Advances in toxicology and medical treatment of chemical warfare nerve agents

Chemical warfare nerve agents (NAs) are one of the important groups of organophosphorous (OP) compounds that have been used as tactical weapons and for terrorism during recent decades. OP compounds have also been used as petroleum additives and pesticides [1]. Although NAs are strongly similar in chemical structure and biological function to many OP pesticides, fatality potency of NAs is generally higher than the OP pesticides [2].The NAs are traditionally classified into two classes of G and V agents, but also GV compounds (GV:2-dimethylaminoethyl-(dimethylamido)-fluorophosphate) which contained structures of both G and V agent are now exist. The G agents include Tabun (GA; ethyl N, N-dimethylphophoramidocyanidate), Sarin (GB; 2-fluoro-methylphophoryloxypropane), Soman (GD; 3-fluoromethyl-phosphoryloxy-2, 2-dimethyl-butane) and Cyclosarin (GF; fluoro-methylphophoryloxycyclohexane). The important warfare V agents include VE (S-2-diethylaminoethyl O-ethylethylphophonothioate), VM (2-ethoxy-methylphosphoryl sulfanyl-N,N-diethylethanamine), VG (2 diethoxyphosphorylsulfanyl- N,N-diethylethanamine), VR (Russian VX; N,N-diethy-2-methyl-2-methylpropoxy phosphorylsulfanylethanamine) and VX (S-2 diisopropylamino O-ethylmethylphosphonothioate) [3-5]. There are no common names for other G and V agents. VX is the main and oldest agent of V series which has been produced in large quantities [1,5,6]. Recently a new type of NAs has been claimed to develop named "Novichoks" (means “newcomer” in Russia). This has been attracting increasing attention in recent years, particularly among non-governmental organizations (NGOs). It has been claimed that the toxicity of certain “Novichok” agents may exceed that of VX. The action mechanism is also dissimilar to the other NAs and thus conventional antidotes may be ineffective. Though, to date, there is nothing in details on such chemical has ever been declared in the literature [7,8]. NAs are delivered by missiles, bombs, spray and cluster s