Organophosphorus pesticides structure

B. Structures of Common Organophosphorus Pesticides and Abundant Ions... 

Model compounds (simulants) are often used to estimate the reactivity of organophosphorus pesticides and warfare agents toward potential remediation technologies because of their availability and ease of handling [5-18]. The structures of select organophosphorus pesticides, chemical warfare agents, and model compounds (simulants) are presented in Fig. 1. 

Organophosphorus compounds are used widely as pesticides and some also have other industrial uses. These diagrams shows the generic chemical structures for the major classes of organophosphorus pesticides ... 

Eldred DV, Jurs PC. Prediction of acute mammalian toxicity of organophosphorus pesticide compounds from molecular structure. SAR QSAR Environ Res 1999 10 75-99. 

Sanchez-Martin, M.j. and Sanchez-Camizano, M. (1991) Relationship between the structure of organophosphorus pesticides and adsorption by soil components. Soil Science 1 52, 283-288. 

Organophosphorus pesticides have been the insecticides most commonly used by professional pest control bodies and homeowners for the past three decades (Jeannot and Dagnac 2006). Nevertheless, the decision of the US Environmental Protection Agency (EPA) to phase out certain uses of the organophosphate insecticides because of their potentially toxic effects to humans has led to their gradual replacement by other pesticides. Among them, synthetic pyrethroids have been manufactured since 1950 s based upon the structure of natural pyrethrins, which are chemicals with active insecticidal properties in the pyrethrum extract (a mixture of chemicals found in certain chrysanthemum flowers). Pyrethrins are very unstable in the environment, due to oxidation and UV-radiation. 

Musilek, K., Dolezal, M., Gunn-Moore, R, et al., 2011a. Design/ evaluation and structure-activity relationship studies of the AChE reactivators against organophosphorus pesticides. Med. Res. Rev. 31,548-575. 

On a different setup, Du et al. [31] cast sol-gel silica/gold nanoparticle nanocomposite films on a glassy carbon electrode, which was then impregnated with an acetylcholinesterase (AChE) enzyme (Figure 46.10). The construct was used as a biosensor for organophosphorus pesticide detection. In this system, gold nanoparticles not only offered a biocompatible microenvironment to retain the activity of adsorbed enzyme molecules but also acted as a wire to enhance the direct electron transfer rate between the enzyme active centers and the electrode surface, which otherwise would be blocked by the thick protein shell of the enzyme chemical structure. 

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... 

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