Insecticides used with activated

Dinitrophenol is a member of the aromatic family of pesticides, many of which exhibit insecticide and fungicide activity. DNP is considered to be highly toxic to humans, with a lethal oral dose of 14 to 43mg/kg. Environmental exposure to DNP occurs primarily from pesticide runoff to water. DNP is used as a pesticide, wood preservative, and in the manufacture of dyes. DNP is an uncoupler, or has the ability to separate the flow of electrons and the pumping of ions for ATP synthesis. This means that the energy from electron transfer cannot be used for ATP synthesis [75,77]. The mechanism of action of DNP is believed to inhibit the formation of ATP by uncoupling oxidative phosphorylation. 

Figure 7 shows the course of development of various synthetic pyrethroids developed by retaining chrysanthemic acid as the acid moiety and modifying the alcohol moiety. Numerous useful compounds with favorable characteristics have been derived from the structural modification of natural cinerin I (7). These underlined compounds have been put into practical use as active ingredients, mainly for household insecticides. 

The avermectins, a family of compounds with potent anthelmintic, insecticidal and acaricidal activity, have vividly demonstrated that fermentation products can have entirely unanticipated activities. Besides their utility in animals, they show great promise for the control of insect pests of plants. Although antibiotics have found only a limited role in the control of plant diseases, the desire to find environmentally acceptable alternatives to the chemicals currently used has prompted new research efforts to discover fermentation products for use as pesticides. 

The 0,0-diesters of dithiophosphoric adds, (RO)2P(S)SH, were first reported in 1908.120 Chemical interest in these compounds is threefold (a) their coordination with transition metal ions (b) their use as analytical reagents (c) the biological activity of both the ligands and their metal complexes. They have been used for the vulcanization of rubber121122 and as insecticides the latter activity is related to their enzyme-inhibition ability.123... 

In the indoor environment, many types of products such as crystals, sprays and liquids are applied for active and preventative protection of insects. Insect sprays are particularly popular because they are easy to handle and can be combined with air fresheners. Commonly, the amount of active agents in these products is well below 2%. For example, a commercially available insecticide for indoor use may contain 0.25% tetramethrin, 0.05% D-phenothrin and 1% of the synergist pipero-nyl butoxide. Pyrethroids are also used as active agents in liquid products against furniture beetle. In addition, materials containing natural fibers are often equipped with synthetic pyrethroids as a precaution. Apart from the active ingredients, volatile components such as acetone, aliphatic hydrocarbons, cycloalkanes, branched alkanes C3-benzenes and dipropylene glycol monomethyl ether are usually present in insecticides. 

While the lichen compounds were not as effective as Isotox , a known insecticide used as a positive control, in causing high mortality rates, the insecticidal activity could be further exploited synthetically with other active... 

Theoretically, suxamethonium will be potentiated after administration of metrifonate and, in view of its ability to suppress enzyme activity, metrifonate should be used with great caution in areas where organophosphorus insecticides are used, since they have a similar effect. 

Tetrachlorvinphos is an insecticide/acaricide with contact and stomach poison activity tor control of houseflies, poultry lice, mites (animal), ticks, etc. It is also used as larvicide for animal feed. Its oral LD50 in rats is >2000 mg/kg. 

In order to illustrate the variety of active ingredients used with PBO over a lengthy period, the Australian market leader, Rcckitt Colman s Mortein , is used as an example. Mortein was first established around 880 as a powdered insecticide. It was extended to a liquid in 1928 and to an aerosol in 1953 (Edwarn s, 1982). The Mortem red can (Pressure Pak /Fust Knockdown) has always been the flagship insecticide for this brand. It has contained PBO in a variety of combinations for over 30 years, Examples are shown in Table 17.2. 

Certain neurotoxicants act by directly influencing the electrical activity of the insect nerve membrane through a specific action at ion-selective channels. These phenomena can be studied using many of the neurobiochemical techniques that have successfully been applied to vertebrate nervous systems. In this study we use the technique of insect synaptosomes in superfusion to examine the interaction of a range of insecticidal agents with ion channels in the nerve terminal by monitoring effects on transmitter release. 

It is clear that the insecticide of interest must be used to assay for this type of resistance since 1-naphthyl acetate, a general substrate used to stain for many hydrolases, did not detect malathion carboxylester hydrolase (assayed as the hydrolysis of [14C]-malathion) in starch gel electrophoresis of Culex tarsalis (23). Similarly, trans-permethrin hydrolyzing activity of soybean looper was resolved from 1-naphthyl acetate hydrolyzing activity by polyacrylamide gel electrophoresis (28). Malathion carboxylester hydrolases were not correlated with activity toward 1-naphthyl acetate in Drosophila, Anopheles, and Indianmeal moth (25.29.30). 

---