Warfare agent

Brief notes are added on phosphorofluoridates even though their destruction by microbial activity— though clearly possible—is limited by their toxicity to the requisite microorganisms. One of the motivations for their inclusion is the fact that the hydrolytic enzyme(s) responsible for defluorination—organophosphorus acid anhydrase (OPA)—is widespread, and is found in a number of bacteria (Landis and DeFrank 1990). The microbial hydrolysis of organophosphorus pesticides and cholinesterase inhibitors is accomplished by several distinct enzymes, which are collectively termed organophosphorus acid anhydrases (OPAs). These have been reviewed (DeFrank 1991), so that only a few additional comments are necessary. 

All these observations underscore the potential for application of appropriate OPAs to the destruction of organophosphorus compounds with anticholinesterase activity (Cheng and Calomiris 1996). However, since, hydrolysis results in release of fluoride, the possibility of its subsequent incorporation into organic substrates to produce fluoroacetate and 4-fluorothreonine (Reid et al. 1995) may be worth consideration. 

Achnich A, E Fernandes, J-M Bollag, H-J Knackmuss, H Lenke (1999) Covalent binding of reduced metabolites of [ NjJTNT to soil organic matter during a bioremediation process analyzed by NMR spectroscopy. Environ Sci Technol 33 4448-4456. 

Dayman P, GV Radkar (1997) Transformation and tolerance of TNT (2,4,6-trinitrotoluene) by fungi. Int Bio-det Biorem 39 45-53. 

Binks PR, CE French, S Nicklin, NC Bruce (1996) Degradation of pentaerythritol tetranitrate by Enterobacter cloacae PB2. Appl Environ Microbiol 62 1214-1219. 

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Agents, chemical warfare Agent VX [50782-69-9] Age-resistant elastomers AgeRiteDPPD [74-31-7] AgeRite White AgeRite Write [93-46-9] Ageusia Agglomeration... 

Chemical warfare Chemical warfare agent Chemigum... 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

Kientz Ch.E. Cliromatography and mass spectrometry of chemical warfare agents, toxins and related compounds state of the art and future prospects // J.Cliromatogr. A. 814 (1998) 1. 

Kampfstofl, m. war material, esp. a chemical warfare agent, -beschuss, m. chemical-shell fire, -bombe, /. chemical bomb, gas bomb, -gehalt, m. (Mil.) gas concentration, -schwaden, m. (Mil.) chemical fumes, gas fumes, -sperre, /. (Mil.) chemical obstacle, -verwendung, /. (Mil.) use of chemical warfare agents, -zerstauber, m. (Mil.) chemical spray apparatus. 

Discovered in the late 1930s in Germany as improved poisonous insecticides, organophosphorus ChEIs were developed as chemical warfare agents (e.g. sarin, soman, and tabun) and were more recently employed in the 1995 terrorist attack in the Tokyo subway system [5]. 

Cholinesterase inhibitor (anti-cholinesterase, ChEI) is a chemical that prevents cholinesterases (ChEs) from breaking down. ACh, which consequently increases the level and duration of action of this neurotransmitter. ChEIs such as organophosphates (esters of phosphoric acid) and carbamates (esters of carbamic acid) - serve as insecticides, pesticides, warfare agents and drugs. 

As explained in Chapter 1, the toxicity of natural xenobiotics has exerted a selection pressure upon living organisms since very early in evolutionary history. There is abundant evidence of compounds produced by plants and animals that are toxic to species other than their own and which are nsed as chemical warfare agents (Chapter 1). Also, as we have seen, wild animals can develop resistance mechanisms to the toxic componnds prodnced by plants. In Anstralia, for example, some marsupials have developed resistance to natnrally occnrring toxins produced by the plants upon which they feed (see Chapter 1, Section 1.2.2). 

Chemical warfare agents, such as soman and sarin, sometimes termed nerve gases, are powerful anticholinesterases, which bear some resemblance in structure and properties, to the OP insecticides. A major difference from most insecticides is their high volatility. These agents were possessed by the major powers during World War II, althongh they were never employed in warfare. 

Marrs, T.C., Maynard, R.L., and Sidell, F.R. (2007). Chemical Warfare Agents—Toxicology and Treatment (2nd Edition). Chichester, U.K. John Wiley and Sons. 

Maynard, R.L. and Beswick, RW, (1992). Organophosphorous compounds as chemical warfare agents. In B. BaUantyne and T.C. Marrs (Eds.) Clinical and Experimental Toxicology of Organophosphates and Carbamates 373-385. 

Other interesting examples of proteases that exhibit promiscuous behavior are proline dipeptidase from Alteromonas sp. JD6.5, whose original activity is to cleave a dipeptide bond with a prolyl residue at the carboxy terminus [121, 122] and aminopeptidase P (AMPP) from E. coli, which is a prohne-specific peptidase that catalyzes the hydrolysis of N-terminal peptide bonds containing a proline residue [123, 124]. Both enzymes exhibit phosphotriesterase activity. This means that they are capable of catalyzing the reaction that does not exist in nature. It is of particular importance, since they can hydrolyze unnatural substrates - triesters of phosphoric acid and diesters of phosphonic acids - such as organophosphorus pesticides or organophosphoms warfare agents (Scheme 5.25) [125]. 

All the enzymes discussed above belong to the class of dimetalloenzymes. In this context, it should be mentioned that serine-type hydrolases are irreversibly inhibited by organophosphorus esters, among them highly toxic chemical warfare agents. However, in some cases, for example of human butyrylcholi-noesterase, the inhibited enzyme could be reactivated by proper mutations." Moreover, such mutahons were found to confer phosphotriesterase activity in this... 

Aryl phosphates and thiophosphates, and alkyl dithiophosphates are important agrochemicals, while phosphorofluoridates have been prepared as chemical warfare agents. Concern over the persistence and the biodegradability of organophosphate and organophosphorothioates, which are nsed as agrochemicals, has stimnlated stndies into their degradation. Considerable attention has been... 

Soluble in organic solvents and oils insoluble in water and dilute mineral acids. Because of its good miscibility with other chemical warfare agents, L-1 is suitable for the preparation of tactical mixtures. 

Sesquimustard has not been typically listed as a chemical warfare agent until it was listed in the CWC Schedule I. It is one of the most powerful vesicants currently known and is highly toxic by inhalation. 

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