A-series agent A-234 belongs to a new generation of nerve agents. The poisoning of a former Russian spy Sergei Skripal and his daughter in Salisbury, England, in March 2018 led to the inclusion of A-234 and other A-series agents into the Chemical Weapons Convention. Even though five years have already passed, there is still very little information on its chemical properties, biological activities, and treatment options with established antidotes. In this article, we first assessed A-234 stability in neutral pH for subsequent experiments. Then, we determined its inhibitory potential towards human recombinant acetylcholinesterase (HssAChE; EC 3.1.1.7) and butyrylcholinesterase (HssBChE; EC 3.1.1.8), the ability of HI-6, obidoxime, pralidoxime, methoxime, and trimedoxime to reactivate inhibited cholinesterases (ChEs), its toxicity in rats and therapeutic effects of different antidotal approaches. Finally, we utilized molecular dynamics to explain our findings. The results of spontaneous A-234 hydrolysis showed a slow process with a reaction rate displaying a triphasic course during the first 72 h (the residual concentration 86.2%). A-234 was found to be a potent inhibitor of both human ChEs (HssAChE IC50 = 0.101 ± 0.003 μM and HssBChE IC50 = 0.036 ± 0.002 μM), whereas the five marketed oximes have negligible reactivation ability toward A-234-inhibited HssAChE and HssBChE. The acute toxicity of A-234 is comparable to that of VX and in the context of therapy, atropine and diazepam effectively mitigate A-234 lethality. Even though oxime administration may induce minor improvements, selected oximes (HI-6 and methoxime) do not reactivate ChEs in vivo. Molecular dynamics implies that all marketed oximes are weak nucleophiles, which may explain the failure to reactivate the A-234 phosphorus-serine oxygen bond characterized by low partial charge, in particular, HI-6 and trimedoxime oxime oxygen may not be able to effectively approach the A-234 phosphorus, while pralidoxime displayed low interaction energy. This study is the first to provide essential experimental preclinical data on the A-234 compound.
- MeSH
- acetylcholinesterasa MeSH
- antidota farmakologie MeSH
- butyrylcholinesterasa MeSH
- cholinesterasové inhibitory toxicita MeSH
- fosfor MeSH
- krysa rodu rattus MeSH
- kyslík MeSH
- lidé MeSH
- oximy farmakologie MeSH
- pralidoximové sloučeniny * MeSH
- pyridinové sloučeniny farmakologie MeSH
- reaktivátory cholinesterázy * farmakologie MeSH
- taurin analogy a deriváty MeSH
- trimedoxim farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Oxime reactivators are causal antidotes for organophosphate intoxication. Herein, the toxicity, pharmacokinetics, and reactivation effectiveness of o-chlorinated bispyridinium oxime K870 are reported. Oxime K870 was found to have a safe profile at a dose of 30 mg/kg in rats. It exhibited rapid absorption and renal clearance similar to those of other charged oximes after intramuscular administration. Its isoxazole-pyridinium degradation product was identified in vivo. Although it showed some improvement in brain targeting, it was nevertheless rapidly effluxed from the central nervous system. Its reactivation effectiveness was evaluated in rats and mice intoxicated with sarin, tabun, VX, and paraoxon and compared with pralidoxime and asoxime. K870 was found to be less effective in reversing tabun poisoning compared to its parent unchlorinated oxime K203. However, K870 efficiently reactivated blood acetylcholinesterase for all tested organophosphates in rats. In addition, K870 significantly protected against intoxication by all tested organophosphates in mice. For these reasons, oxime K870 seems to have a broader reactivation spectrum against multiple organophosphates. It seems important to properly modulate the oximate forming properties (pKa) to obtain more versatile oxime reactivators.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- antidota MeSH
- cholinesterasové inhibitory metabolismus toxicita MeSH
- krysa rodu rattus MeSH
- myši MeSH
- organofosfáty MeSH
- oximy * MeSH
- pyridinové sloučeniny toxicita MeSH
- reaktivátory cholinesterázy * terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
A series of tacrine - benzothiazole hybrids incorporate inhibitors of acetylcholinesterase (AChE), amyloid β (Aβ) aggregation and mitochondrial enzyme ABAD, whose interaction with Aβ leads to mitochondrial dysfunction, into a single molecule. In vitro, several of 25 final compounds exerted excellent anti-AChE properties and interesting capabilities to block Aβ aggregation. The best derivative of the series could be considered 10w that was found to be highly potent and selective towards AChE with the IC50 value in nanomolar range. Moreover, the same drug candidate exerted absolutely the best results of the series against ABAD, decreasing its activity by 23% at 100 μM concentration. Regarding the cytotoxicity profile of highlighted compound, it roughly matched that of its parent compound - 6-chlorotacrine. Finally, 10w was forwarded for in vivo scopolamine-induced amnesia experiment consisting of Morris Water Maze test, where it demonstrated mild procognitive effect. Taking into account all in vitro and in vivo data, highlighted derivative 10w could be considered as the lead structure worthy of further investigation.
- MeSH
- 3-hydroxyacyl-CoA-dehydrogenasy antagonisté a inhibitory metabolismus MeSH
- acetylcholinesterasa metabolismus MeSH
- Alzheimerova nemoc farmakoterapie metabolismus MeSH
- amyloidní beta-protein antagonisté a inhibitory metabolismus MeSH
- benzothiazoly chemie farmakologie MeSH
- cholinergní látky chemická syntéza chemie farmakologie MeSH
- inhibitory enzymů chemická syntéza chemie farmakologie MeSH
- lidé MeSH
- mitochondrie účinky léků metabolismus MeSH
- molekulární struktura MeSH
- neuroprotektivní látky chemická syntéza chemie farmakologie MeSH
- proteinové agregáty účinky léků MeSH
- takrin 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
- práce podpořená grantem MeSH
Autoři uvádějí případ mírné otravy organofosforovou sloučeninou. Taková otrava je v České republice poměrně raritní, a proto autoři na základě kazuistiky detailněji popisují typy organofosforových sloučenin, mechanizmy jejich účinku na organismus, příznaky otravy, možnosti diagnostiky a léčbu.
A case report of mild organophosphorus compound intoxication is presented in this paper. Such intoxication is very rare in the Czech Republic and therefore authors describe organophosphorus compounds, mechanisms of their action, diagnosis and treatment in more detail based on the case report.
A series of novel C4-C7-tethered biscoumarin derivatives (12a-e) linked through piperazine moiety was designed, synthesized, and evaluated biological/therapeutic potential. Biscoumarin 12d was found to be the most effective inhibitor of both acetylcholinesterase (AChE, IC50 = 6.30 μM) and butyrylcholinesterase (BChE, IC50 = 49 μM). Detailed molecular modelling studies compared the accommodation of ensaculin (well-established coumarin derivative tested in phase I of clinical trials) and 12d in the human recombinant AChE (hAChE) active site. The ability of novel compounds to cross the blood-brain barrier (BBB) was predicted with a positive outcome for compound 12e. The antiproliferative effects of newly synthesized biscoumarin derivatives were tested in vitro on human lung carcinoma cell line (A549) and normal colon fibroblast cell line (CCD-18Co). The effect of derivatives on cell proliferation was evaluated by MTT assay, quantification of cell numbers and viability, colony-forming assay, analysis of cell cycle distribution and mitotic activity. Intracellular localization of used derivatives in A549 cells was confirmed by confocal microscopy. Derivatives 12d and 12e showed significant antiproliferative activity in A549 cancer cells without a significant effect on normal CCD-18Co cells. The inhibition of hAChE/human recombinant BChE (hBChE), the antiproliferative activity on cancer cells, and the ability to cross the BBB suggest the high potential of biscoumarin derivatives. Beside the treatment of cancer, 12e might be applicable against disorders such as schizophrenia, and 12d could serve future development as therapeutic agents in the prevention and/or treatment of Alzheimer's disease.
- MeSH
- aktivace enzymů účinky léků MeSH
- Alzheimerova nemoc farmakoterapie MeSH
- antitumorózní látky chemická syntéza chemie farmakologie MeSH
- buněčný cyklus účinky léků MeSH
- buňky A549 MeSH
- cholinesterasové inhibitory chemická syntéza chemie farmakologie MeSH
- hematoencefalická bariéra účinky léků metabolismus MeSH
- kumariny chemická syntéza chemie farmakologie MeSH
- lidé MeSH
- molekulární modely * MeSH
- molekulární struktura MeSH
- techniky syntetické chemie * MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Aim: Organophosphorus compounds are irreversible inhibitors of AChE. Without immediate countermeasure, intoxication leads quickly to death. None of the clinically-used causal antidotes can ensure a good prognosis for any poisoned patient. When fallen into the wrong hands, organophosphates represent a serious threat to mankind. Results & methodology: Herein, we describe two novel compounds as unique merged molecules built on a tacrine scaffold against organophosphorus intoxication. These reactivators of AChE have balanced physicochemical properties, and should be able to cross the blood-brain barrier with a slightly lowered cytotoxicity profile compared to reference tacrine. Conclusion: Their efficiency compared with pralidoxime and obidoxime was proved against dichlorvos.
Nerve agents and oxon forms of organophosphorus pesticides act as strong irreversible inhibitors of two cholinesterases in the human body: acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BChE; EC 3.1.1.8), and are therefore highly toxic compounds. For the recovery of inhibited AChE, antidotes from the group of pyridinium or bispyridinium aldoxime reactivators (pralidoxime, obidoxime, HI-6) are used in combination with anticholinergics and anticonvulsives. Therapeutic efficacy of reactivators (called “oximes”) depends on their chemical structure and also the type of organophosphorus inhibitor. Three novel oximes (K131, K142, K153) with an oxime group in position four of the pyridinium ring were designed and then tested for their potency to reactivate human (Homo sapiens sapiens) AChE (HssACHE) and BChE (HssBChE) inhibited by the pesticide paraoxon (diethyl 4-nitrophenyl phosphate). According to the obtained results, none of the prepared oximes were able to satisfactorily reactivate paraoxon-inhibited cholinesterases. On the contrary, extraordinary activity of obidoxime in the case of paraoxon-inhibited HssAChE reactivation was confirmed. Additional docking studies pointed to possible explanations for these results.
- MeSH
- acetylcholinesterasa chemie MeSH
- antidota chemická syntéza farmakologie MeSH
- butyrylcholinesterasa chemie MeSH
- cholinesterasové inhibitory chemie MeSH
- enzymatické testy MeSH
- erytrocyty účinky léků enzymologie MeSH
- insekticidy antagonisté a inhibitory chemie toxicita MeSH
- interakční proteinové domény a motivy MeSH
- lidé MeSH
- obidoxim chlorid chemie farmakologie MeSH
- oximy chemická syntéza farmakologie MeSH
- paraoxon antagonisté a inhibitory chemie toxicita MeSH
- reaktivátory cholinesterázy chemická syntéza farmakologie MeSH
- sekundární struktura proteinů MeSH
- simulace molekulového dockingu MeSH
- termodynamika MeSH
- vazba proteinů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
