Allethrins
{{short description|Class of synthetic chemicals used as insecticides}}
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.{{cite journal |last1=Ujihara |first1=Kazuya |title=The history of extensive structural modifications of pyrethroids |journal=Journal of Pesticide Science |date=25 July 2019 |volume=44 |issue=4 |pages=215–224 |doi=10.1584/jpestics.D19-102 |pmid=31777441 |pmc=6861428 }}
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.{{cite journal |last1=Narendra |first1=M. |last2=Kavitha |first2=G. |last3=Helah Kiranmai |first3=A. |last4=Raghava Rao |first4=N. |last5=Varadacharyulu |first5=N.C. |title=Chronic exposure to pyrethroid-based allethrin and prallethrin mosquito repellents alters plasma biochemical profile |journal=Chemosphere |date=September 2008 |volume=73 |issue=3 |pages=360–364 |doi=10.1016/j.chemosphere.2008.05.070|pmid=18657844 |bibcode=2008Chmsp..73..360N }} Bioallethrin has been shown to cause oxidative damage, cellular toxicity and necrosis of human lymphocytes studied in vitro.{{cite journal |last1=Arif |first1=Amin |last2=Quds |first2=Ruhul |last3=Mahmood |first3=Riaz |title=Bioallethrin enhances generation of ROS, damages DNA, impairs the redox system and causes mitochondrial dysfunction in human lymphocytes |journal=Scientific Reports |date=December 2021 |volume=11 |issue=1 |pages=8300 |doi=10.1038/s41598-021-87799-3|pmid=33859309 |pmc=8050322 }} It is highly toxic to fish and aquatic invertebrates. At normal application rates, allethrin is slightly toxic to bees.{{cite web | url = http://pmep.cce.cornell.edu/profiles/extoxnet/24d-captan/allethrin-ext.html#5 | title = Pesticide Information Profile - Allethrin | publisher = pmep.cce.cornell.edu}} Insects subject to exposure become paralyzed (nervous system effect) before dying. Allethrins are toxic to cats{{cite web | url = http://www.peteducation.com/article.cfm?c=2+1677&aid=2252 | title = Pyrethrin and Permethrin Toxicity in Dogs and Cats | publisher = peteducation.com | access-date = 2013-05-12 | archive-url = https://archive.today/20240526154343/https://www.webcitation.org/6Gst21cUu?url=http://www.peteducation.com/article.cfm%3Fc=2+1677 | archive-date = 2024-05-26 | url-status = dead }} because they either do not produce, or produce less of certain isoforms of glucuronosyltransferase, which serve in hepatic detoxifying metabolism pathways.{{Cite journal | last1 = Court | first1 = M. H. | last2 = Greenblatt | first2 = D. J. | title = Molecular genetic basis for deficient acetaminophen glucuronidation by cats: UGT1A6 is a pseudogene, and evidence for reduced diversity of expressed hepatic UGT1A isoforms | journal = Pharmacogenetics | volume = 10 | issue = 4 | pages = 355–369 | year = 2000 | pmid = 10862526 | doi=10.1097/00008571-200006000-00009}}
Notes
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References
{{more footnotes|date=March 2014}}
- Oregon State University (1996). [http://extoxnet.orst.edu/pips/allethri.htm Allethrin]. Retrieved October 26, 2005.
- Illinois Department of Public Health [http://www.idph.state.il.us/envhealth/factsheets/pyrethroid.htm Pyrethroid Insecticides Fact Sheet]. Retrieved October 26, 2005.
- World Health Organization (WHO) [http://webarchive.loc.gov/all/20041227231112/http://www.who.int/whopes/quality/en/dAllethrin_spec_eval_March_04.pdf d-Allethrin]. Retrieved October 26, 2005.
- Jim E. Riviere & Mark G. Papich Eds.: Veterinary Pharmacology and Therapeutics. Iowa State University Press, 2009. {{ISBN|9780813820613}}. (p. 1194)
External links
- [http://npic.orst.edu/factsheets/pyrethrins.pdf Pyrethrins and Pyrethroids Fact Sheet - National Pesticide Information Center]
- [http://extoxnet.orst.edu/pips/allethri.htm Allethrin Pesticide Information Profile - Extension Toxicology Network]
{{insecticides}}