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Stereospecificity in toxicity of the optical isomers of EPN


While the optical isomers of EPN were equally toxic to mice, (+)-EPN was 2.9 fold and 4.0 fold more toxic to houseflies and rice stem borer larvae, respectively, than the (−)-isomer. In addition, (−)-EPN produced paralysis of the legs in hens about 10 to 14 days after dosing, whereas (+)-EPN caused no paralytic effects. Thus, (+)-EPN appears to be a more appropriate insecticide than the racemic compound, since it combines high toxicity to insects and no delayed neurotoxicity in hens.

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Ohkawa, H., Mikami, N., Okuno, Y. et al. Stereospecificity in toxicity of the optical isomers of EPN. Bull. Environ. Contam. Toxicol. 18, 534–540 (1977).

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  • Sciatic Nerve
  • Malathion
  • Neurotoxicity
  • Insecticidal Activity
  • TOCP