Synergism carbamates

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 ... 

Muore field. H.H, (1958). Synergism of die carbamate insecticides. Coni rib. Bovck Thompson in si. 19, 501-507,... 

Pyrethrins are not the only materials that can be synergized by PBO - synthetic pyrethroids, carbamates and others can also be synergized. 

The synergic lie action of pipemnyl butoxide (PBO) with the major classes of insecticides - pyrelhrins. pyrethnyids, carbamates, organophosphales and many insect growth regulators - has ensured its continued use in the control of insects affecting humans and animals. 

The ability of PBO in synergize cholinesterase-inhibiting insecticides has often been ignored when the mode of action of PBO is discussed. Moore field (I95KJ presented detailed data on this subject and showed that both aromatic and heterocyclic carbamates can be potentiated with PBO. A graphical presentation of data is reproduced in Fig. 19.3 on the effect of adding PBO to iwo carbamate insecticides to control house flics. This is of particular interest in that application was only made to female flies by individual measured drops - much more precise and relevant to effective control than spray applications to Hies of both sexes. This was a classic demonstration of the powerful synergistic action of PRO... 

If the mechanism of the catalysis of isocyanate-alcohol reaction by tin carboxylates does indeed proceed via the alkoxide as proposed by Bloodworth and Davies (11), then the synergism of the amine to tin can readily be explained from the above equilibrium. The amine will assist in the alcoholysis step and speed up the decomposition of the tin-carbamate complex by the alcohol to the urethane and tin alkoxide. 

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