Toxicity organophosphorus compounds

Dettbarn WD and Gupta RC (1989) Role of esterases as false targets in organophosphorus compounds toxicity. In Reiner E, Aldridge WN, and Hoskin FCG (eds.)... 

ORGANOPHOSPHORUS COMPOUND, toxic. nammUc. n.o.s. tWheii liiliaiaiK)n Haiard" b mi a package or shipping paper.) lOOO 1.2 3.3 1500 3.5 5.9... 

TABLES QSAR equations for LC50 to guppy of 10 organophosphorus compounds, toxicity data from TABLE 3 . 

Many organophosphorus compounds are highly toxic and frequently lethal. They have been actively developed for herbicides, pesticides and more sinister purposes such as nerve gases which disorient, harass, paralyse or kill. ... 

In spite of their toxicity, alkyl phosphites have been used extensively as lubricant additives, corrosion inhibitors, and antioxidants. In addition to their use as intermediates in synthesis, organophosphorus compounds are useful for separating heavy metals by solvent extraction. Several insecticides that were formerly in widespread use are derivatives of organic phosphates. Two such compounds are malathion and parathion. 

As a result of the hazards in using compounds such as these, the use of parathion has been banned in the United States since 1991. Another of the toxic organophosphorus compounds is sarin, a nerve gas that was produced for military use ... 

Although these organic phosphate derivatives are highly toxic and have been used in ways to exploit that property, many organophosphorus compounds have significant utility in the chemical industry. 

Epstein, J., K.E. Levy, and H.O. Michel. "Production of Toxic Organophosphorus Compounds," United States Patent 3903210, September 2,1975. 

Shulga V., Delayed neuro-endocrine toxicity indused by organophosphorus compounds-natural consequence of poisonous substances application for terrorist purpose , In Medical Aspects of Chemical and Biological Terrorism -Chemical Terrorism and Tramautism, Alexander Monov and Christophor Dishovsky, eds, Publishing House of the Union of Scientists in Bulgaria, 2005 ( in press). 

The toxicity of the P-halidc anhydrides, like that of phosphoroxychloride (POCl3) and of other organophosphorus compounds discussed earlier in this section, is due to their high efficiency as irreversible inactivators of acetylcholinesterase [157]. The main target organs for the lethal effects of these chemical weapons are the brain and diaphragm. As for the detoxification of the P-halide anhydrides, it can occur by a number of biochemical mechanisms, namely chemical hydrolysis, enzymatic hydrolysis, and binding to hydrolases such as carboxylesterases, cholinesterases, and albumin [68][158][159]. 

Irreversible inhibition in an organism usually results in a toxic effect. Examples of this type of inhibitor are the organophosphorus compounds that interfere with acetylcholinesterase (see Box 7.26). The organophosphorus derivative reacts with the enzyme in the normal way, but the phosphory-lated intermediate produced is resistant to normal hydrolysis and is not released from the enzyme. 

The enzyme becomes inactivated, and a toxic level of acetylcholine builds up. Organophosphorus compounds provide a range of insecticides and nerve gases. 

Selected entries from Methods in Enzymology [vol, page(s)] Types of organophosphorus inhibitors, 11,686-688 toxicity hazards, 11,688 purity and analysis, 11,688 solutions of organophosphorus compounds, 11,689 estimation of specific radioactivity of organophosphorus compounds, 11,689-690 method for estimating phosphorus content, 11,691 reactions with enzymes, 11,691 -701 [rate constants, 11,692 phosphorylation of chymotrypsin, 11, 694-696 identification of phosphoryl and phosphonyl peptides,... 

Carbamates are sold at a lesser volume than are organophosphorus compounds. The first carbamate (urethane) insecticides were developed in the late 1940s at Geigy Chemical Co. in Switzerland. Research on carbamates was inspired by the known toxicity of the alkaloid physostigmine, which occurs naturally in a West African bean. 

Other important series of chemical warfare (CW) agents include fluoride-containing organophosphorus compounds that possess extremely high toxicity (Scheme 6). 

Two factors contribute to the safety of oximes in the treatment of acute poisoning by organophosphorus compounds recommended doses are small, compared with doses likely to cause even mild toxic effects in normal subjects and adverse effects of oximes are reduced in the presence of poisoning by an organophosphorus compound. 

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