Piperonyl butoxide PBO

Insect strains resistant Cypermethrin Monooxygenase Piperonyl butoxide (PBO) <200... 

Experiments in this study, done exclusively with midge larvae, include 1) 24-hr toxicity data for representative insecticides, with and without synergists 2) in vivo absorptive uptake and metabolic studies of aldrin and dieldrin, with and without piperonyl butoxide (PBO) 3) body depuration rate (loss to water) for dieldrin 4) determination of optimal in vitro... 

Chemicals. Insecticides, at least 95% pure, were prepared as acetone solutions p-p DDT, lindane, parathion, paraoxon, malathion, malaoxon, propoxur, carbaryl, LandrinR, aminocarb, mexacarbate, allethrin (90%), piperonyl butoxide (PBO) and sesamex. Aldrin was 98.5% and dieldrin was 99+% pure. 

Reactive metabolites of xenobiotics may differ in reactivity, and therefore have varying impact on enzymatic activities in terms of proximity to their origin. For example, some intermediates are highly reactive and directly inhibit the enzyme that leads to their formation. These substances are commonly referred to as suicide inhibitors, for obvious reasons. Some suicide inhibitors, such as piperonyl butoxide (PBO), a pesticide synergist) are common inhibitors of certain CYP isozymes. PBO amplifies the toxicity of certain insecticides by inhibiting the insect s CYP enzymes that are involved in its degradation. It is metabolized to a highly reactive carbene, which forms an inhibitor complex with the heme iron of CYP, as shown in Scheme 3.6. 

Scheme 3.6 Piperonyl butoxide (PBO), a pesticide synergist, and PBO suicide inhibition of CYP. Modified from [49].

Examples of these include sesamin and sesamolin, both active principles of sesame oil, and piperonyl butoxide (PBO) and sesamex, both synthetic products. Although initially developed for use with pyrethrins, they have since been observed to synergize some, but not all, carbamates, organophosphates, pyrethroids, and organochlorines. In addition to the MDP compounds, another type of synergist called MGK 264 was developed to synergize the toxicity of pyrethroids and rotenone. The structure of piperonyl butoxide and MGK 264 are as follows ... 

Piperonyl butoxide (PBO) was patented by Herman V/achs (1949) in the USA, although early production occurred from 1946 onwards, PBO is now manufactured as a speciality chemical in five principal sites using essentially the same process and input raw materials as described by the inventor. Although sathole, which provides over half the weight of the PRO molecule, has been synthesized, no cost-effective process is known which can compete with natural sources, e,g. sassafras oil. 

Selim. S. (1995). Isolation and Identification of Major Degradates of Piperonyl Butoxide (PBO) Following Aqueous Photolysis. Unpublished report no. 95-0396.btc. Biological Test Centre. 2525 McGaw Avenue, PO Box 19791, Irvine, CA 92713-979J, USA. Undertaken for the PBO Task Force, Washington DC, USA. 

The purpose of this chapter is to describe the fate of piperonyl butoxide (PBO) in both laboratory and food-producing animals and to show how understanding... 

Piperonyl butoxide (PBO) in combination wiih pyre thrum and pyrethroids is used to control insect pests on a wide variety of food crops. Defining the nature and magnitude of the residues in crops resulting from such uses is an important part of the evaluation of the safety of the product to humans and to the environment. 

Piperonyl butoxide (PBO) is a very important material for (he formulator of household in seel it ides. It has stood the lest ol time and is widely used in a variety of formulations in most parts of the world. 

PhololytLc degradation 81-104 analytical procedures 83-5 Phutotoxius 308 Phthirus pubis 293 Physical characteristics 56 Physical properties 76 Pinwesinol and derivatives i PLperoityl alcohol 115 Piperonyl butoxide (PBO> background 284 bcuciils 239-90 chemistry of 55-70 commercial development 4 commercial product 57-60 composition 59... 

Fifty years ago the editor of Pyre thrum Post reviewed an article in the US trade journal Pest Control utul Sanitation which described the powerful synergistic and stabilizing effects that the then novel compound piperonyl butoxide (PBO) had on pyrelhrins. The author claimed that the past popularity of aerosols was now likely to be greatly increased as the new combinations of pyrethrins and PBO had produced equal knockdown but greater mortality than any of the formulations previously used. 

Further support for the pro-insecticide concept was found using Colorado potato beetles that had been pretreated with piperonyl butoxide (PBO), an inhibitor of MFOs. In this study, chlorfenapyr (2) gave complete control at a dose rate of 10 ppm on the untreated insects. Treatment of the insects with PBO reduced the level of control to <10% [12]. 

No synergism in vivo (SRTD) was revealed with either piperonyl butoxide (PBO) or DEF-6 (looking for oxidative or hydrolytic metabolism)... 

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