Pesticides and nerve

Y. Lin, F. Lu, and J. Wang, Disposable carbon nanotube modified screen-printed biosensor for ampero-metric detection of organophosphorus pesticides and nerve agents. Electroanalysis 16, 145-149 (2004). 

The exaggerated or unwanted pharmacological responses are the most common toxic effects of drugs observed clinically, as opposed to direct toxic effects on tissues. However, this type of response may also be observed with other compounds such as the toxic cholinesterase inhibitors used as pesticides and nerve gases. 

This group of compounds is used as pesticides and nerve gases. The structure and therefore metabolism and potency varies. However, they all act in a similar manner. There are two toxic effects, cholinesterase inhibition and delayed neuropathy, but all OPs do not necessarily cause both. The cholinesterase inhibition results from the similarity between the organophosphorus compound and acetylcholine. The organophosphorus compound therefore acts as a pseudosubstrate but blocks the enzyme, in some cases, permanently. This is because the... 

John H, Worek F, Thiermann H (2008) LC-MS based procedures for monitoring of toxic organophosphorus compounds and the verification of pesticide and nerve agent poisoning. Anal Bioanal Chem 391 97-116... 

The search for a noncorrosive decontamination of sensitive material and skin after exposure by toxic chemicals like pesticides and nerve agents, is an important but challenging task. Therefore, the development of cost-effective cleanup... 

In addition to being found in the nervous system, acetylcholinesterase also occurs in the blood where it is bound to the surface of red blood cells (termed RBC-ChE or RBC-AChE). RBC-AChE activity, as well as the activity of a second type of cholinesterase found in blood plasma (butyrylchoUnesterase, or plasma cholinesterase) have been used to monitor exposure to organophosphate compounds (pesticides and nerve agents). Both RBC-AChE and plasma-ChE activity have been used as bioindicators of potential toxic effects. There is some evidence that RBC-AChE is as sensitive as brain ChE to the effects of nerve agents. Grob and Harvey (1958) reported that the in vitro concentrations producing 50% depression of brain-ChE and RBC-AChE activity were the same in the case of GA (1.5 x 10 mol/L),... 

Chemicals come in all shapes and sizes and derive from a variety of sources. While to many people the words chemical and indeed poison are synonymous with man-made things such as dioxin, organo-phosphates, pesticides, and nerve gas, there are many, many other chemicals that occur naturally These may be produced by plants, for example belladonna in deadly nightshade, and ricin in the castor bean, or bacteria, for example botulinum toxin. Various animals such as snakes and spiders produce toxic venoms, and some poisons occur naturally in the ground, like asbestos, cadmium, and lead. 

Liu, G., Lin, Y. (2006). Biosensor based on self-assembling acetylcholinesterase on carbon nanotubes for flow injection/ amperometric detection of organophosphate pesticides and nerve agents. Anal. Chem. 78 835 3. 

These enzymes are promising for destruction of chemical weapons stockpiles, soil remediation, decontamination of materials, protective equipment, and water polluted by pesticides and nerve agents (Russel et al, 2003). In particular, phosphorothiolates such as VX are relatively resistant to PTE. Thus, oxidative cleavage of the P-S bond could be achieved by oxidases like laccases. These enzymes could be used in association with other OP-degrading enzymes for skin decontamination or in topical skin protection formulations. Though no work has been performed on combined action of oxidases and hydrolases, oxidation of P-bonded alkyl/aryl chains by oxidases is expected to alter enantio-selectivity of PTE for parent OPs, and therefore to improve the efficiency of catalytic bioscavengers. 

It has been shown that the organophosphate ester tributylphosphate is very effectively solubilized by a microemulsion system incorporating CTAB and sulfolane as the emulsifier. The single-phase region in this system is similar to that obtained with CTAB and butanol as the emulsifier reported by Mackay (6). Thus it is expected that sulfone-containing microemulsions will solubilize other organophosphates and phosphonates such as pesticides and nerve agents. 

OPs, both pesticides and nerve agents, lose their leaving groups when they react with... 

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