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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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2
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Bharate SB, Chao CK, Thompson CM. Comparison of the reactivation rates of acetylcholinesterase modified by structurally different organophosphates using novel pyridinium oximes. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2019; 71:103218. [PMID: 31302432 PMCID: PMC6736693 DOI: 10.1016/j.etap.2019.103218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/27/2019] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
A novel panel of oximes were synthesized, which have displayed varying degree of reactivation ability towards different organophosphorus (OP) modified cholinesterases. In the present article, we report a comparative reactivation profile of a series of quaternary pyridinium-oximes for electric eel acetylcholinesterase (EEAChE) inhibited by the organophosphorus (OP) inhibitors methyl paraoxon (MePOX), ethyl paraoxon (POX; paraoxon) and diisopropyl fluorophosphate (DFP) that are distinguishable as dimethoxyphosphoryl, diethoxyphosphoryl and diisopropoxyphosphoryl AChE-OP-adducts. Most of the 59-oximes tested led to faster and more extensive reactivation of MePOX- and POX-inhibited EEAChE as compared to DFP-modified EEAChE. All were effective reactivators of three OP-modified EEAChE conjugates showing 18-21% reactivation for DFP-inhibited AChE and ≥45% reactivation for MePOX- and POX-inhibited EEAChE. Oximes 7 and 8 showed kr values better than pralidoxime (1) for DFP-inhibited EEAChE. Reactivation rates determined at different inhibition times showed no significant change in kr values during 0-90 min incubation with three OPs. However, a 34-72% decrease in kr for MePOX and POX and > 95% decrease in kr for DFP-inhibited EEAChE was observed after 24 h of OP-exposure (aging).
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Affiliation(s)
- Sandip B Bharate
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, USA; Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
| | - Chih-Kai Chao
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, USA
| | - Charles M Thompson
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, USA.
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3
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Abstract
Standard therapy of Organophosphorus Compound (OPC) poisoning with
oxime-type acetylcholinesterase (AChE) reactivators is unsatisfactory. New bispyridinium
oximes have therefore been synthesized. This review summarizes in vitro characteristics
of established (pralidoxime, obidoxime, trimedoxime, HI-6) and experimental (K-)oximes,
and compares their protective efficacy in vivo, when administered shortly after exposure
to Diisopropylfluorophosphate (DFP) and three OPC pesticides (ethyl-paraoxon, methylparaoxon,
azinphos-methyl) in the same experimental setting.
In addition to reactivating cholinesterase, oximes also inhibit this enzyme; strongest
AChE inhibition (IC50 rat blood: 1-9 µM) is observed in vitro for the oximes with a xylene
linker (K-107, K-108, K-113). AChE inhibition is weakest for K-27, K-48 and HI-6 (IC50
>500 µM). Intrinsic AChE inhibition of oximes in vitro (IC50, rat) is strongly correlated with their LD50 (rat):
oximes with a high IC50 (K-27, K-48, pralidoxime, obidoxime) also show a high LD50, making them relatively
non-toxic, whereas oximes K-107, K-108 and K-113 (low IC50 and LD50) are far more toxic.
When given in vivo after OP exposure, best protection is conferred by K-27, reducing the relative risk of death
to 16-58% of controls, which is significantly superior to pralidoxime in DFP-, ethyl-paraoxon- and methylparaoxon-
exposure, and to obidoxime in ethyl-paraoxon- and methyl-paraoxon-exposure. Marked reduction in
mortality is also achieved by K-48, K-53, K-74 and K-75, whereas K-107, K-108 and K-113 have no or only a
very weak mortality-reducing effect. K-27 is the most promising K-oxime due to its strong reactivation potency,
weak cholinesterase inhibition and high LD50, allowing administration in large, very efficacious dosages.
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Affiliation(s)
- Dietrich E. Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, University Park GL 495 D, 11200 SW 8th St, Miami 33199, Florida , United States
| | - Georg A. Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, University Park GL 495 D, 11200 SW 8th St, Miami 33199, Florida , United States
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Lorke DE, Petroianu GA. The Experimental Oxime K027-A Promising Protector From Organophosphate Pesticide Poisoning. A Review Comparing K027, K048, Pralidoxime, and Obidoxime. Front Neurosci 2019; 13:427. [PMID: 31191210 PMCID: PMC6547910 DOI: 10.3389/fnins.2019.00427] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/15/2019] [Indexed: 11/13/2022] Open
Abstract
Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. In search of more efficacious broad-spectrum oximes, new bispyridinium (K-) oximes have been synthesized, with K027 being among the most promising. This review summarizes pharmacokinetic characteristics of K027, its toxicity and in vivo efficacy to protect from OPC toxicity and compares this oxime with another experimental bisquaternary asymmetric pyridinium aldoxime (K048) and two established oximes (pralidoxime, obidoxime). After intramuscular (i.m.) injection, K027 reaches maximum plasma concentration within ∼30 min; only ∼2% enter the brain. Its intrinsic cholinesterase inhibitory activity is low, making it relatively non-toxic. In vitro reactivation potency is high for ethyl-paraoxon-, methyl-paraoxon-, dichlorvos-, diisopropylfluorophosphate (DFP)- and tabun-inhibited cholinesterase. When administered in vivo after exposure to the same OPCs, K027 is comparable or more efficacious than pralidoxime and obidoxime. When given as a pretreatment before exposure to ethyl-paraoxon, methyl-paraoxon, DFP, or azinphos-methyl, it is superior to the Food and Drug Administration-approved compound pyridostigmine and comparable to physostigmine, which because of its entry into the brain may cause unwanted behavioral effects. Because of its low toxicity, K027 can be given in high dosages, making it a very efficacious oxime not only for postexposure treatment but also for prophylactic administration, especially when brain penetration is undesirable.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States.,Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Georg A Petroianu
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
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Ghosh S, Chandar NB, Jana K, Ganguly B. Revealing the importance of linkers in K-series oxime reactivators for tabun-inhibited AChE using quantum chemical, docking and SMD studies. J Comput Aided Mol Des 2017. [PMID: 28646405 DOI: 10.1007/s10822-017-0036-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Inhibition of acetylcholinesterase (AChE) with organophosphorus compounds has a detrimental effect on human life. Oxime K203 seems to be one of the promising reactivators for tabun-inhibited AChE than (K027, K127, and K628). These reactivators differ only in the linker units between the two pyridinium rings. The conformational analyses performed with quantum chemical RHF/6-31G* level for K027, K127, K203 and K628 showed that the minimum energy conformers have different orientations of the active and peripheral pyridinium rings for these reactivator molecules. K203 with (-CH2-CH=CH-CH2-) linker unit possesses more open conformation compared to the other reactivators. Such orientation of K203 experiences favorable interaction with the surrounding residues of catalytic anionic site (CAS) and peripheral anionic site (PAS) of tabun-inhibited AChE. From the steered molecular dynamics simulations, it has been observed that the oxygen atom of the oxime group of K203 reactivator approaches nearest to the P-atom of the SUN203 (3.75 Å) at lower time scales (less than ~1000 ps) as compared to the other reactivators. K203 experiences less number of hydrophobic interaction with the PAS residues which is suggested to be an important factor for the efficient reactivation process. In addition, K203 crates large number of H-bonding with CAS residues SUN203, Phe295, Tyr337, Phe338 and His447. K203 barely changes its conformation during the SMD simulation process and hence the energy penalty to adopt any other conformation is minimal in this case as compared to the other reactivators. The molecular mechanics and Poisson-Boltzmann surface area binding energies obtained for the interaction of K203 inside the gorge of tabun inhibited AChE is substantially higher (-290.2 kcal/mol) than the corresponding K628 reactivator (-260.4 kcal/mol), which also possess unsaturated aromatic linker unit.
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Affiliation(s)
- Shibaji Ghosh
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364 002, India.,Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, 364 002, India
| | - Nellore Bhanu Chandar
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364 002, India.,Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, 364 002, India
| | - Kalyanashis Jana
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364 002, India.,Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, 364 002, India
| | - Bishwajit Ganguly
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, 364 002, India. .,Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, 364 002, India.
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6
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Kassa J, Misik J, Hatlapatkova J, Zdarova Karasova J. A comparison of neuroprotective efficacy of two novel reactivators of acetylcholinesterase called K920 and K923 with the oxime K203 and trimedoxime in tabun-poisoned rats. Toxicol Mech Methods 2017; 27:236-243. [DOI: 10.1080/15376516.2016.1275907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Jiri Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jan Misik
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jana Hatlapatkova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jana Zdarova Karasova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
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7
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Kuca K, Korabecny J, Dolezal R, Nepovimova E, Soukup O, Gorecki L, Musilek K. Tetroxime: reactivation potency – in vitro and in silico study. RSC Adv 2017. [DOI: 10.1039/c6ra16499d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tetroxime – a unique bisquaternary compound with four oxime groups.
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Affiliation(s)
- K. Kuca
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Chemistry
- Faculty of Science
| | - J. Korabecny
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - R. Dolezal
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
| | - E. Nepovimova
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - O. Soukup
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
| | - L. Gorecki
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - K. Musilek
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Chemistry
- Faculty of Science
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8
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Sahu AK, Sharma R, Gupta B, Musilek K, Kuca K, Acharya J, Ghosh KK. Oxime-mediated in vitro reactivation kinetic analysis of organophosphates-inhibited human and electric eel acetylcholinesterase. Toxicol Mech Methods 2016; 26:319-26. [PMID: 27101948 DOI: 10.3109/15376516.2016.1143070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Organophosphate (OP)-based pesticides and nerve agents are highly toxic compounds which interrupt the catalytic mechanism of acetylcholinesterase (AChE) by phosphorylating the hydroxyl moiety of serine residue. The inhibited enzyme can be reactivated by the nucleophilic action of oxime reactivators. To analyze the effect of different AChE sources on reactivation efficacy of reactivators, several in vivo studies have carried out using variety of AChE sources like pig, rat and monkey. Investigations on species differences provide a better insight for the development of new reactivators. Hence, present study was mainly targeted on comparative analysis of the reactivation of electric eel and human AChE inhibited by different OP. A series of butene-linked bis-pyridinium mono oximes which vary in functional groups present at the second pyridinium ring have been examined against sarin, VX, tabun and ethyl-paraoxon-poisoned AChE. In case of tabun-inhibited AChEs, tested oximes were better than reference oximes. For VX-poisoned human AChE, reactivator K251 (kr2;1.51 mM (-) (1 )min (-) (1)) showed good reactivation efficacy with standard oximes. Studies stipulated that butene-linked oximes consisting of different functional moieties are good reactivators and found to have better efficacy to reactivate nerve agent-inhibited human AChE in comparison to eel AChE.
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Affiliation(s)
- Arvind Kumar Sahu
- a School of Studies in Chemistry, Pt. Ravishankar Shukla University , Raipur , India
| | - Rahul Sharma
- a School of Studies in Chemistry, Pt. Ravishankar Shukla University , Raipur , India
| | - Bhanushree Gupta
- a School of Studies in Chemistry, Pt. Ravishankar Shukla University , Raipur , India
| | - Kamil Musilek
- b Department of Chemistry , Faculty of Science, University of Hradec Kralove , Hradec Kralove , Czech Republic
| | - Kamil Kuca
- c Biomedical Research Center, University Hospital , Hradec Kralove , Czech Republic , and
| | - Jyotiranjan Acharya
- d Process Technology Development Division, Defence Research & Development Establishment , Gwalior, Madhya Pradesh , India
| | - Kallol K Ghosh
- a School of Studies in Chemistry, Pt. Ravishankar Shukla University , Raipur , India
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Kassa J, Sepsova V, Horova A, Musilek K. A comparison of the reactivating and therapeutic efficacy of two novel bispyridinium oximes (K920, K923) with the oxime K203 and trimedoxime in tabun-poisoned rats and mice. J Appl Biomed 2015. [DOI: 10.1016/j.jab.2015.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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10
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Winter M, Wille T, Musilek K, Kuca K, Thiermann H, Worek F. Investigation of the reactivation kinetics of a large series of bispyridinium oximes with organophosphate-inhibited human acetylcholinesterase. Toxicol Lett 2015. [PMID: 26210933 DOI: 10.1016/j.toxlet.2015.07.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The limited effectiveness of the established oximes obidoxime and pralidoxime resulted in ongoing research on novel oximes for the reactivation of acetylcholinesterase (AChE) inhibited by organophosphorus compounds (OP). In order to get more insight into the ability of bispyridinium oximes to reactivate human AChE inhibited by structurally different OP the reactivation kinetics of 31 compounds was determined with tabun-, cyclosarin- and paraoxon-inhibited AChE under identical experimental conditions. The determined affinity (KD), reactivity (kr) and hybrid reactivation rate constants (kr2) enabled theoretical calculations and gave insight into distinct structural features which are important for the reactivation of AChE inhibited by different OP. Several oximes with superior reactivating potency towards selective OP-AChE conjugates were identified but none of the tested oximes can be considered as a broad spectrum reactivator. In the end, the data of this and previous studies gives rise to the question whether further modifications of the bispyridinium structure could ever result in a universal reactivator or whether future research should be directed to different templates.
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Affiliation(s)
- Michael Winter
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Timo Wille
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Hradec Králové, Czech Republic
| | - Kamil Kuca
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Hradec Králové, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Center, Hradec Králové, Czech Republic
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany.
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Kassa J, Misik J, Zdarova Karasova J. Neuroprotective efficacy of newly developed oximes in comparison with currently available oximes in tabun-poisoned rats. J Appl Biomed 2015. [DOI: 10.1016/j.jab.2014.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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12
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Kassa J, Hatlapatková J, Žďárová Karasová J. The Evaluation of the Potency of Newly Developed Oximes (K727, K733) and Trimedoxime to Counteract Acute Neurotoxic Effects of Tabun in Rats. ACTA MEDICA (HRADEC KRÁLOVÉ) 2015; 58:135-43. [PMID: 26960827 DOI: 10.14712/18059694.2016.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIM The ability of two newly developed oximes (K727, K733) to reduce tabun-induced acute neurotoxic signs and symptoms was evaluated and compared with currently available trimedoxime in rats. METHODS The neuroprotective effects of the oximes studied combined with atropine on Wistar rats poisoned with tabun at a lethal dose (380 µg/kg i.m.; 90% of LD50 value) were evaluated. Tabun-induced neurotoxicity was monitored by the functional observational battery consisting of 38 measurements of sensory, motor and autonomic nervous functions at 2 hours following tabun challenge. RESULTS All tested oximes combined with atropine enable tabun-poisoned rats to survive till the end of experiment. Both newly developed oximes (K727, K733) combined with atropine were able to decrease tabun-induced neurotoxicity in the case of lethal poisoning although they did not eliminate all tabun-induced acute neurotoxic signs and symptoms. CONCLUSION The ability of both novel bispyridinium oximes to decrease tabun-induced acute neurotoxicity was slightly lower than that of trimedoxime. Therefore, the newly developed oximes are not suitable for the replacement of commonly used oximes such as trimedoxime in the treatment of acute tabun poisonings.
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Affiliation(s)
- Jiří Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic.
| | - Jana Hatlapatková
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
| | - Jana Žďárová Karasová
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
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Kassa J, Sepsova V, Tumova M, Horova A, Musilek K. A Comparison of the Reactivating and Therapeutic Efficacy of Two Newly Developed Oximes (K727 and K733) with Oxime K203 and Trimedoxime in Tabun-Poisoned Rats and Mice. Basic Clin Pharmacol Toxicol 2014; 116:367-71. [DOI: 10.1111/bcpt.12327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/08/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Jiri Kassa
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Vendula Sepsova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Martina Tumova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Anna Horova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Kamil Musilek
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
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14
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Kassa J, Sepsova V, Tumova M. A comparison of the reactivating and therapeutic efficacy of two novel oximes K378 and K458 with currently available oximes in rats and mice poisoned with sarin. J Appl Biomed 2014. [DOI: 10.1016/j.jab.2014.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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15
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Reactivation kinetics of 31 structurally different bispyridinium oximes with organophosphate-inhibited human butyrylcholinesterase. Arch Toxicol 2014; 89:405-14. [DOI: 10.1007/s00204-014-1288-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/28/2014] [Indexed: 02/02/2023]
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16
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Kassa J, Sepsova V, Tumova M, Musilek K, Horova A. The evaluation of the reactivating and therapeutic efficacy of two novel oximes (K361 and K378) in comparison with the oxime K203 and trimedoxime in tabun-poisoned rats and mice. Toxicol Mech Methods 2013; 24:173-8. [DOI: 10.3109/15376516.2013.871766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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17
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Acharya J, Rana H, Kaushik M. Synthesis and in vitro evaluation of xylene linked carbamoyl bis-pyridinium monooximes as reactivators of organophosphorus (OP) inhibited electric eel acetylcholinesterase (AChE). Eur J Med Chem 2011; 46:3926-33. [DOI: 10.1016/j.ejmech.2011.05.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/18/2011] [Accepted: 05/26/2011] [Indexed: 10/18/2022]
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18
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Musilek K, Pavlikova R, Marek J, Komloova M, Holas O, Hrabinova M, Pohanka M, Dohnal V, Dolezal M, Gunn-Moore F, Kuca K. The preparation, in vitro screening and molecular docking of symmetrical bisquaternary cholinesterase inhibitors containing a but-(2E)-en-1,4-diyl connecting linkage. J Enzyme Inhib Med Chem 2011; 26:245-53. [DOI: 10.3109/14756366.2010.496362] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Kamil Musilek
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Trebesska 1575, Hradec Kralove, Czech Republic
- University of Jan Evangelista Purkynje, Faculty of Science, Department of Chemistry, Ceske mladeze 8, Usti nad Labem, Czech Republic
| | - Ruzena Pavlikova
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Trebesska 1575, Hradec Kralove, Czech Republic
| | - Jan Marek
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Trebesska 1575, Hradec Kralove, Czech Republic
| | - Marketa Komloova
- Charles University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry and Drug Control, Heyrovskeho 1203, Hradec Kralove, Czech Republic
| | - Ondrej Holas
- Charles University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry and Drug Control, Heyrovskeho 1203, Hradec Kralove, Czech Republic
| | - Martina Hrabinova
- University of Defence, Faculty of Military Health Sciences, Centre of Advanced Studies, Trebesska 1575, Hradec Kralove, Czech Republic
| | - Miroslav Pohanka
- University of Defence, Faculty of Military Health Sciences, Centre of Advanced Studies, Trebesska 1575, Hradec Kralove, Czech Republic
| | - Vlastimil Dohnal
- University of Jan Evangelista Purkynje, Faculty of Science, Department of Chemistry, Ceske mladeze 8, Usti nad Labem, Czech Republic
| | - Martin Dolezal
- Charles University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry and Drug Control, Heyrovskeho 1203, Hradec Kralove, Czech Republic
| | - Frank Gunn-Moore
- University of St. Andrews, School of Biology, Bute Building, St. Andrews, Fife, UK
| | - Kamil Kuca
- University of Defence, Faculty of Military Health Sciences, Centre of Advanced Studies, Trebesska 1575, Hradec Kralove, Czech Republic
- University of Jan Evangelista Purkynje, Faculty of Science, Department of Chemistry, Ceske mladeze 8, Usti nad Labem, Czech Republic
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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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20
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Musilek K, Roder J, Komloova M, Holas O, Hrabinova M, Pohanka M, Dohnal V, Opletalova V, Kuca K, Jung YS. Preparation, in vitro screening and molecular modelling of symmetrical 4-tert-butylpyridinium cholinesterase inhibitors--analogues of SAD-128. Bioorg Med Chem Lett 2010; 21:150-4. [PMID: 21144749 DOI: 10.1016/j.bmcl.2010.11.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 11/06/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
Abstract
Carbamate inhibitors (e.g., pyridostimine bromide) are used as a pre-exposure treatment for the prevention of organophosphorus poisoning. They work by blocking acetylcholinesterase's (AChE) native function and thus protect AChE against irreversible inhibition by organophosphorus compounds. However, carbamate inhibitors are known for many undesirable side-effects related to the carbamylation of AChE. In this Letter, 19 analogues of SAD-128 were prepared and evaluated as cholinesterase inhibitors. The screening results showed promising inhibitory ability of four compounds better to used standards (pralidoxime, obidoxime, BW284c51, ethopropazine, SAD-128). Four most promising compounds were selected for further molecular docking studies. The SAR was stated from obtained data. The former receptor studies were reported and discussed. The further in vivo studies were recommended in the view of OP pre-exposure treatment.
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Affiliation(s)
- Kamil Musilek
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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21
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Soukup O, Kristofikova Z, Proska J, Tobin G, Patocka J, Marek J, Jun D, Fusek J, Ripova D, Kuca K. Novel acetylcholinesterase reactivator K112 and its cholinergic properties. Biomed Pharmacother 2010; 64:541-5. [DOI: 10.1016/j.biopha.2010.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 01/08/2010] [Indexed: 10/19/2022] Open
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22
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Kassa J, Karasova JZ, Kuca K, Musilek K. A comparison of the reactivating and therapeutic efficacy of newly developed oximes (K347, K628) with commonly used oximes (obidoxime, HI-6) against tabun in rats and mice. Drug Chem Toxicol 2010; 33:227-32. [PMID: 20429807 DOI: 10.3109/01480540903483409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The potency of newly developed reactivators of nerve agent-inhibited acetylcholinesterase (K347, K628) in reactivating tabun-inhibited acetylcholinesterase and reducing tabun-induced lethal toxic effects was compared with currently available oximes (obidoxime, the oxime HI-6), using in vivo methods. Studies that determined the percentage of reactivation of tabun-inhibited blood and tissue acetycholinesterase in poisoned rats showed that the reactivating efficacy of both newly developed oximes is comparable with the oxime HI-6, but it is significantly lower than the reactivating effects of obidoxime. The monopyridinium oxime, K347, was also found to be able to reduce lethal toxic effects in tabun-poisoned mice, while the therapeutic efficacy of another newly developed bispyridinium oxime, K628, was negligible. The therapeutic efficacy of K347 was higher than the potency of the oxime, HI-6, but it was lower than the therapeutic effects of obidoxime. Thus, the reactivating and therapeutic potency of both newly developed oximes (K347, K628) was not more effective then currently available oximes, and therefore, they are not suitable for the replacement of commonly used oximes (especially obidoxime) for the treatment of acute tabun poisoning.
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Affiliation(s)
- Jiri Kassa
- Department of Toxicology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic.
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23
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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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24
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Kassa J, Karasova JZ, Caisberger F, Musilek K, Kuca K, Jung YS. A comparison of reactivating and therapeutic efficacy of the oxime K203 and its fluorinated analog (KR-22836) with currently available oximes (obidoxime, trimedoxime, HI-6) against tabun in rats and mice. J Enzyme Inhib Med Chem 2010; 25:480-4. [DOI: 10.3109/14756360903257918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jiri Kassa
- Department of Toxicology, Hradec Kralove, Czech Republic
| | | | - Filip Caisberger
- Department of Anatomy, Faculty of Medicine, Charles University, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Department of Toxicology, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Young-Sik Jung
- Medicinal Science Division, Korea Research Institute of Chemical Technology, Yusong, Daejeon, Korea
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Musilek K, Holas O, Misik J, Pohanka M, Novotny L, Dohnal V, Opletalova V, Kuca K. Monooxime-monocarbamoyl Bispyridinium Xylene-Linked Reactivators of Acetylcholinesterase-Synthesis, In vitro and Toxicity Evaluation, and Docking Studies. ChemMedChem 2010; 5:247-54. [DOI: 10.1002/cmdc.200900455] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Bharate SB, Guo L, Reeves TE, Cerasoli DM, Thompson CM. Bisquaternary pyridinium oximes: Comparison of in vitro reactivation potency of compounds bearing aliphatic linkers and heteroaromatic linkers for paraoxon-inhibited electric eel and recombinant human acetylcholinesterase. Bioorg Med Chem 2010; 18:787-94. [PMID: 20005727 PMCID: PMC2818686 DOI: 10.1016/j.bmc.2009.11.052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Revised: 11/18/2009] [Accepted: 11/21/2009] [Indexed: 11/26/2022]
Abstract
Oxime reactivators are the drugs of choice for the post-treatment of OP (organophosphorus) intoxication and used widely for mechanistic and kinetic studies of OP-inhibited cholinesterases. The purpose of the present study was to evaluate new oxime compounds to reactivate acetylcholinesterase (AChE) inhibited by the OP paraoxon. Several new bisquaternary pyridinium oximes with heterocyclic linkers along with some known bisquaternary pyridinium oximes bearing aliphatic linkers were synthesized and evaluated for their in vitro reactivation potency against paraoxon-inhibited electric eel acetylcholinesterase (EeAChE) and recombinant human acetylcholinesterase (rHuAChE). Results herein indicate that most of the compounds are better reactivators of EeAChE than of rHuAChE. The reactivation potency of two different classes of compounds with varying linker chains was compared and observed that the structure of the connecting chain is an important factor for the activity of the reactivators. At a higher concentration (10(-3)M), compounds bearing aliphatic linker showed better reactivation than compounds with heterocyclic linkers. Interestingly, oximes with a heterocyclic linker inhibited AChE at higher concentration (10(-3)M), whereas their ability to reactivate was increased at lower concentrations (10(-4)M and 10(-5)M). Compounds bearing either a thiophene linker 26, 46 or a furan linker 31 showed 59%, 49% and 52% reactivation of EeAChE, respectively, at 10(-5)M. These compounds showed 14%, 6% and 15% reactivation of rHuAChE at 10(-4)M. Amongst newly synthesized analogs with heterocyclic linkers (26-35 and 45-46), compound 31, bearing furan linker chain, was found to be the most effective reactivator with a k(r) 0.042min(-1), which is better than obidoxime (3) for paraoxon-inhibited EeAChE. Compound 31 showed a k(r) 0.0041min(-1) that is near equal to pralidoxime (1) for paraoxon-inhibited 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
| | - Lilu Guo
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Tony E. Reeves
- USAMRICD, Research Division, Physiology and Immunology Branch, 3100 Ricketts Point Road, APG, MD 21010, USA
| | - Douglas M. Cerasoli
- USAMRICD, Research Division, Physiology and Immunology Branch, 3100 Ricketts Point Road, APG, MD 21010, USA
| | - Charles M. Thompson
- NIH COBRE Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
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27
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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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28
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Kuca K, RC G, Musilek K, Jun D, Pohanka M. In vitro identification of novel acetylcholinesterase reactivators. TOXIN REV 2009. [DOI: 10.3109/15569540903246144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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29
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Lorke DE, Petroianu GA. Minireview: does in-vitro testing of oximes help predict their in-vivo action after paraoxon exposure? J Appl Toxicol 2009; 29:459-69. [PMID: 19603416 DOI: 10.1002/jat.1457] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
K-oximes have recently been developed in the search for efficacious broad-band reactivators of acetylcholinesterase (AChE) inhibited by organophosphorus compounds (OPC). Before clinical use, their toxicity and efficacy need to be assessed, and there is clear demand for simple in vitro tests that can predict in vivo performance. This article summarizes our in vitro data obtained for conventional and experimental oximes in human and rat blood exposed to the OPC paraoxon and correlates them with our in vivo results. The intrinsic AChE inhibitory activity of oximes, as reflected by their in vitro IC(50), is strongly correlated with their LD(50) (rat): oximes with a high IC(50) (K-27, K-48, pralidoxime and obidoxime) also show a high LD(50) and are thus relatively non-toxic, whereas oximes K-105, K-108 and K-113 have a low IC(50), a low LD(50) and are far more toxic. The IC(50) is also correlated with the in vivo capacity to protect from paraoxon-induced mortality: oximes with a higher IC(50) reduce the relative risk of death more. In contrast, the protective ability as assessed in vitro by the slope of the IC(50) shift (tanalpha), is not correlated with in vivo protection from paraoxon-induced mortality: the best in vivo protectors (K-27 and K-48) show a much lower tanalpha value (around 2) than K-110 and K-113 (tanalpha around 10), which hardly reduce the relative risk of death after paraoxon exposure. The partition coefficient logP of the individual oximes is inversely correlated with their IC(50) and with their LD(50) and is therefore an indicator of toxicity: strongly hydrophilic oximes tend to be less toxic than less hydrophilic ones. These data highlight the good predictive value of in vitro IC(50) testing for in vivo toxicity and the limited practical significance of in vitro assessment of protective potency.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, UAE
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REACTIVATION POTENCY OF THE ACETYLCHOLINESTERASE REACTIVATOR OBIDOXIME IS LIMITED. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2009; 153:259-62. [DOI: 10.5507/bp.2009.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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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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32
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Kassa J, Karasova J, Bajgar J, Kuca K, Musilek K, Kopelikova I. A comparison of the reactivating and therapeutic efficacy of newly developed bispyridinium oximes (K250, K251) with commonly used oximes against tabun in rats and mice. J Enzyme Inhib Med Chem 2009; 24:1040-4. [DOI: 10.1080/14756360802608419] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Jiri Kassa
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Jana Karasova
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Jiri Bajgar
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Irena Kopelikova
- Faculty of Pharmacy, Charles University, Hradec Kralove, Czech Republic
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Efficacy of eight experimental bispyridinium oximes against paraoxon-induced mortality: comparison with the conventional oximes pralidoxime and obidoxime. Neurotox Res 2009; 16:60-7. [PMID: 19526299 DOI: 10.1007/s12640-009-9048-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 06/25/2008] [Accepted: 06/25/2008] [Indexed: 10/20/2022]
Abstract
Recently, several experimental K-oximes with two functional aldoxime groups have been synthesized that show excellent in vitro efficacy in protecting acetylcholinesterase (AChE) from inhibition by a broad variety of organophosphorus compounds (OPCs). However, oximes themselves are also AChE inhibitors, albeit at higher concentrations, which is a major cause of their toxicity and may be a dose-limiting factor in oxime therapy. To assess the efficacy of the experimental K-oximes in vivo, the extent of oxime-conferred protection from mortality induced by paraoxon was quantified. Rats received paraoxon in a dosage of 1, 5, or 10 mumol, and immediately thereafter intraperitoneal injections of the respective oxime at a dosage of half the LD(01). The relative risk of death (RR) over time was estimated by Cox survival analysis for treatment with experimental K-oximes (K-53, K-74, K-75, K-107, K-108, and K-113), with the clinically available oximes pralidoxime (2-PAM) and obidoxime, and with the well-characterized K-oximes K-27 and K-48, comparing results with the no-treatment group. Best protection was conferred by K-27, reducing the RR to 20% of controls (P </= 0.05), which was significantly (P <or= 0.05) better than all other tested oximes. Marked reduction in mortality was also achieved by K-48 and the three new bispyridinium oximes containing two aldoxime groups, but no xylene linker: K-48 (RR = 0.32), K-53 (RR = 0.36), K-74 (RR = 0.42), K-75 (RR = 0.35). This effect was significantly (P <or= 0.05) superior to that of all other oximes, except K-27. The remaining oximes, i.e., obidoxime (RR = 0.64), 2-PAM (RR = 0.78), K-107 (RR = 0.70), K-108 (RR = 0.77), and K-113 (RR = 0.87) reduced paraoxon-induced mortality only poorly, but significantly (P <or= 0.05). Our data show that K-27, K-48, K-53, K-74, and K-75, due to their far superior in vivo efficacy, are the most promising candidates to eventually replace the established oximes 2-PAM and obidoxime. Further studies in other species exposed to a broader spectrum of OPCs are, however, necessary before considering their use in humans.
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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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35
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Pohanka M, Jun D, Kuca K. Photometric microplate assay for estimation of the efficacy of paraoxon-inhibited acetylcholinesterase reactivation. J Enzyme Inhib Med Chem 2008; 23:781-4. [DOI: 10.1080/14756360701811023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Miroslav Pohanka
- Centre of Biological Defence, Central Military Institute of Health, Techonin, Czech Republic
| | - Daniel Jun
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
- Department of Toxicology, Faculty of Military Medicine, University of Defense, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
- Department of Toxicology, Faculty of Military Medicine, University of Defense, Hradec Kralove, Czech Republic
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36
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Kassa J, Karasova J, Bajgar J, Kuca K, Musilek K. A comparison of the therapeutic and reactivating efficacy of newly developed bispyridinium compounds (K206, K269) with currently available oximes against tabun in rats and mice. J Enzyme Inhib Med Chem 2008; 23:776-80. [DOI: 10.1080/14756360701809902] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Jiri Kassa
- Department of Toxicology, Faculty of Military Health Sciences, Hradec, Kralove, Czech Republic
| | - Jana Karasova
- Department of Toxicology, Faculty of Military Health Sciences, Hradec, Kralove, Czech Republic
| | - Jiri Bajgar
- Department of Toxicology, Faculty of Military Health Sciences, Hradec, Kralove, Czech Republic
| | - Kamil Kuca
- Department of Toxicology, Faculty of Military Health Sciences, Hradec, Kralove, Czech Republic
| | - Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Hradec, Kralove, Czech Republic
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Musilek K, Kucera J, Jun D, Dohnal V, Opletalova V, Kuca K. Monoquaternary pyridinium salts with modified side chain-synthesis and evaluation on model of tabun- and paraoxon-inhibited acetylcholinesterase. Bioorg Med Chem 2008; 16:8218-23. [PMID: 18676153 DOI: 10.1016/j.bmc.2008.07.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 07/08/2008] [Accepted: 07/16/2008] [Indexed: 10/21/2022]
Abstract
Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Eighteen monoquaternary reactivators of acetylcholinesterase with modified side chain were developed in an effort to extend the properties of pralidoxime. The known reactivators (pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) and the prepared compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monoquaternary reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation better or comparable with pralidoxime for paraoxon poisoning. However, extensive differences were found by a SAR study for various side chains on the non-oxime part of the reactivator molecule.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic.
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Kassa J, Karasova J, Musilek K, Kuca K. An evaluation of therapeutic and reactivating effects of newly developed oximes (K156, K203) and commonly used oximes (obidoxime, trimedoxime, HI-6) in tabun-poisoned rats and mice. Toxicology 2008; 243:311-6. [DOI: 10.1016/j.tox.2007.10.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 10/17/2007] [Accepted: 10/20/2007] [Indexed: 11/26/2022]
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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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