Resistance organophosphorus

Newcomb R. D., Campbell P. M., Russell R. J. and Oakeshott J. G. (1997) cDNAcloning, baculovirus-expression and kinetic properties of the esterase, E3, involved in organophosphorus resistance in Lucilia cuprina. Insect Biochem. Mol. Biol. 27, 15— 25. 

Chapman, R.B. and Penman, D.R., Negatively correlated cross-resistance to a synthetic pyrethroid in organophosphorus-resistant Tetranychus urticae, Nature, 281, 298,1979. 

Lewis, J.B. and Sawicki, R.M., Characterization of the resistance mechanisms to diazinon, parathion and diazoxon in the organophosphorus-resistant SKA strain of house flies (Musca domestica L.), Pestic. Biochem. Physiol., 1, 275,1971. 

Pasteur, N. and Georghiou, G.P., Improved filter paper test for detecting and quantifying increased esterase activity in organophosphorus-resistant mosquitoes (Diptera Culicidae), /. Econ. Entomoi, 82, 347,1989. 

Yeoh, C. L., Kuwano, E., and Eto, M., Studies on the mechanisms of organophosphorus resistance in oriental house flies, Musca domestica vivina Macquart (Diptera Muscidae), Appl. EntomoL ZooL, 16, 247,1981. 

At tin, F.l. and Freeker, T. (1984). Cross-resistance spectrum and synergism studies in organophosphorus-resistant strains of Oryztiephilus sttrinamensis (I,.) (C oleoptera Cucujidae) in Australia. J. Rootj. Erilonicr . 77. 1367-[370. 

Family Pesticide Growth in Resistance, of Times Organophosphorus Pesticides (OPPs) ... 

Other chemicals evaluated but not yet adopted commercially include organophosphorus compounds, triphenyltin compounds, quaternary ammonium salts, imidazoles, benzimidazoles, carbamates and the precocene anti-juvenile hormones [517]. Although none of the above has found use as an insect-resist agent, several have been used as antimicrobial agents for textiles. 

The first silicon-organophosphorus betaine with a thiolate center (15a) was synthesized by the reaction of stable silanethione (14) with trimethyl-methylenephosphorane (Scheme 8) and characterized by multinuclear NMR spectroscopy.14 Compound 15a is formed under kinetic control and is transformed, under the thermodynamically controlled conditions, into the silaacenaphthene salt (16). The processes presented in this scheme reflect the competition of the basicity and nucleophilicity of phosphorus ylides. Betaine 15b prepared from less nucleophilic and less basic ylide with phenyl substituents at the phosphorus atom is much less resistant toward retro-decomposition compared to the alkyl analog. Its equilibrium concentration does not exceed 6%. 

Insects have acquired resistance to organochlorine compounds, such as DDT and BHC, developed as agricultural and hygienic insecticides after World War II. This insect resistance was also acquired to subsequent organophosphorus compounds and carbamate insecticides. Photostable pyrethroids have been developed for outdoor use because pyrethroids were found to be effective against these resistant pests. As a matter of course, these pyrethroids are also effective against sanitary pests however, problems associated with safety and chemical residues indoors must be resolved. 

Resistance to insecticides has drawn global attention since the Korean War in 1950 when the mass use of organic synthetic insecticides, such as DDT and BHC, against agricultural pests and sanitary pests became common. Organophosphorus compounds and carbamates were used thereafter, but invited problems of safety concerns and insect resistance. Synthetic pyrethroids were watched with keen interest as alternatives and have become used widely not only for sanitary pests but also agricultural pests. The development of resistance to synthetic pyrethroids is also not a rare phenomenon and has spread all over the world. 

McPhillips JJ, Dar MS. 1967. Resistance to the effect of carbachol on the cardiovascular systemll and on the isolated ileum of rats after subacute administration of an organophosphorus cholinesterase inhibition. J Pharmacol Exp Ther 156 507-513. 

Further, by virtue of their larger livers, the R fish have a greater xenobiotic biotransformation potential. However, the in vivo studies show few consistent differences in metabolism between the two populations. Biotransformation may be a major contributory factor in mosquitofish resistance to other pesticides, for example, organophosphorus and botanical insecticides, since the level of resistance to these chemicals is very low (4 fold or less) 08,20,21). However, biotransformation does not appear to play a major role in organochlorine insecticide resistance. 

Carboxylesterases are well-represented in insects and are sometimes important in the development of resistance to insecticides. Thus, a well-characterized carboxylesterase E4 is responsible for resistance to organophosphorus insecticides in the aphid (Myzuspersicae) [107]. In the California Culex mosquito, the esterase B1 is 500-fold more abundant in organophosphate-resistant than in susceptible insects. The increase of esterase levels is the result of gene amplification, i.e., the resistant animals have an increased number of copies of the structural esterase gene [108],... 

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. 

Insect resistance and environmental pollution due to the repeated application of persistent synthetic chemical insecticides have led to an Increased interest in the discovery of new chemicals with which to control Insect pests. Synthetic insecticides, including chlorinated hydrocarbons, organophosphorus esters, carbamates, and synthetic pyrethroids, will continue to contribute greatly to the increases in the world food production realized over the past few decades. The dollar benefit of these chemicals has been estimated at about 4 per 1 cost (JJ. Nevertheless, the repeated and continuous annual use in the United States of almost 400 million pounds of these chemicals, predominantly in the mass agricultural insecticide market (2), has become problematic. Many key species of insect pests have become resistant to these chemicals, while a number of secondary species now thrive due to the decimation of their natural enemies by these nonspecific neurotoxic insecticides. Additionally, these compounds sometimes persist in the environment as toxic residues, well beyond the time of their Intended use. New chemicals are therefore needed which are not only effective pest... 

The stationary phases coated on the inert supports are similar in the two classes of columns. Liquids of different polarities are chosen for the separation of non-polar or polar compounds a relatively small number of solvents, chemically inert and heat resistant, are sufficient for most residue analyses. The most commonly used for organophosphorus compounds vary from low-polarity hydrocarbons, methylsilicones, phenylsilicones, phenylmethylsilicones or carboranesiloxanes 165 168 175 178 180 182 184 192,195,197,198,... 

Another important problem is the development of insects resistant to insecticides. This often arises as a result of increased levels of carboxylesterases which hydrolyze both organophosphates and car-baryl.h/1 A mutation that changed a single active site glycine to aspartate in a carboxylesterase of a blowfly changed the esterase to an organophosphorus hydrolase which protected the fly against insecticides.)... 

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