Sarin structure

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. 

While nerve agents vary in molecular structure, they all exert the same physiological effect on the body an increase in acetylcholine throughout the body caused by interference with a vital enzyme known as cholinesterase. The four primary nerve agents are tabun, sarin, soman, and VX. 

Figure 1 Structures of chemical warfare agents (sarin and soman), simulants (dimethyl methylphosphonate and diisoproyl fluorophosphate), and pesticides (paratliion and diazinon).

Fig. 13.5 The optimized structure of Sarin adsorbed on the octahedral surface of dickite obtained using the ONIOM(B3LYP/6-31G(d,p) PM3) method...

Fig. 13.7 The optimized structure of Sarin- and Soman-[A10(OH)3]2 systems obtained at the B3LYP/6-31G(d) level of theory...

Also the reaction pathways of Sarin decomposition catalyzed by selected forms of MgO were investigated [38]. In the case of the decomposition on the nonhydroxylated MgO surface, the removal of fluorine from Sarin was modeled. Fluorine was transferred from Sarin into binding distance with the Mg atom of the MgO surface (Fig. 13.9). It was revealed that such a structure provides a reliable model for the reaction mechanism. A two-step reaction mechanism was assumed. In the first step, Sarin creates a stable adsorbed complex with MgO through three chemical bonds with the MgO surface (the Al-GB model). It is expected that the transfer of the fluorine atom to the surface of MgO is accompanied by a change in the conformation of Sarin. In the second step, the bond between P and F is broken (the Al(t)-GB model) the fluorine atom is transferred to the Mg atom of the surface and the remaining part of Sarin adopts the most energetically favorable conformation (the Al(f)-GB model). 

Application of in vitro test methods have become advantageous in specific cases, such as structurally defined compounds and delayed neuropathy, since target cell data and biochemical processes associated in delayed neuropathy are known. Microscopic studies reveal that cases of OPIDN have degeneration of axons followed by demyelination of the nervous system.25,26 Epidemiologic studies have indicated mild impairment of the brainstem, spinal cord, and peripheral nerve functions in Gulf War veterans.27 Such studies are consistent with the spectrum of OPIDN syndrome. The main nerve agents have been shown to inhibit NTE in vitro as well as in vivo. Sarin has been shown to produce delayed neurotoxicity when administered at higher doses in protected hens.25-27... 

Their use has since been confirmed in the Iraq-Iran conflict, against the Kurdish population in Iraq, and by terrorists in Japan. They can be divided into three structural classes (Figure 9) the alkyl methylphosphonofluoridates, usually referred to as G agents, for example, sarin (GB), soman (GD), cyclohexylsarin (GF) the V agents, VX (U.S.) and R-33 (Russia) and tabun (GA) (40). 

Kaczmarek A, Gorb L, Sadlej AJ, Leszczynski J (2004) Sarin and Soman Structure and Properties, Struct Chem 15 517-525... 

The use of parathion has resulted in many accidental deaths because of its extreme toxicity. In fact, its use in the United States has been prohibited since 1991, but it is still used in other parts of the world. Sarin is a nerve gas that has been produced for military use, and it has the structure... 

Cohen, E.M., P.J. Christen, and E. Mobach. 1971. The Inactivation of Oximes of Sarin and Soman in Plasma from Various Species. I. The Influence of Diacetylmonoxime on the Hydrolysis of Sarin. Pp. 113-131 in Proceedings of the Koninklijke Nederlandse Akademie Van Wetenschappen, Series C, Biological and Medical Sciences, Vol. 74. J.A. Cohen Memorial issue. Amsterdam North-Holland. Davies, D.R., P. Holland, and M.J. Rumens. 1960. The relationship between the chemical structure and neurotoxicity of alkyl organophosphorus compounds. Br. J. Pharmacol. 15 271-278... 

Yamasue, H., Abe, O., Kasai, K., Suga, M., Iwanami, A., Yamada, H., Tochigi, M., Ohtani, T., Rogers, M.A., Sasaki, T., Aoki, S., Kato, T., Kato, N. (2007). Human brain structural change related to acute single exposure to sarin. Ann. Neurol. 61 37-46. 

The only published study of the brain structural effects of nerve agent exposure in a human population focused on longterm changes induced in victims of the 1995 Tokyo subway sarin attack (Yamasue et al, 2007). In this event, which resulted in 12 deaths, approximately 5,500 victims were exposed to sarin, and essentially all patients exhibited typical symptoms of acute intoxication (Lee, 2003 Ohbu et al. 

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