Allethrins

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Allethrin I (R = -CH3)
Allethrin II (R = -COOCH3) Allethrin 2D.svg
Allethrin I (R = −CH3)
Allethrin II (R = −COOCH3)

The allethrins are a group of related synthetic compounds used in insecticides. They are classified as pyrethroids, i.e. synthetic versions of pyrethrin, a chemical with insecticidal properties found naturally in Chrysanthemum flowers. They were first synthesized in the United States by Milton S. Schechter in 1949. Allethrin was the first pyrethroid. [1]

Contents

They are commonly used in ultra-low volume sprays for outdoor mosquito control, and in many household insecticides such as RAID, as well as mosquito coils.

Chemical structure

Allethrin I and allethrin II differ by having a methyl group and a methyl ester, respectively, on one terminus. Each of these allethrins consists of the eight possible stereoisomers. A partly enantiopure variant of allethrin I, consisting of only two stereoisomers in an approximate ratio of 1:1, is called bioallethrin. The same mixture of isomers, but in an approximate ratio of 3:1, is known as esbiothrin.

Toxicity

Chronic exposure to allethrins alters the plasma biochemical profile of humans and may have adverse health effects. [2] Bioallethrin has been shown to cause oxidative damage, cellular toxicity and necrosis of human lymphocytes studied in vitro. [3] It is highly toxic to fish and aquatic invertebrates. At normal application rates, allethrin is slightly toxic to bees. [4] Insects subject to exposure become paralyzed (nervous system effect) before dying. Allethrins are toxic to cats [5] because they either do not produce, or produce less of certain isoforms of glucuronosyltransferase, which serve in hepatic detoxifying metabolism pathways. [6]

Notes

  1. Ujihara, Kazuya (25 July 2019). "The history of extensive structural modifications of pyrethroids". Journal of Pesticide Science. 44 (4): 215–224. doi:10.1584/jpestics.D19-102. PMC   6861428 . PMID   31777441.
  2. Narendra, M.; Kavitha, G.; Helah Kiranmai, A.; Raghava Rao, N.; Varadacharyulu, N.C. (September 2008). "Chronic exposure to pyrethroid-based allethrin and prallethrin mosquito repellents alters plasma biochemical profile". Chemosphere. 73 (3): 360–364. Bibcode:2008Chmsp..73..360N. doi:10.1016/j.chemosphere.2008.05.070. PMID   18657844.
  3. Arif, Amin; Quds, Ruhul; Mahmood, Riaz (December 2021). "Bioallethrin enhances generation of ROS, damages DNA, impairs the redox system and causes mitochondrial dysfunction in human lymphocytes". Scientific Reports. 11 (1): 8300. doi:10.1038/s41598-021-87799-3. PMC   8050322 . PMID   33859309.
  4. "Pesticide Information Profile - Allethrin". pmep.cce.cornell.edu.
  5. "Pyrethrin and Permethrin Toxicity in Dogs and Cats". peteducation.com. Archived from the original on 2024-05-26. Retrieved 2013-05-12.
  6. Court, M. H.; Greenblatt, D. J. (2000). "Molecular genetic basis for deficient acetaminophen glucuronidation by cats: UGT1A6 is a pseudogene, and evidence for reduced diversity of expressed hepatic UGT1A isoforms". Pharmacogenetics. 10 (4): 355–369. doi:10.1097/00008571-200006000-00009. PMID   10862526.

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