V-agents were synthesized after World War II in the United Kingdom. The V was derived from the word victory, the share of allied forces from World

War II. The V agents are sulfur containing organophosphate compounds. Among these compounds VE (S-2-diethylamino ethyl O-ethylethylphophonothioate), VG (2 diethoxyphosphorylsulfanyl- N,N-diethylethanamine), VM (2-ethoxy-methylphosphoryl sulfanyl-N,N-diethylethanamine), VR (Russian VX; N,N-diethy-2-methyl-2-methylpropoxy Inhibitors,research,lifescience,medical phosphoryl sulfanylethanamine) and VX (S-2 diisopropylamino O-ethylmethylphosphonothioate) are important as warfare nerve agents. The V-agents are more toxic than the G-agents.5,6 Nerve agent tabun was used in the battlefield for the first time in 1984 by Iraqi army to achieve victory against Iran. From 1983 to 1988, Iraq used sulfur mustard and nerve agents such as sarin and tabun against Iranian combatants, and later against Inhibitors,research,lifescience,medical the civilians. Nerve agents were also used by Iraq in 1988 against Iraqi Kurdish civilians during Halabjah massacre. It was estimated that 45,000 to 100,000 individuals were poisoned by chemical weapons during the Iraq-Iran war. The poisoning, which was associated with high mortalities, was mostly caused by the nerve agents.7,8 Matsomoto (June 27, 1994) and Tokyo

subway (March 20, 1995) attacks in Japan by sarin are Inhibitors,research,lifescience,medical other well-known OP nerve agent incidents with 12 deaths and more than five thousands intoxicated people.9-11 Despite the establishment of organization for prohibition of chemical weapons (OPCW), OP nerve agents are still threat to the human population. In addition, wide use of OP pesticides in most developing countries including Iran has induced health problems. Hence, it is quite logical that

health professionals should increase their knowledge Inhibitors,research,lifescience,medical about all aspects of OPs, particularly on recent advances in the treatment of pesticides and nerve agent poisonings. Chemistry and Toxicology Organophosphorous compounds including organophosphates are chemically derived from phosphoric, phosphonic, phosphinic or thiophosphoric acids. Organophosphates are usually Inhibitors,research,lifescience,medical esters, amides, or thiol derivatives of phosphoric, phosphonic, or phosphinic acids. The general formula Megestrol Acetate of organophosphates is as follows: R1 and R2 are alkyl-, alkoxy-, alkylthio- or amido groups. X is the acyl residue. Organophosphorous pesticides vary in chemical check details structures and toxicities. The main groups are phosphate, phosphorothioate, O-alkyl phosphorothioate and phosphorodithioate. A phosphorthioate compound such as parathion is much more toxic than a phosphorodithioate compound like Malathion. Apart from the OP pesticides and chemical warfare nerve agents, very few OP compounds such as glyphosate and merphos were used as herbicides. Organophosphorous herbicides differ from the OP pesticides structurally and their AChE–inhibiting power is much less than the other OPs.12 Although the term “nerve gas” is frequently used, all the nerve agents are liquids at standard temperature and pressure.