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Thakur A, Patwa J, Sharma A, Flora SJ. Synthesis, Molecular Docking, BSA, and in-vitro reactivation study of imidazopyridine oxime against paraoxon inhibited acetylcholinesterase. Med Chem 2021; 18:273-287. [PMID: 33563155 DOI: 10.2174/1573406417666210208223240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 11/22/2022]
Abstract
AIM To synthesize and evaluate the fused heterocyclic imidazopyridine oxime as a reactivator against paraoxon inhibited acetylcholinesterase. BACKGROUND Organophosphorus compounds (OPs) include parathion, malathion, chlorpyrifos, monocrotophos, and diazinon which are commonly used in agriculture for enhancing agricultural productivity via killing crop-damaging pests. However, people may get exposed to OPs pesticides unintentionally/intentionally via ingestion, inhalation or dermal. The current treatment regimen includes reactivator such as mono or bis-pyridinium oximes along with anticholinergic and an anticonvulsant drugs are recommended for the treatment of OP poisoning. Unfortunately, the drawback of the existing reactivator is that owing to the permanent charge present on the pyridinium makes them inefficient to cross the blood-brain barrier (BBB) and reactivate OP-inhibited central nervous system (CNS) acetylcholinesterase. Therefore, there is a need of reactivator that could cross the BBB and reactivate the OP inhibited acetylcholinesterase. OBJECTIVE The objectives of the study were synthesis, molecular docking, BSA binding and in-vitro estimation of oximes of various substituted imidazo [1,2-a]pyridine against paraoxon inhibited acetylcholinesterase. METHOD The reactivators were synthesized in three steps and characterized using various spectroscopic techniques. Molecular docking study was performed on 2WHP and 3ZLV PDB using Autodock tool. The acid dissociation constant (pKa) of oximes was calculated experimentally and drug-likeness properties of the oximes were calculated In silico using mole inspiration and Swiss ADME software. The binding of oximes with bovine serum albumin (BSA) was also investigated by UV-Vis spectrophotometer. The reactivation potential of the oximes was determined by in vitro enzymatic assay. RESULT in-silico study inferred that synthesized molecules fulfilled the parameters that required for a successful CNS drug candidate. Further, in-vitro enzymatic assay indicated reasonable reactivation potential of the oximes against paraoxon-inhibited AChE. The binding of oximes with bovine serum albumin (BSA) revealed static quenching of intrinsic fluorescence of BSA by oxime. The binding constant value and number of binding sites were found 0.24 mol-1 and 1 respectively. CONCLUSION The results of study concluded that this scaffold could be used for further designing of more efficient uncharged reactivators.
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Affiliation(s)
- Ashima Thakur
- Department of Medicinal Chemistry and Toxicology, National Institute of Pharmaceutical Education and Research, Bijnor-Sisendi Road, Near CRPF Base Camp, Sarojini Nagar, Lucknow, Uttar Pradesh 226301, . India
| | - Jayant Patwa
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Bijnor-Sisendi Road, Near CRPF Base Camp, Sarojini Nagar, Lucknow, Uttar Pradesh 226301, . India
| | - Abha Sharma
- Department of Medicinal Chemistry and Toxicology, National Institute of Pharmaceutical Education and Research, Bijnor-Sisendi Road, Near CRPF Base Camp, Sarojini Nagar, Lucknow, Uttar Pradesh 226301, . India
| | - Swaran Jeet Flora
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Bijnor-Sisendi Road, Near CRPF Base Camp, Sarojini Nagar, Lucknow, Uttar Pradesh 226301, . India
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Musílek K, Kuča K, Jun D. Evaluation of Potency of Known Oximes (Pralidoxime, Trimedoxime, HI-6, Methoxime, Obidoxime) to in vitro Reactivate Acetylcholinesterase Inhibited by Pesticides (Chlorpyrifos and Methylchlorpyrifos and Nerve Agent (Russian VX). ACTA MEDICA (HRADEC KRÁLOVÉ) 2017. [DOI: 10.14712/18059694.2017.83] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Nerve agents and pesticides belong to the group of organophosphates. They are able to inhibit irreversibly the enzyme acetylcholinesterase (AChE). Acetylcholinesterase reactivators were designed for the treatment of nerve agent intoxications. Their potency to reactivate pesticide-inhibited AChE was many times evaluated. In this study, five commonly used AChE reactivators (pralidoxime, methoxime, HI-6, obidoxime, trimedoxime) for the reactivation of AChE inhibited by two pesticides (chlorpyrifos and methylchlorpyrifos) were used. Russian VX (nerve agent) as a member of nerve agents’ family was taken for comparison. Obtained results show that oximes developed against nerve agent intoxication are less effective for intoxication with organophosphorus pesticides. Especially, methylchlorpyrifos-inhibited AChE was found to be poorly reactivated by the compounds used.
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Janockova J, Zilecka E, Kasparkova J, Brabec V, Soukup O, Kuca K, Kozurkova M. Assessment of DNA-binding affinity of cholinesterase reactivators and electrophoretic determination of their effect on topoisomerase I and II activity. MOLECULAR BIOSYSTEMS 2017; 12:2910-20. [PMID: 27412811 DOI: 10.1039/c6mb00332j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper, we describe the biochemical properties and biological activity of a series of cholinesterase reactivators (symmetrical bisquaternary xylene-linked compounds, K106-K114) with ctDNA. The interaction of the studied derivatives with ctDNA was investigated using UV-Vis, fluorescence, CD and LD spectrometry, and electrophoretic and viscometric methods. The binding constants K were estimated to be in the range 1.05 × 10(5)-5.14 × 10(6) M(-1) and the percentage of hypochromism was found to be 10.64-19.28% (from UV-Vis titration). The used methods indicate that the studied samples are groove binders. Electrophoretic methods proved that the studied compounds clearly influence calf thymus Topo I (at 5 μM concentration, except for compounds K107, K111 and K114 which were effective at higher concentrations) and human Topo II (K110 partially inhibited Topo II effects even at 5 μM concentration) activity.
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Affiliation(s)
- J Janockova
- Institute of Chemistry, Department of Biochemistry, Faculty of Science, P. J. Safarik University, Moyzesova 11, 040 01 Kosice, Slovak Republic. and Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - E Zilecka
- Institute of Chemistry, Department of Biochemistry, Faculty of Science, P. J. Safarik University, Moyzesova 11, 040 01 Kosice, Slovak Republic.
| | - J Kasparkova
- Department of Biophysics, Faculty of Science, Palacky University, Slechtitelu 27, 783 71 Olomouc, Czech Republic
| | - V Brabec
- Department of Biophysics, Faculty of Science, Palacky University, Slechtitelu 27, 783 71 Olomouc, Czech Republic
| | - O Soukup
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - K Kuca
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - M Kozurkova
- Institute of Chemistry, Department of Biochemistry, Faculty of Science, P. J. Safarik University, Moyzesova 11, 040 01 Kosice, Slovak Republic. and Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
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4
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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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Gorecki L, Korabecny J, Musilek K, Malinak D, Nepovimova E, Dolezal R, Jun D, Soukup O, Kuca K. SAR study to find optimal cholinesterase reactivator against organophosphorous nerve agents and pesticides. Arch Toxicol 2016; 90:2831-2859. [PMID: 27582056 DOI: 10.1007/s00204-016-1827-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 08/22/2016] [Indexed: 01/13/2023]
Abstract
Irreversible inhibition of acetylcholinesterase (AChE) by organophosphates leads to many failures in living organism and ultimately in death. Organophosphorus compounds developed as nerve agents such as tabun, sarin, soman, VX and others belong to the most toxic chemical warfare agents and are one of the biggest threats to the modern civilization. Moreover, misuse of nerve agents together with organophosphorus pesticides (e.g. malathion, paraoxon, chlorpyrifos, etc.) which are annually implicated in millions of intoxications and hundreds of thousand deaths reminds us of insufficient protection against these compounds. Basic treatments for these intoxications are based on immediate administration of atropine and acetylcholinesterase reactivators which are currently represented by mono- or bis-pyridinium aldoximes. However, these antidotes are not sufficient to ensure 100 % treatment efficacy even they are administered immediately after intoxication, and in general, they possess several drawbacks. Herein, we have reviewed new efforts leading to the development of novel reactivators and proposition of new promising strategies to design novel and effective antidotes. Structure-activity relationships and biological activities of recently proposed acetylcholinesterase reactivators are discussed and summarized. Among further modifications of known oximes, the main attention has been paid to dual binding site ligands of AChE as the current mainstream strategy. We have also discussed new chemical entities as potential replacement of oxime functional group.
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Affiliation(s)
- Lukas Gorecki
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - David Malinak
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Physiology and Pathophysiology, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00, Ostrava, Czech Republic
| | - Eugenie Nepovimova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Rafael Dolezal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Daniel Jun
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic. .,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic.
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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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Wilhelm CM, Snider TH, Babin MC, Jett DA, Platoff GE, Yeung DT. A comprehensive evaluation of the efficacy of leading oxime therapies in guinea pigs exposed to organophosphorus chemical warfare agents or pesticides. Toxicol Appl Pharmacol 2014; 281:254-65. [PMID: 25448441 DOI: 10.1016/j.taap.2014.10.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 11/28/2022]
Abstract
The currently fielded pre-hospital therapeutic regimen for the treatment of organophosphorus (OP) poisoning in the United States (U.S.) is the administration of atropine in combination with an oxime antidote (2-PAM Cl) to reactivate inhibited acetylcholinesterase (AChE). Depending on clinical symptoms, an anticonvulsant, e.g., diazepam, may also be administered. Unfortunately, 2-PAM Cl does not offer sufficient protection across the range of OP threat agents, and there is some question as to whether it is the most effective oxime compound available. The objective of the present study is to identify an oxime antidote, under standardized and comparable conditions, that offers protection at the FDA approved human equivalent dose (HED) of 2-PAM Cl against tabun (GA), sarin (GB), soman (GD), cyclosarin (GF), and VX, and the pesticides paraoxon, chlorpyrifos oxon, and phorate oxon. Male Hartley guinea pigs were subcutaneously challenged with a lethal level of OP and treated at approximately 1 min post challenge with atropine followed by equimolar oxime therapy (2-PAM Cl, HI-6 DMS, obidoxime Cl₂, TMB-4, MMB4-DMS, HLö-7 DMS, MINA, and RS194B) or therapeutic-index (TI) level therapy (HI-6 DMS, MMB4-DMS, MINA, and RS194B). Clinical signs of toxicity were observed for 24 h post challenge and blood cholinesterase [AChE and butyrylcholinesterase (BChE)] activity was analyzed utilizing a modified Ellman's method. When the oxime is standardized against the HED of 2-PAM Cl for guinea pigs, the evidence from clinical observations, lethality, quality of life (QOL) scores, and cholinesterase reactivation rates across all OPs indicated that MMB4 DMS and HLö-7 DMS were the two most consistently efficacious oximes.
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Affiliation(s)
| | - Thomas H Snider
- Battelle, 505 King Avenue, JM-7, Columbus, OH 43201-2693, USA.
| | - Michael C Babin
- Battelle, 505 King Avenue, JM-7, Columbus, OH 43201-2693, USA.
| | - David A Jett
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
| | - Gennady E Platoff
- National Institutes of Health/National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.
| | - David T Yeung
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
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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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Konidaris KF, Dalkas GA, Katsoulakou E, Pairas G, Raptopoulou CP, Lamari FN, Spyroulias GA, Manessi-Zoupa E. ZnII/pyridyloxime complexes as potential reactivators of OP-inhibited acetylcholinesterase: In vitro and docking simulation studies. J Inorg Biochem 2014; 134:12-9. [DOI: 10.1016/j.jinorgbio.2013.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/26/2013] [Accepted: 12/26/2013] [Indexed: 10/25/2022]
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Janockova J, Gulasova Z, Musilek K, Kuca K, Kozurkova M. Novel cholinesterase modulators and their ability to interact with DNA. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 115:364-369. [PMID: 23851179 DOI: 10.1016/j.saa.2013.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/23/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
In the present work, an interaction of four cholinesterase modulators (1-4) with calf thymus DNA was studied via spectroscopic techniques (UV-Vis, fluorescent spectroscopy and circular dichroism). From UV-Vis spectroscopic analysis, the binding constants for DNA-pyridinium oximes complexes were calculated (K=3.5×10(4) to 1.4×10(5)M(-1)). All these measurements indicated that the compounds behave as effective DNA-interacting agents. Electrophoretic techniques proved that ligand 2 inhibited topoisomerase I at a concentration 5μM.
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Affiliation(s)
- Jana Janockova
- Institute of Chemistry, Department of Biochemistry, P.J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
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Bajgar J. Optimal choice of acetylcholinesterase reactivators for antidotal treatment of nerve agent intoxication. ACTA MEDICA (HRADEC KRÁLOVÉ) 2011; 53:207-11. [PMID: 21400978 DOI: 10.14712/18059694.2016.78] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The studies dealing with mechanism of organophosphates (OP)/nerve agent action, prophylaxis and treatment of intoxications is a very hot topic at present. Though the research is very intensive, unfortunately, up to now, there is not universal or significantly better reactivator sufficiently effective against all nerve agents/OP when compared with presently available oximes (pralidoxime, methoxime, obidoxime, trimedoxime, HI-6). The use of the most effective reactivator (HI-6) using simple type of autoinjector (e.g. ComboPen) is strictly limited because of decomposition of HI-6 in solution. Thanks to better solubility it is clear that another salt of HI-6 (dimethanesulfonate, HI-6 DMS) is more convenient for the use as antidote against nerve agents in the autoinjector than HI-6 chloride (Cl). It was clearly demonstrated that reactivation potency of HI-6 DMS in comparison with HI-6 Cl in vivo was the same and bioavailability of HI-6 DMS is better than that of HI-6 Cl. Three chambered autoinjector allows administration of all three antidotes (atropine, reactivator, diazepam) simultaneously. Moreover, the content of chambers can be changed according to proposed requirements. Possible way to solve the problem of universal reactivator could be the use of two reactivators. Three chambered autoinjector is an ideal device for this purpose.
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Affiliation(s)
- Jirí Bajgar
- Department of Toxicology, University of Defence in Brno, Faculty of Military Health Sciences, Hradec Králové, Czech Republic.
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Jun D, Musilova L, Musilek K, Kuca K. In vitro ability of currently available oximes to reactivate organophosphate pesticide-inhibited human acetylcholinesterase and butyrylcholinesterase. Int J Mol Sci 2011; 12:2077-87. [PMID: 21673941 PMCID: PMC3111652 DOI: 10.3390/ijms12032077] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 03/09/2011] [Indexed: 11/16/2022] Open
Abstract
We have in vitro tested the ability of common, commercially available, cholinesterase reactivators (pralidoxime, obidoxime, methoxime, trimedoxime and HI-6) to reactivate human acetylcholinesterase (AChE), inhibited by five structurally different organophosphate pesticides and inhibitors (paraoxon, dichlorvos, DFP, leptophos-oxon and methamidophos). We also tested reactivation of human butyrylcholinesterase (BChE) with the aim of finding a potent oxime, suitable to serve as a “pseudocatalytic” bioscavenger in combination with this enzyme. Such a combination could allow an increase of prophylactic and therapeutic efficacy of the administered enzyme. According to our results, the best broad-spectrum AChE reactivators were trimedoxime and obidoxime in the case of paraoxon, leptophos-oxon, and methamidophos-inhibited AChE. Methamidophos and leptophos-oxon were quite easily reactivatable by all tested reactivators. In the case of methamidophos-inhibited AChE, the lower oxime concentration (10−5 M) had higher reactivation ability than the 10−4 M concentration. Therefore, we evaluated the reactivation ability of obidoxime in a concentration range of 10−3–10−7 M. The reactivation of methamidophos-inhibited AChE with different obidoxime concentrations resulted in a bell shaped curve with maximum reactivation at 10−5 M. In the case of BChE, no reactivator exceeded 15% reactivation ability and therefore none of the oximes can be recommended as a candidate for “pseudocatalytic” bioscavengers with BChE.
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Affiliation(s)
- Daniel Jun
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove, 500 01, Czech Republic
- Department of Water Resources and Environmental Modeling, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamycka 129, Praha 6—Suchdol, 16521, Czech Republic
- University Hospital Hradec Kralove, Sokolska 581, Hradec Kralove, 50005, Czech Republic
- Authors to whom correspondence should be addressed; E-Mails: (D.J.); (K.K.); Tel.: +420-973-255-193; Fax: +420-495-518-094
| | - Lucie Musilova
- Hospital Pharmacy, University Hospital Hradec Kralove, Sokolska 581, Hradec Kralove, 500 05, Czech Republic; E-Mail:
- Department of Biochemical Sciences, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Heyrovskeho 1203, Hradec Kralove, 50005, Czech Republic
| | - Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove, 50001, Czech Republic; E-Mail:
| | - Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove, 500 01, Czech Republic
- Authors to whom correspondence should be addressed; E-Mails: (D.J.); (K.K.); Tel.: +420-973-255-193; Fax: +420-495-518-094
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13
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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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14
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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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15
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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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16
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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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17
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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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18
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Musilek K, Komloova M, Zavadova V, Holas O, Hrabinova M, Pohanka M, Dohnal V, Nachon F, Dolezal M, Kuca K, Jung YS. Preparation and in vitro screening of symmetrical bispyridinium cholinesterase inhibitors bearing different connecting linkage-initial study for Myasthenia gravis implications. Bioorg Med Chem Lett 2010; 20:1763-6. [PMID: 20138518 DOI: 10.1016/j.bmcl.2010.01.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 01/04/2010] [Accepted: 01/06/2010] [Indexed: 11/25/2022]
Abstract
Reversible inhibitors (e.g., pyridostigmine bromide, neostigmine bromide) of carbamate origin are used in the early treatment of Myasthenia gravis (MG) to block acetylcholinesterase (AChE) native function and conserve efficient amount of acetylcholine for decreasing number of nicotinic receptors. Carbamate inhibitors are known for many undesirable side effects related to the reversible inhibition of AChE. In contrast, this paper describes 20 newly prepared bispyridinium inhibitors of potential concern for MG. Although some compounds from this series have been known before, they were not assayed for cholinesterase inhibition yet. The newly prepared compounds were evaluated in vitro on human erythrocyte AChE and human plasmatic butyrylcholinesterase (BChE). Their inhibitory ability was expressed as IC(50) and compared to standard carbamate drugs. Three compounds presented promising inhibition (in muM range) of both enzymes in vitro similar to the used standards. The novel inhibitors did not present selectivity between AChE and BChE. Two newly prepared compounds were chosen for docking studies and confirmed apparent pi-pi or pi-cationic interactions aside enzyme's catalytic sites. The kinetics assay confirmed non-competitive inhibition of AChE by two best newly prepared compounds.
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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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20
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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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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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22
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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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23
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Krstić DZ, Colović M, Kralj MB, Franko M, Krinulović K, Trebse P, Vasić V. Inhibition of AChE by malathion and some structurally similar compounds. J Enzyme Inhib Med Chem 2008; 23:562-73. [PMID: 18608787 DOI: 10.1080/14756360701632031] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Inhibition of bovine erythrocyte acetylcholinesterase (free and immobilized on controlled pore glass) by separate and simultaneous exposure to malathion and malathion transformation products which are generally formed during storage or through natural or photochemical degradation was investigated. Increasing concentrations of malathion, its oxidation product malaoxon, and its isomerisation product isomalathion inhibited free and immobilized AChE in a concentration-dependent manner. KI, the dissociation constant for the initial reversible enzyme inhibitor-complex, and k3, the first order rate constant for the conversion of the reversible complex into the irreversibly inhibited enzyme, were determined from the progressive development of inhibition produced by reaction of native AChE with malathion, malaoxon and isomalathion. KI values of 1.3 x 10(-4) M(-1), 5.6 x 10(-6) M(-1) and 7.2 x 10(-6)M(-1) were obtained for malathion, malaoxon and isomalathion, respectively. The IC50 values for free/immobilized AChE, (3.7 +/- 0.2) x 10(-4) M/(1.6 +/-0.1) x 10(-4), (2.4 +/- 0.3) x 10(-6)/(3.4 +/- 0.1) x 10(-6)M and (3.2 +/- 0.3) x 10(-6) M/(2.7 +/- 0.2) x 10(-6) M, were obtained from the inhibition curves induced by malathion, malaoxon and isomalathion, respectively. However, the products formed due to photoinduced degradation, phosphorodithioic O,O,S-trimethyl ester and O,O-dimethyl thiophosphate, did not noticeably affect enzymatic activity, while diethyl maleate inhibited AChE activity at concentrations > 10mM. Inhibition of acetylcholinesterase increased with the time of exposure to malathion and its inhibiting by-products within the interval from 0 to 5 minutes. Through simultaneous exposure of the enzyme to malaoxon and isomalathion, an additive effect was achieved for lower concentrations of the inhibitors (in the presence of malaoxon/isomalathion at concentrations 2 x 10(-7) M/2 x 10(-7) M, 2 x 10(-7) M/3 x 10(-7)M and 2 x 10(-7) M/4.5 x 109-7) M), while an antagonistic effect was obtained for all higher concentrations of inhibitors. The presence of a non-inhibitory degradation product (phosphorodithioic O,O,S-trimethyl ester) did not affect the inhibition efficiencies of the malathion by-products, malaoxon and isomalathion.
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Affiliation(s)
- Danijela Z Krstić
- Institute of Chemistry, School of Medicine, University of Belgrade, Belgrade, Serbia
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24
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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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Kuca K, Cabal J, Jun D, Hrabinova M. Potency of Five Structurally Different Acetylcholinesterase Reactivators to Reactivate Human Brain Cholinesterases Inhibited by Cyclosarin. Clin Toxicol (Phila) 2008; 45:512-5. [PMID: 17503257 DOI: 10.1080/15563650701354234] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Acetylcholinesterase (AChE; EC 3.1.1.7) reactivators are used as a part of the antidotal therapy of organophosphorus pesticide and nerve agent intoxications. Cyclosarin is one member of the nerve agent family. In this article, we compared the reactivation potency of five structurally different AChE reactivators (pralidoxime, trimedoxime, methoxime, HS-6, and BI-6) to reactivate cyclosarin-inhibited cholinesterases of human brain. The results demonstrate that the bisquaternary monooxime reactivator BI-6 seems to be the most potent reactivator of cyclosarin-inhibited cholinesterases. Moreover, according to the results, we can describe basic structural requirements, which are necessary for the efficacious reactivation process.
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Affiliation(s)
- Kamil Kuca
- Department of Toxicology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove.,Czech Republic.
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Kuca K, Cabal J, Jun D, Bajgar J, Hrabinova M. Potency of new structurally different oximes to reactivate cyclosarin-inhibited human brain acetylcholinesterases. J Enzyme Inhib Med Chem 2008; 21:663-6. [PMID: 17252938 DOI: 10.1080/14756360600850916] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Antidotes currently used for organophosphorus pesticide and nerve agent intoxications consist of anticholinergics (atropine mainly) and acetylcholinesterase (AChE, EC 3.1.1.7) reactivators called oximes. Owing to the wide-spread of these toxic compounds worldwide, development of antidotes in the case of first aid is needed. To select the most promising AChE reactivators is a very time consuming process, which is necessary before approval of these compounds to be used as human antidotes. Because of ethical reasons, many developing experiments have been conducted on laboratory animals. However, these results often could not be transferred directly to human. Here, we have tested five newly developed AChE reactivators--K027, K033, K048, K074 and K075, which showed promising reactivation activity on rodents, as reactivators of inhibited human brain cholinesterases. For this purpose, cyclosarin was used as member of the nerve agent family. Oxime HI-6 and pralidoxime were used as AChE reactivator standards. Two AChE reactivators, K027 and K033, achieved comparable reactivation potency as HI-6. Moreover, oxime K033 reached its maximal reactivation potency at the lowest concentration which could be attained in humans.
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Affiliation(s)
- Kamil Kuca
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic.
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Hrabinova M, Musilek K, Jun D, Kuca K. New group of xylene linker-containing acetylcholinesterase reactivators as antidotes against the nerve agent cyclosarin. J Enzyme Inhib Med Chem 2008; 21:515-9. [PMID: 17194020 DOI: 10.1080/14756360600741420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Nerve agents such as sarin, cyclosarin and tabun are organophosphorus substances able to inhibit the enzyme acetylcholinesterase (AChE; EC 3.1.1.7). AChE reactivators and anticholinergics are generally used as antidotes in the case of intoxication with these agents. None of the known AChE reactivators is able to reactivate AChE inhibited by all nerve agents used. In this work, reactivation potency of nine newly developed AChE reactivators with an incorporated xylene ring in their structure was measured in vitro. Cyclosarin was chosen as an appropriate member of the nerve agent family. Reactivation potency of the tested AChE reactivators was compared with the gold standard of AChE reactivators--pralidoxime. Two oximes (K107 and K108) surpassed the reactivation potency of pralidoxime. Moreover, from the obtained results it could be deduced that AChE reactivators with a functional oxime group in position-2 are the most potent AChE reactivators in the case of cyclosarin intoxications.
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Affiliation(s)
- Martina Hrabinova
- Department of Toxicology, Faculty of Military Health Sciences, University of Defence, 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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Lorke DE, Hasan MY, Arafat K, Kuca K, Musilek K, Schmitt A, Petroianu GA. In vitro oxime protection of human red blood cell acetylcholinesterase inhibited by diisopropyl-fluorophosphate. J Appl Toxicol 2008; 28:422-9. [PMID: 18344198 DOI: 10.1002/jat.1344] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oximes are enzyme reactivators used in treating poisoning with organophosphorus cholinesterase (AChE) inhibitors. The oxime dose which can be safely administered is limited by the intrinsic toxicity of the substances such as their own AChE-inhibiting tendency. Clinical experience with the available oximes is disappointing. To meet this need, new AChE reactivators of potential clinical utility have been developed. The purpose of the study was to estimate in vitro both the intrinsic toxicity and the extent of possible protection conferred by established (pralidoxime, obidoxime, HI-6, methoxime, trimedoxime) and experimental (K-type) oximes, using diisopropyl-fluoro-phosphate (DFP) as an AChE inhibitor. The IC50 of DFP against human red blood cell AChE was determined ( approximately 120 nm). Measurements were then repeated in the presence of increasing oxime concentrations, leading to an apparent increase in DFP IC50. Calculated IC50 values were plotted against oxime concentrations to obtain an IC50 shift curve. The slope of this shift curve (tan alpha) was used to quantify the magnitude of the protective effect (nm IC50 increase per microm oxime). We show that, in the case of a linear relationship between oxime concentration and IC50, the binding constant K, determined using the Schild equation, equals IC50/DFP/tan alpha. Based on the values of tan alpha and of the binding constant K, some of the new K-oxime reactivators are far superior to pralidoxime (tan alpha = 0.8), obidoxime (1.5), HI-6 (0.8), trimedoxime (2.9) and methoxime (5.9), with K-107 (17), K-108 (20), and K-113 (16) being the outstanding compounds.
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Affiliation(s)
- D E Lorke
- UAE University, Faculty of Medicine and Health Sciences, 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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32
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Musilek K, Holas O, Kuca K, Jun D, Dohnal V, Dolezal M. Synthesis of a novel series of non-symmetrical bispyridinium compounds bearing a xylene linker and evaluation of their reactivation activity against tabun and paraoxon-inhibited acetylcholinesterase. J Enzyme Inhib Med Chem 2007; 22:425-32. [PMID: 17847708 DOI: 10.1080/14756360601164960] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Nine potential non-symmetrical xylene-bridged AChE reactivators were synthesized using modifications of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and the insecticide paraoxon together with nine symmetrical xylene-bridged compounds, was tested in vitro. Seven compounds were promising against paraoxon-inhibited AChE. Two compounds were found to be more potent against tabun-inhibited AChE than obidoxime at a concentration applicable in vivo.
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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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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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Musilek K, Jun D, Cabal J, Kassa J, Gunn-Moore F, Kuca K. Design of a Potent Reactivator of Tabun-Inhibited AcetylcholinesteraseSynthesis and Evaluation of (E)-1-(4-Carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene Dibromide (K203). J Med Chem 2007; 50:5514-8. [DOI: 10.1021/jm070653r] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kamil Musilek
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - Daniel Jun
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - Jiri Cabal
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - Jiri Kassa
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - Frank Gunn-Moore
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - Kamil Kuca
- Department of Toxicology, and Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Prague, Czech Republic, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom
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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, 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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Kuca K, Cabal J, Jun D, Musilek K. In vitro reactivation potency of acetylcholinesterase reactivators--K074 and K075--to reactivate tabun-inhibited human brain cholinesterases. Neurotox Res 2007; 11:101-6. [PMID: 17449453 DOI: 10.1007/bf03033389] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this work, two oximes for the treatment of tabun-inhibited acetylcholinesterase (AChE; EC 3.1.1.7), K074 (1,4-bis(4-hydroxyiminomethylpyridinium)butane dibromide) and K075 ((E)-1,4-bis(4-hydroxyiminomethylpyridinium)but-2-en dibromide), were tested in vitro as reactivators of AChE. Comparison was made with currently used AChE reactivators (pralidoxime, HI-6, methoxime and obidoxime). Human brain homogenate was taken as an appropriate source of the cholinesterases. As resulted, oxime K074 appears to be the most potent reactivator of tabun-inhibited AChE, with reactivation potency comparable to that of obidoxime. A second AChE reactivator, K075, does not attain as great a reactivation potency as K074, although its maximal reactivation (17%) was achieved at relevant concentrations for humans.
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Affiliation(s)
- Kamil Kuca
- Centre of Advanced Studies, and Department of Toxicology, Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic.
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Musílek K, Kuča K, Jun D, Doležal M. In vitro reactivation potency of bispyridinium (E)-but-2-ene linked acetylcholinesterase reactivators against tabun-inhibited acetylcholinesterase. J Appl Biomed 2007. [DOI: 10.32725/jab.2007.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Structure—activity relationships for in vitro oxime reactivation of chlorpyrifos-inhibited acetylcholinesterase. CHEMICAL PAPERS 2007. [DOI: 10.2478/s11696-007-0030-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AbstractOrganophosphorus pesticides parathion, chlorpyrifos, and malathion inhibit the enzyme acetylcholinesterase (AChE; EC 3.1.1.7) via phosphorylation of its active site. AChE reactivators and anticholinergics are compounds used as antidotes in the case of intoxication by these AChE inhibitors. In this work, chlorpyrifos, a representative member of this pesticide family, was used to inhibit the AChE activity of rat brain. The effect of twenty-one structurally different AChE reactivators was tested in vitro and subsequently, the relationship between their chemical structure and biological activity was outlined.
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Musilek K, Holas O, Kuca K, Jun D, Dohnal V, Dolezal M. Synthesis of asymmetrical bispyridinium compounds bearing cyano-moiety and evaluation of their reactivation activity against tabun and paraoxon-inhibited acetylcholinesterase. Bioorg Med Chem Lett 2006; 16:5673-6. [PMID: 16934462 DOI: 10.1016/j.bmcl.2006.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 07/31/2006] [Accepted: 08/01/2006] [Indexed: 10/24/2022]
Abstract
Three asymmetrical AChE reactivators with cyano-moiety and propane linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by nerve agent tabun and insecticide paraoxon was tested in vitro and compared to pralidoxime, HI-6, obidoxime, K027, and K048. According to the results, three compounds seem to be promising against paraoxon-inhibited AChE. Better results were obtained for bisquaternary substances at least with one oxime group in position four. None of tested substances was able to satisfactorily reactivate tabun-inhibited AChE at concentration applicable for in vivo experiments.
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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, 50005 Hradec Kralove, Czech Republic
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Potency of Several Structurally Different Acetylcholinesterase Reactivators to Reactivate House Fly and Bovine Acetylcholinesterases Inhibited by Paraoxon and DFP. B KOREAN CHEM SOC 2006. [DOI: 10.5012/bkcs.2006.27.9.1401] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Račáková V, Jun D, Opletalová V, Kuča K. Reactivation of acetycholinesterase inhibited by the pesticide chlorpyrifos. J Appl Biomed 2006. [DOI: 10.32725/jab.2006.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Oh KA, Yang GY, Jun D, Kuca K, Jung YS. Bis-pyridiumaldoxime reactivators connected with CH2O(CH2)n OCH2 linkers between pyridinium rings and their reactivity against VX. Bioorg Med Chem Lett 2006; 16:4852-5. [PMID: 16828550 DOI: 10.1016/j.bmcl.2006.06.063] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 06/12/2006] [Accepted: 06/17/2006] [Indexed: 10/24/2022]
Abstract
New bis-pyridinium oxime reactivators connected with CH2O(CH2)n OCH2 linkers between two pyridinium rings were designed and synthesized, and their reactivation potency was evaluated for AChE inhibited by organophosphorus VX agent. Among the prepared compounds, 1,2-dimethoxy-ethylene-bis-N,N'-4-pyridiumaldoxime dichloride 5a was the most potent and appeared to be the most promising compound as a potential reactivator for AChE inhibited by organophosphorus VX agent.
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Affiliation(s)
- Kyung-Ae Oh
- Medicinal Science Division, Korea Research Institute of Chemical Technology, PO Box 107, Yusong, Taejon 305-606, Republic of Korea
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