1
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Voros C, Dias J, Timperley CM, Nachon F, Brown RCD, Baati R. The risk associated with organophosphorus nerve agents: from their discovery to their unavoidable threat, current medical countermeasures and perspectives. Chem Biol Interact 2024; 395:110973. [PMID: 38574837 DOI: 10.1016/j.cbi.2024.110973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/13/2024] [Accepted: 03/21/2024] [Indexed: 04/06/2024]
Abstract
The first organophosphorus nerve agent was discovered accidently during the development of pesticides, shortly after the first use of chemical weapons (chlorine, phosgene) on the battlefield during World War I. Despite the Chemical Weapons Convention banning these substances, they have still been employed in wars, terrorist attacks or political assassinations. Characterised by their high lethality, they target the nervous system by inhibiting the acetylcholinesterase (AChE) enzyme, preventing neurotransmission, which, if not treated rapidly, inevitably leads to serious injury or the death of the person intoxicated. The limited efficacy of current antidotes, known as AChE reactivators, pushes research towards new treatments. Numerous paths have been explored, from modifying the original pyridinium oximes to developing hybrid reactivators seeking a better affinity for the inhibited AChE. Another crucial approach resides in molecules more prone to cross the blood-brain barrier: uncharged compounds, bio-conjugated reactivators or innovative formulations. Our aim is to raise awareness on the threat and toxicity of organophosphorus nerve agents and to present the main synthetic efforts deployed since the first AChE reactivator, to tackle the task of efficiently treating victims of these chemical warfare agents.
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Affiliation(s)
- Camille Voros
- Ecole de Chimie Polymère et Matériaux ECPM, Université de Strasbourg, ICPEES UMR CNRS 7515, 25 rue Becquerel, F-67087, Strasbourg, France.
| | - José Dias
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, F-91220 Brétigny-sur-Orge, France
| | - Christopher M Timperley
- Chemical, Biological and Radiological (CBR) Division, Dstl, Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK.
| | - Florian Nachon
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, F-91220 Brétigny-sur-Orge, France
| | - Richard C D Brown
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - Rachid Baati
- Ecole de Chimie Polymère et Matériaux ECPM, Université de Strasbourg, ICPEES UMR CNRS 7515, 25 rue Becquerel, F-67087, Strasbourg, France; OPGS Pharmaceuticals, Paris BioTech Santé, 24 rue du Faubourg Saint-Jacques, F-75014, Paris, France.
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2
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Lindgren C, Forsgren N, Hoster N, Akfur C, Artursson E, Edvinsson L, Svensson R, Worek F, Ekström F, Linusson A. Broad‐Spectrum Antidote Discovery by Untangling the Reactivation Mechanism of Nerve‐Agent‐Inhibited Acetylcholinesterase. Chemistry 2022; 28:e202200678. [PMID: 35420233 PMCID: PMC9400889 DOI: 10.1002/chem.202200678] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Indexed: 11/13/2022]
Abstract
Reactivators are vital for the treatment of organophosphorus nerve agent (OPNA) intoxication but new alternatives are needed due to their limited clinical applicability. The toxicity of OPNAs stems from covalent inhibition of the essential enzyme acetylcholinesterase (AChE), which reactivators relieve via a chemical reaction with the inactivated enzyme. Here, we present new strategies and tools for developing reactivators. We discover suitable inhibitor scaffolds by using an activity‐independent competition assay to study non‐covalent interactions with OPNA‐AChEs and transform these inhibitors into broad‐spectrum reactivators. Moreover, we identify determinants of reactivation efficiency by analysing reactivation and pre‐reactivation kinetics together with structural data. Our results show that new OPNA reactivators can be discovered rationally by exploiting detailed knowledge of the reactivation mechanism of OPNA‐inhibited AChE.
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Affiliation(s)
| | - Nina Forsgren
- CBRN Defense and Security Swedish Defense Research Agency 906 21 Umeå Sweden
| | - Norman Hoster
- Department of Chemistry Umeå University 901 87 Umeå Sweden
| | - Christine Akfur
- CBRN Defense and Security Swedish Defense Research Agency 906 21 Umeå Sweden
| | - Elisabet Artursson
- CBRN Defense and Security Swedish Defense Research Agency 906 21 Umeå Sweden
| | | | - Richard Svensson
- Biomedicinskt Centrum BMC Uppsala University 752 37 Uppsala Sweden
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology 80937 Munich Germany
| | - Fredrik Ekström
- CBRN Defense and Security Swedish Defense Research Agency 906 21 Umeå Sweden
| | - Anna Linusson
- Department of Chemistry Umeå University 901 87 Umeå Sweden
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3
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Novel Group of AChE Reactivators-Synthesis, In Vitro Reactivation and Molecular Docking Study. Molecules 2018; 23:molecules23092291. [PMID: 30205495 PMCID: PMC6225275 DOI: 10.3390/molecules23092291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/03/2018] [Accepted: 09/05/2018] [Indexed: 11/24/2022] Open
Abstract
The acetylcholinesterase (AChE) reactivators (e.g., obidoxime, asoxime) became an essential part of organophosphorus (OP) poisoning treatment, together with atropine and diazepam. They are referred to as a causal treatment of OP poisoning, because they are able to split the OP moiety from AChE active site and thus renew its function. In this approach, fifteen novel AChE reactivators were determined. Their molecular design originated from former K-oxime compounds K048 and K074 with remaining oxime part of the molecule and modified part with heteroarenium moiety. The novel compounds were prepared, evaluated in vitro on human AChE (HssAChE) inhibited by tabun, paraoxon, methylparaoxon or DFP and compared to commercial HssAChE reactivators (pralidoxime, methoxime, trimedoxime, obidoxime, asoxime) or previously prepared compounds (K048, K074, K075, K203). Some of presented oxime reactivators showed promising ability to reactivate HssAChE comparable or higher than the used standards. The molecular modelling study was performed with one compound that presented the ability to reactivate GA-inhibited HssAChE. The SAR features concerning the heteroarenium part of the reactivator’s molecule are described.
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Pooja P, Aggarwal S, Tiwari AK, Kumar V, Pratap R, Singh G, Mishra AK. Novel pyridinium oximes: synthesis, molecular docking and in vitro reactivation studies. RSC Adv 2015. [DOI: 10.1039/c4ra14696d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A computational approach has been attempted for the screening of 4-pyridoxinium (4P) ring based reactivators for paraoxon inhibited AChE.
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Affiliation(s)
- Pooja Pooja
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Delhi-110054
- India
- Department of Chemistry
| | - S. Aggarwal
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Delhi-110054
- India
- Department of Chemistry
| | - A. K. Tiwari
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Delhi-110054
- India
| | - V. Kumar
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Delhi-110054
- India
| | - R. Pratap
- Department of Chemistry
- University of Delhi
- Delhi-110054
- India
| | - G. Singh
- Department of Chemistry
- University of Delhi
- Delhi-110054
- India
| | - A. K. Mishra
- Division of Cyclotron and Radiopharmaceutical Sciences
- Institute of Nuclear Medicine and Allied Sciences
- Delhi-110054
- India
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5
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Gupta B, Sharma R, Singh N, Kuca K, Acharya JR, Ghosh KK. In vitro reactivation kinetics of paraoxon- and DFP-inhibited electric eel AChE using mono- and bis-pyridinium oximes. Arch Toxicol 2013; 88:381-90. [PMID: 24065055 DOI: 10.1007/s00204-013-1136-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 09/12/2013] [Indexed: 11/25/2022]
Abstract
Oxime-assisted reactivation of organophosphate (OP)-inhibited acetylcholinesterase (AChE) is a crucial step in the post-inhibitory treatment of OP intoxication. The limited efficacy of oxime reactivators for all OP nerve agents and pesticides led to the development of various novel oximes and their thorough kinetic investigations. Hence, in the present investigation, we have tested 10 structurally different pyridinium oxime-based reactivators for their in vitro potency to reactivate paraoxon- and DFP-inhibited electric eel AChE. From structure activity relationship point of view, various oximes such as mono-quaternary (2-PAM, K100, K024) and bis-quaternary symmetric (obidoxime, TMB-4) and asymmetric (K027, K048, K203, K618, K628) oximes bearing different connecting linkers (oxybismethylene, trimethylene, propane, butane, butene, and xylene) have been studied. The observed kinetic data demonstrate that not only the position of oxime group is decisive for the increased reactivation ability of oximes, but the role of connecting linker is also significant. Oximes with aliphatic linkers are superior reactivators than the oximes with unsaturated and aromatic linkers. The optimal chain length for plausible reactivation ability for paraoxon- and DFP-inhibited AChE is 3 or 4 carbon-carbon connecting linker between prydinium rings.
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Affiliation(s)
- Bhanushree Gupta
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, 492010, CG, India
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Sepsova V, Karasova JZ, Korabecny J, Dolezal R, Zemek F, Bennion BJ, Kuca K. Oximes: inhibitors of human recombinant acetylcholinesterase. A structure-activity relationship (SAR) study. Int J Mol Sci 2013; 14:16882-900. [PMID: 23959117 PMCID: PMC3759941 DOI: 10.3390/ijms140816882] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/01/2013] [Accepted: 08/02/2013] [Indexed: 11/16/2022] Open
Abstract
Acetylcholinesterase (AChE) reactivators were developed for the treatment of organophosphate intoxication. Standard care involves the use of anticonvulsants (e.g., diazepam), parasympatolytics (e.g., atropine) and oximes that restore AChE activity. However, oximes also bind to the active site of AChE, simultaneously acting as reversible inhibitors. The goal of the present study is to determine how oxime structure influences the inhibition of human recombinant AChE (hrAChE). Therefore, 24 structurally different oximes were tested and the results compared to the previous eel AChE (EeAChE) experiments. Structural factors that were tested included the number of pyridinium rings, the length and structural features of the linker, and the number and position of the oxime group on the pyridinium ring.
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Affiliation(s)
- Vendula Sepsova
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; E-Mails: (V.S.); (J.K.); (F.Z.)
| | - Jana Zdarova Karasova
- Department of Public Health, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; E-Mail:
- University Hospital, Biomedicinal Research Centre, Sokolska 581, 50005 Hradec Kralove, Czech Republic; E-Mail:
| | - Jan Korabecny
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; E-Mails: (V.S.); (J.K.); (F.Z.)
- University Hospital, Biomedicinal Research Centre, Sokolska 581, 50005 Hradec Kralove, Czech Republic; E-Mail:
| | - Rafael Dolezal
- University Hospital, Biomedicinal Research Centre, Sokolska 581, 50005 Hradec Kralove, Czech Republic; E-Mail:
| | - Filip Zemek
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; E-Mails: (V.S.); (J.K.); (F.Z.)
| | - Brian J. Bennion
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA; E-Mail:
| | - Kamil Kuca
- University Hospital, Biomedicinal Research Centre, Sokolska 581, 50005 Hradec Kralove, Czech Republic; E-Mail:
- Center of Advances Studies, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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7
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Petroianu GA, Hasan MY, Nurulain SM, Nagelkerke N, Kassa J, Kuca K. New K-Oximes (K-27 and K-48) in Comparison with Obidoxime (LuH-6), HI-6, Trimedoxime (TMB-4), and Pralidoxime (2-PAM): Survival in Rats Exposed IP to the Organophosphate Paraoxon. Toxicol Mech Methods 2012; 17:401-8. [PMID: 20020943 DOI: 10.1080/15376510601131362] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
ABSTRACT Oximes are cholinesterase reactivators used in organophosphorus compound poisoning. The purpose of the study was to compare the protective effect of the K-oximes (K-27 and K-48) in male rats with that of obidoxime (LuH-6), trimedoxime (TMB-4), and HI-6, using paraoxon (POX) as a cholinesterase inhibitor. Pralidoxime (2-PAM) was also retested. Seven groups of six rats each were used. Group 1 (G(1)) received 1 mumol/rat POX ( approximately LD(75)), the other groups (G(2-7)) received 1 mumol/rat POX + one of the six reactivators. The animals were monitored for 48 h and time of mortality was recorded. The procedure was repeated seven times. Subsequently, experiments as described were repeated using 10 and 15 mumol/rat POX. Mortality data were compared and hazards ratios (relative risks) ranked with the Cox proportional hazards model using the POX dose and group (reactivator) as time-independent covariables. K-27 followed by K-48 were the most potent reactivators. K-27 was statistically significantly superior to all other reactivators except K-48. The relative risk of death estimated by Cox analysis in K-27- and K-48-treated animals when compared with untreated animals, adjusted for the POX dose, was 0.22 (95% confidence interval [CI], 0.15 to 0.31) and 0.26 (95% CI, 0.18 to 0.37), respectively. We concluded that in the animal model used K-27 and K-48 are superior to older oximes in their ability to protect from paraoxon effects. They should be tested further using methyl- and propyl-organophosphates as toxic agents.
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Affiliation(s)
- G A Petroianu
- United Arab Emirates University, Al Ain-United Arab Emirates
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8
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The present approaches to the development of prophylactic and therapeutic antidotes against nerve agents. Interdiscip Toxicol 2011; 1:18-21. [PMID: 21218100 PMCID: PMC2993476 DOI: 10.2478/v10102-010-0026-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 05/09/2008] [Accepted: 05/12/2008] [Indexed: 11/21/2022] Open
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9
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Musilek K, Komloova M, Holas O, Horova A, Pohanka M, Gunn-Moore F, Dohnal V, Dolezal M, Kuca K. Mono-oxime bisquaternary acetylcholinesterase reactivators with prop-1,3-diyl linkage—Preparation, in vitro screening and molecular docking. Bioorg Med Chem 2011; 19:754-62. [DOI: 10.1016/j.bmc.2010.12.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 12/05/2010] [Accepted: 12/07/2010] [Indexed: 11/30/2022]
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10
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Kuca K, Cabal J, Jun D, Musilek K, Soukup O, Pohanka M, Pejchal J, Oh KA, Yang GY, Jung YS. Reactivation of VX-inhibited AChE by novel oximes having two oxygen atoms in the linker. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2010; 30:85-87. [PMID: 21787634 DOI: 10.1016/j.etap.2010.03.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Revised: 03/09/2010] [Accepted: 03/10/2010] [Indexed: 05/31/2023]
Abstract
Two newly developed AChE reactivators possessing two oxime groups in 4-position of the pyridinium rings with linkers CH(2)O(CH(2))(2)OCH(2) and CH(2)O(CH(2))(4)OCH(2) were tested for their potency to reactivate VX-inhibited AChE. Their reactivation potency was compared with currently available oximes such as pralidoxime, obidoxime and HI-6. Appropriate constants (affinity towards the intact and inhibited enzyme, reactivation rate) characterizing the reactivation process were determined. According to the data obtained, a new oxime with CH(2)O(CH(2))(2)OCH(2) linker reached as high reactivation potency as HI-6. The percentage of reactivation of the oxime with CH(2)O(CH(2))(2)OCH(2) linker was comparable to that of obidoxime at a concentration 10(-3)M. Hence, these oximes may be worthy of future development for the treatment of nerve agent intoxications, especially, with lipophilic agents such as soman and cyclosarin.
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Affiliation(s)
- Kamil Kuca
- Center of Advanced Studies, Hradec Kralove, Czech Republic; Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
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11
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Holas O, Musilek K, Pohanka M, Kuca K, Opletalova V, Jung YS. In vitro Screening of Oxime Reactivators on the Model of Paraoxon-inhibited Acetylcholinesterase-SAR Study. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.6.1609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Musilek K, Dolezal M, Gunn-Moore F, Kuca K. Design, evaluation and structure-activity relationship studies of the AChE reactivators against organophosphorus pesticides. Med Res Rev 2009; 31:548-75. [PMID: 20027669 DOI: 10.1002/med.20192] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Organophosphate pesticides (OPPs; e.g. chlorpyrifos, diazinon, paraoxon) are a wide and heterogeneous group of organophosphorus compounds. Their biological activity of inhibiting acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) ranks them as life endangering agents. The necessary treatment after OPP exposure involves the use of parasympatolytics (e.g. atropine), oxime reactivators (e.g. obidoxime), and anticonvulsive drugs (e.g. diazepam). Therefore, the reactivators of AChE are essential compounds in the treatment of OPP intoxications. Commercial AChE reactivators (e.g. pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) were originally developed for other members of the organophosphate family, such as nerve agents (e.g. sarin, soman, tabun, VX). Pralidoxime, HI-6, and methoxime were found to be weak reactivators of OPP-inhibited AChE. Obidoxime and trimedoxime showed satisfactory reactivation against various OPPs with minor toxicity issues. During the last two decades, the treatment of OPP exposure has become more widely discussed because of growing agricultural production, industrialization, and harmful social issues (e.g. suicides). In this review is the summarized design, evaluation, and structure-activity relationship studies of recently produced AChE reactivators. Since pralidoxime, over 300 oximes have been produced or tested against OPP poisoning, and several novel compounds show very promising abilities as comparable (or higher) to commercial oximes. Some of these are highlighted for their further testing of OPP exposure and, additionally, the main structure-activity relationship of AChE reactivators against OPP is discussed.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Trebesska, Hradec Kralove, Czech Republic.
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13
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Lorke DE, Hasan MY, Nurulain SM, Kuca K, Schmitt A, Petroianu GA. Efficacy of two new asymmetric bispyridinium oximes (K-27 and K-48) in rats exposed to diisopropylfluorophosphate: comparison with pralidoxime, obidoxime, trimedoxime, methoxime, and HI-6. Toxicol Mech Methods 2009; 19:327-33. [PMID: 19778224 DOI: 10.1080/15376510902798695] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Introduction. The new K-oximes, K-27 [1-(4-hydroxyimino-methylpyridinium)-4-(4-carbamoylpyridinium) propane dibromide] and K-48 [1-(4-hydroxyimino-methylpyridinium)-4-(4-carbamoylpyridinium) butane dibromide], show good in vitro efficacy in protecting acetylcholinesterase from inhibition by different organophosphorus compounds (OPCs), including nerve agents. To assess their efficacy in vivo, the extent of oxime-conferred protection from mortality induced by diisopropylfluorophosphate (DFP) was quantified and compared with that of five established oximes. Materials and Methods. Rats received DFP intraperitoneally in a dosage of 6, 8, or 10 micromol/rat and immediately thereafter intraperitoneal injections of K-27, K-48, pralidoxime, obidoxime, trimedoxime, methoxime, or HI-6. The relative risk (RR) of death over time (48 h) was estimated by Cox survival analysis, comparing results with the no-treatment group. Results. Best protection was observed when K-27 was used, reducing the RR of death to 19% of control RR (p < or = 0.005), whereas obidoxime (RR = 26%, p < or = 0.01), K-48 (RR = 29%, p < or = 0.005) and methoxime (RR = 26%, p < or = 0.005) were comparable. The RR of death was reduced only to about 35% of control by HI-6, to 45% by trimedoxime, and to 59% by 2-PAM (p < or = 0.005). Whereas the differences between the best oximes (K-27, obidoxime, methoxime, and K-48) were not statistically significant; these four oximes were significantly more effective than 2-PAM (p < or = 0.05). The efficacy of K-27 was also significantly higher than that of HI-6, trimedoxime, and 2-PAM (p < or = 0.05). Conclusion. Our data provide further evidence that K-27 is a very promising candidate for the treatment of intoxication with a broad spectrum of OPCs.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
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14
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Bharate SB, Guo L, Reeves TE, Cerasoli DM, Thompson CM. New series of monoquaternary pyridinium oximes: Synthesis and reactivation potency for paraoxon-inhibited electric eel and recombinant human acetylcholinesterase. Bioorg Med Chem Lett 2009; 19:5101-4. [PMID: 19640713 DOI: 10.1016/j.bmcl.2009.07.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 06/21/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
Abstract
The preparation of a series of monoquaternary pyridinium oximes bearing either a heterocyclic side chain or a functionalized aliphatic side chain and the corresponding in vitro evaluation for reactivation of paraoxon-inhibited electric eel acetylcholinesterase (EeAChE) and recombinant human acetylcholinesterase (rHuAChE) are reported. Several newly synthesized compounds efficiently reactivated inhibited EeAChE, but were poor reactivators of inhibited rHuAChE. Compounds bearing a thiophene ring in the side chain (20, 23, 26 and 29) showed better reactivation (24-37% for EeAChE and 5-9% for rHuAChE) compared to compounds with furan and isoxazole heterocycles (0-8% for EeAChE and 2-3% for rHuAChE) at 10(-5)M. The N-pyridyl-CH(2)COOH analog 8 reactivated EeAChE (36%) and rHuAChE (15%) at 10(-4)M with a k(r) value better than 2-pyridine aldoxime methiodide (2-PAM) for rHuAChE.
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Affiliation(s)
- Sandip B Bharate
- NIH COBRE Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
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Musilova L, Kuca K, jung YS, Jun D. In vitrooxime-assisted reactivation of paraoxon-inhibited human acetylcholinesterase and butyrylcholinesterase. Clin Toxicol (Phila) 2009; 47:545-50. [DOI: 10.1080/15563650903058914] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Kuca K, Cabal J, Jung YS, Musilek K, Soukup O, Jun D, Pohanka M, Musilova L, Karasová J, Novotný L, Hrabinova M. Reactivation of human brain homogenate cholinesterases inhibited by Tabun using newly developed oximes K117 and K127. Basic Clin Pharmacol Toxicol 2009; 105:207-10. [PMID: 19473310 DOI: 10.1111/j.1742-7843.2009.00421.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Newly developed acetylcholinesterase reactivators K117 [1,5-bis(4-hydroxyiminomethylpyridinium)-3-oxapentane dichloride] and K127 [(1-(4-hydroxyiminomethylpyridinium)-5-(4-carbamoylpyridinium)-3-oxapentane dibromide)] were tested for their potency to reactivate tabun-inhibited human brain cholinesterases. Pralidoxime and trimedoxime were chosen as standard reference reactivators. Human tissue was used, as that was closer on the real treatment of human beings. As a result, oxime K127 was found as the best tested reactivator according to the constant k(r), characterizing the overall reactivation process. On the contrary, the maximal reactivation ability expressed as percentage of reactivation was the best for trimedoxime. This differences were caused as a result of using the enzyme from different species. Due to this, experiments on human tissue should be conducted after in vitro and in vivo tests on animals to eliminate such important failures of promising oximes.
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Affiliation(s)
- Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defence, 500 01 Hradec Kralove, Czech Republic.
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Lorke DE, Nurulain SM, Hasan MY, Kuca K, Musilek K, Petroianu GA. Eight new bispyridinium oximes in comparison with the conventional oximes pralidoxime and obidoxime: in vivo efficacy to protect from diisopropylfluorophosphate toxicity. J Appl Toxicol 2008; 28:920-8. [PMID: 18548743 DOI: 10.1002/jat.1359] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In search for more efficacious reactivators of acetylcholinesterase (AChE) inhibited by organophosphorus compounds, experimental K-oximes have been synthesized which show good in vitro efficacy. However, AChE inhibition by oximes themselves (as quantified by their intrinsic IC50) is the major cause of oxime toxicity and the dose-limiting factor. To assess K-oxime efficacy in vivo, the extent of protection from mortality induced by diisopropylfluorophosphate (DFP) was quantified by Cox survival analysis and compared with that of the clinically available oximes. Oximes were administered in an equitoxic dosage, i.e. half the LD01. Best protection was conferred by K-27, reducing the relative risk of death (RR) to 16% of control RR (P < or = 0.05), which was statistically significantly better (P < or = 0.05) than all other tested oximes, except obidoxime, K-53 and K-75. The efficacy of obidoxime (RR = 0.19), K-48 (RR = 0.28), K-53 (RR = 0.22), K-74 (RR = 0.38) and K-75 (RR = 0.29) was significantly (P < or = 0.05) better than that of 2-PAM (RR = 0.62) and K-113 (RR = 0.73). No significant protective effect was observed for K-107 and K-108. Our LD50 data show that K-107, K-108 and K-113 (which strongly inhibit AChE in vitro) are in vivo markedly more toxic than all other oximes tested and can therefore only be safely administered at a low dosage which is insufficient to protect from DFP-induced mortality. Dosage calculations based on in vitro IC50 measurements may therefore in future replace in vivo LD50 determinations, thereby reducing the number of animals required.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, United Arab Emirates
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Musilek K, Holas O, Kuca K, Jun D, Dohnal V, Opletalova V, Dolezal M. Synthesis of monooxime-monocarbamoyl bispyridinium compounds bearing (E)-but-2-ene linker and evaluation of their reactivation activity against tabun- and paraoxon-inhibited acetylcholinesterase. J Enzyme Inhib Med Chem 2008; 23:70-6. [PMID: 18341256 DOI: 10.1080/14756360701383981] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Six AChE monooxime-monocarbamoyl reactivators with an (E)-but-2-ene linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and insecticide paraoxon was tested in vitro. The reactivation efficacies of pralidoxime, HI-6, obidoxime, K048, K075 and the newly prepared reactivators were compared. According to the results obtained, one reactivator seems to be promising against tabun-inhibited AChE and two reactivators against paraoxon-inhibited AChE. The best results were obtained for bisquaternary substances with at least one oxime group in position four.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic.
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Kuca K, Cabal J, Jun D, Koleckar V. In Vitro Comparison of Two Most Promising H-Oximes (HI-6 and HLö-7) and Currently Commercially Available Reactivators Pralidoxime and Obidoxime in Reactivation of Cyclosarin-Inhibited Human Cholinesterases. Toxicol Mech Methods 2008; 18:329-33. [DOI: 10.1080/15376510701380323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Musilek K, Holas O, Jun D, Dohnal V, Gunn-Moore F, Opletalova V, Dolezal M, Kuca K. Monooxime reactivators of acetylcholinesterase with (E)-but-2-ene linker—Preparation and reactivation of tabun- and paraoxon-inhibited acetylcholinesterase. Bioorg Med Chem 2007; 15:6733-41. [PMID: 17764957 DOI: 10.1016/j.bmc.2007.08.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 07/27/2007] [Accepted: 08/03/2007] [Indexed: 11/19/2022]
Abstract
Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Fifteen new monooxime reactivators of acetylcholinesterase with a (E)-but-2-ene linker were developed in an effort to extend the properties of K-oxime (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203). The known reactivators (pralidoxime, HI-6, obidoxime, K075, K203) and the new compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monooxime reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation comparable with known compounds for paraoxon poisoning. However, extensive differences were found by a SAR study for various substitutions on the non-oxime part of the reactivator molecule.
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Affiliation(s)
- Kamil Musilek
- Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05, Hradec Kralove, Czech Republic
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Targeted synthesis of 1-(4-hydroxyiminomethylpyridinium)-3-pyridiniumpropane dibromide--a new nerve agent reactivator. Molecules 2007; 12:1964-72. [PMID: 17960099 DOI: 10.3390/12081964] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 08/14/2007] [Accepted: 08/14/2007] [Indexed: 11/17/2022] Open
Abstract
Preparation of 1-(4-hydroxy-iminomethylpyridinium)-3-pyridiniumpropane dibromide is described. This compound represents a new acetylcholinesterase (AChE) reactivator, which has no substituents on the second pyridinium ring as found in other commonly used AChE reactivators. The reactivation ability of this reactivator was tested on tabun- and cyclosarin-inhibited AChE. According to the results obtained, the new compound (without substitution and with decreased molecule size) showed increased reactivation potency in case of cyclosarin inhibited AChE. A potent oxime for treatment of tabun and cyclosarin-caused intoxications was thus obtained via slight modification of the reactivator structure (compared to trimedoxime and K027).
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Musilek K, Kuca K, Dohnal V, Jun D, Marek J, Koleckar V. Two step synthesis of a non-symmetric acetylcholinesterase reactivator. Molecules 2007; 12:1755-61. [PMID: 17960085 PMCID: PMC6149169 DOI: 10.3390/12081755] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 08/01/2007] [Accepted: 08/06/2007] [Indexed: 11/16/2022] Open
Abstract
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.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Center of Advanced Studies, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Vlastimil Dohnal
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Department of Food Technology, Mendel University of Agriculture and Forestry Brno, Zemedelska 1, 613 00 Brno, Czech Republic
| | - Daniel Jun
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Center of Advanced Studies, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Jan Marek
- Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
| | - Vit Koleckar
- Center of Advanced Studies, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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Musilek K, Holas O, Kuca K, Jun D, Dohnal V, Opletalova V, Dolezal M. Novel series of bispyridinium compounds bearing a (Z)-but-2-ene linker—Synthesis and evaluation of their reactivation activity against tabun and paraoxon-inhibited acetylcholinesterase. Bioorg Med Chem Lett 2007; 17:3172-6. [PMID: 17383875 DOI: 10.1016/j.bmcl.2007.03.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 03/07/2007] [Accepted: 03/09/2007] [Indexed: 10/23/2022]
Abstract
Six novel AChE reactivators with a (Z)-but-2-ene linker were synthesized using the known synthetic pathways. Their ability to reactivate AChE, which had been previously inhibited by nerve agent tabun or pesticide paraoxon, was tested in vitro and compared to pralidoxime, HI-6, obidoxime, and K075. The novel synthesized compounds were found to be ineffective against GA-inhibited AChE but the ability of (Z)-1,4-bis(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide to reactivate paraoxon-inhibited AChE was comparable with that of oxime K075. Notably, the oxime group in position four substantially increased the ability of the novel compounds to reactivate paraoxon-inhibited AChE.
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Affiliation(s)
- Kamil Musilek
- Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
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