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.

• Klíčová slova
• Acute toxicity, Hydrolysis, Nerve agent A-234, Reactivation, Therapy,
• 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 cholinesterasy * 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
• Názvy látek
• 2-(N-cyclohexylamino)ethanesulfonic acid MeSH Prohlížeč
• acetylcholinesterasa MeSH
• antidota MeSH
• asoxime chloride MeSH Prohlížeč
• butyrylcholinesterasa MeSH
• cholinesterasové inhibitory MeSH
• fosfor MeSH
• kyslík MeSH
• N,N'-monomethylenebis(pyridiniumaldoxime) MeSH Prohlížeč
• oximy MeSH
• pralidoxime MeSH Prohlížeč
• pralidoximové sloučeniny * MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy * MeSH
• taurin MeSH
• trimedoxim MeSH

Antidotes against organophosphates often possess physicochemical properties that mitigate their passage across the blood-brain barrier. Cucurbit[7]urils may be successfully used as a drug delivery system for bisquaternary oximes and improve central nervous system targeting. The main aim of these studies was to elucidate the relationship between cucurbit[7]uril, oxime K027, atropine, and paraoxon to define potential risks or advantages of this delivery system in a complex in vivo system. For this reason, in silico (molecular docking combined with umbrella sampling simulation) and in vivo (UHPLC-pharmacokinetics, toxicokinetics; acetylcholinesterase reactivation and functional observatory battery) methods were used. Based on our results, cucurbit[7]urils affect multiple factors in organophosphates poisoning and its therapy by (i) scavenging paraoxon and preventing free fraction of this toxin from entering the brain, (ii) enhancing the availability of atropine in the central nervous system and by (iii) increasing oxime passage into the brain. In conclusion, using cucurbit[7]urils with oximes might positively impact the overall treatment effectiveness and the benefits can outweigh the potential risks.

• Klíčová slova
• CB7, K027, acetylcholinesterase, antidote, cucurbit[7]uril, cucurbiturils, in vivo, mouse, paraoxon, pesticide,
• MeSH
• atropin chemie   MeSH
• hematoencefalická bariéra MeSH
• imidazoly chemie   MeSH
• myši MeSH
• oximy chemie   MeSH
• paraoxon chemie   toxicita   MeSH
• počítačová simulace MeSH
• přemostěné cyklické sloučeniny chemie   MeSH
• pyridinové sloučeniny chemie   MeSH
• reaktivátory cholinesterasy chemie   toxicita   MeSH
• simulace molekulového dockingu MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1-(4-hydroxyiminomethylpyridinium)-3-(carbamoylpyridinium) propane dibromide MeSH Prohlížeč
• atropin MeSH
• cucurbit(7)uril MeSH Prohlížeč
• imidazoly MeSH
• oximy MeSH
• paraoxon MeSH
• přemostěné cyklické sloučeniny MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy MeSH

"Novichoks" is the name given to the controversial chemical weapons supposedly developed in the former Soviet Union between the 1970s and the 1990s. Designed to be undetectable and untreatable, these chemicals became the most toxic of the nerve agents, being very attractive for both terrorist and chemical warfare purposes. However, very little information is available in the literature, and the Russian government did not acknowledge their development. The intent of this review is to provide the IJMS readers with a general overview on what is known about novichoks today. We briefly tell the story of the secret development of these agents, and discuss their synthesis, toxicity, physical-chemical properties, and possible ways of treatment and neutralization. In addition, we also wish to call the attention of the scientific community to the great risks still represented by nerve agents worldwide, and the need to keep constant investments in the development of antidotes and ways to protect against such deadly compounds.

• Klíčová slova
• Novichoks, binary weapon, chemical warfare, nerve agents,
• MeSH
• chemická válka * prevence a kontrola   MeSH
• chemické bojové látky chemická syntéza   chemie   toxicita   MeSH
• chemické jevy MeSH
• dekontaminace MeSH
• lidé MeSH
• nervová bojová látka chemická syntéza   chemie   toxicita   MeSH
• organofosfáty chemická syntéza   chemie   toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• chemické bojové látky MeSH
• nervová bojová látka MeSH
• novichok MeSH Prohlížeč
• organofosfáty MeSH

Chemical warfare agents constitute an increasing threat to both military and civilian populations. Therefore, effective prophylactic approaches are urgently needed. Herein, we present a novel hybrid compound which is able not only to keep acetylcholinesterase resistant to organophosphate (OP) inhibitors, but also to serve as an enzyme reactivator in the case of OP intoxication.

• Publikační typ
• časopisecké články MeSH