Resistance pesticide design

Velsicol Chemical LLC, formerly Velsicol Chemical Corporation, designs, manufactures, markets and distributes high performance specialty chemicals and industrial intermediates, primarily based on benzoic acid and the organic compound cyclopentadiene. Its products include chlorendic anhydride and hexachlorocyclopentadiene (HEX). Chlorendic anhydride is corrosion resistant, fire resistant and has high UV stability, and is used in the synthesis of flame retardant polymers such as polyurethanes, unsaturated polyester and epoxy resins. HEX, a reactive intermediate used in the manufacture of agricultural pesticides in the production of flame retardants for the wire and cable industry and in the preparation of chlorendic anhydride. The company s products are produced primarily at a plant in Memphis, Tennessee Velsicol also maintains the Memphis Environmental Center (MEC), which focuses on managing legacy environmental liabilities. The firm is owned by Arsenal Capital Partners, a private equity firm. 

Although pesticides are designed to be toxic, they are designed to be selectively toxic to weeds or insects. As with any chemical, dosage is crucial, and pesticides will inevitably be poisonous to humans if they are exposed to sufficiently large quantities. If used correctly, the majority of modern pesticides are relatively safe. It is when they are misused that they cause toxic effects in animals or humans. The problems associated with DDT are perhaps the prime illustration of this principle. Thus chemicals are not equally toxic to all living things some species are very sensitive, while others are very resistant. 

Pharmaca designed to be resistant to metabolic and especially oxidative attack could be potential persistent environmental pollutants. Since, however, the biological degrading capacity of the water and soil microflora is highly differentiated, compounds stable enough to avoid biotoxification in mammals and other animals may still be sufficiently vulnerable to microbiological attack. Moreover, in the case of therapeutics, food additives and selective, e.g. pheromone-derived pesticides only relatively small quantities of substance are involved. 

As information on the molecular architecture and mechanisms of pesticide sites of action becomes more generally available and the nature and effect of mutations on their sensitivity to pesticides is defined, it should become possible in some cases to design agents that specifically interfere with the altered site of the resistant forms. The same line of reasoning suggests that the design of specific and selective synergists to block individual metabolic resistance mechanisms may eventually be possible. 

Originally, it was thought that these compounds could provide the structural basis for the design of pesticides because it is unlikely that insects would develop resistance to their own or closely related hormones [120]. However, this has proven not to be the case. Most insects possess enzymes such as mixed function oxidases and esterases in their alimentary tract and haemolymph which are, among other functions, important for the metabolism of plant toxins [121, 122]. For example, insects which have developed resistance to insecticides may also show resistance to JH... 

The most successful, in terms of application, has been herbicide resistance, where reduced utilization of herbicides has been claimed. Resistance against diseases (pests) has been one of the priorities in designing genetically modified (GM) plants. This also implies a decrease in the dependence on chemical pesticides. Genetic modification has been shown to provide an additional and less time-consuming tool, and to be a useful means of creating novel resistance, compared to classic breeding. 

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