new advances in AChE reactivation. Over the past years, researchers worldwide have made efforts to identify and develop novel active molecules. These researches have been moving farther into the search for novel agents that possess better effectiveness of reactivation and broad-spectrum reactivation against diverse OP agents. In addition, the discovery of ways to restore AChE in the aged form is also of great importance. This review will allow us to evaluate the major advances made in the discovery of new acetylcholinesterase reactivators by reviewing all patents published between 2016 and 2019. This is an important step in continuing this remarkable research so that new studies can begin.

• Klíčová slova
• acetylcholinesterase, new trends in reactivators, organophosphorus compounds, reactivation process, therapeutic potential,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• GPI-vázané proteiny metabolismus   MeSH
• lidé MeSH
• oximy chemie   terapeutické užití   MeSH
• patenty jako téma MeSH
• reaktivátory cholinesterázy * chemie   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• ACHE protein, human MeSH Prohlížeč
• GPI-vázané proteiny MeSH
• oximy MeSH
• reaktivátory cholinesterázy * MeSH

Therapeutic application of newly developed oximes is limited due to their adverse effects on different tissues. Within this article, it has been investigated which morphological changes could be observed in Wistar rats after the treatment with increasing doses of selected acetyl cholinesterase reactivators - asoxime, obidoxime, K027, K048, and K075. Subsequently, heart, diaphragm and musculus popliteus were obtained for pathohistological and semiquantitative analysis 24 hrs and 7 days after im administration of a single dose of 0.1 LD50, 0.5 LD50, and 1.0 LD50 of each oxime. Different muscle damage score was based on an estimation scale from 0 (no damage) to 5 (strong damage). In rats treated with 0.1 LD50 of each oxime, muscle fibres did not show any change. The intensive degeneration was found in all muscles after treatment with 0.5 LD50 of asoxime and obidoxime, respectively. Acute toxic muscle injury was developed within 7 days following treatment with 0.5 LD50 and 1.0 LD50 of each oxime, with the highest values in K048 and K075 group (P < 0.001 vs. control and asoxime), respectively. The early muscle alterations observed in our study seem to contribute to the pathogenesis of the oxime-induced toxic muscle injury, which probably manifests as necrosis and/or inflammation.

• MeSH
• bránice účinky léků   zranění   MeSH
• kosterní svaly účinky léků   zranění   MeSH
• krysa rodu Rattus MeSH
• myozitida chemicky indukované   MeSH
• nekróza MeSH
• oximy toxicita   MeSH
• potkani Wistar MeSH
• pyridinové sloučeniny toxicita   MeSH
• srdce účinky léků   MeSH
• svaly účinky léků   patologie   MeSH
• testy akutní toxicity MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-(4-hydroxyiminomethylpyridinium)-3-(carbamoylpyridinium) propane dibromide MeSH Prohlížeč
• 1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)butane MeSH Prohlížeč
• K075 compound MeSH Prohlížeč
• oximy MeSH
• pyridinové sloučeniny MeSH