The allethrins are a group of related synthetic compounds used in

insecticides Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

. They are classified as

pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and ''Chrysanthemum coccineum, C. coccineum''). Pyrethroids are used as commercial and hou ...

s, i.e. synthetic versions of

pyrethrin The pyrethrins are a class of organic compounds normally derived from ''Chrysanthemum cinerariifolium'' that have potent Insecticide, insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum f ...

, a chemical with insecticidal properties found naturally in ''

Chrysanthemum Chrysanthemums (), sometimes called mums or chrysanths, are flowering plants of the genus ''Chrysanthemum'' in the family Asteraceae. They are native to East Asia and northeastern Europe. Most species originate from East Asia and the center ...

'' flowers. They were first synthesized in the United States by Milton S. Schechter in 1949. Allethrin was the first

. They are commonly used in

ultra-low volume Ultra-low volume (ULV) application of pesticides has been defined as spraying at Volume Application Rate(VAR) of less than 5 L/ha for field crops or less than 50 L/ha for tree/bush crops. VARs of 0.25 – 2 L/ha are typical for aerial ULV appl ...

sprays for outdoor

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

control, and in many household insecticides such as

RAID Raid, RAID or Raids may refer to: Attack * Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground * Corporate raid, a type of hostile takeover in business * Panty raid, a prankish raid by male college ...

, as well as

mosquito coil A mosquito coil is a mosquito-repelling incense, usually made into a spiral, and typically made using dried paste of pyrethrum powder. The coil is usually held at the center of the spiral, suspending it in the air, or wedged by two pieces of fir ...

Chemical structure

Allethrin I and allethrin II differ by having a

methyl group In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

and a

methyl ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fa ...

, respectively, on one terminus. Each of these allethrins consists of the eight possible

stereoisomer In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...

s. 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 Bioallethrin is a brand name for an ectoparasiticide. It consists of two of the eight stereoisomers of allethrin I in an approximate ratio of 1:1. The name ''Bioallethrin'' is a registered trademark of Sumitomo Chemical. ''Esbiothrin'' (CAS number ...

Toxicity

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

isoform A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isof ...

s of

glucuronosyltransferase Uridine 5'-diphospho-glucuronosyltransferase ( UDP-glucuronosyltransferase, UGT) is a microsomal glycosyltransferase () that catalyzes the transfer of the glucuronic acid component of UDP-glucuronic acid to a small hydrophobic molecule. This is ...

, which serve in hepatic detoxifying metabolism pathways.

Notes

References

*Oregon State University (1996)
Allethrin
Retrieved October 26, 2005. *Illinois Department of Public Health

Retrieved October 26, 2005. *

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...

(WHO)
d-Allethrin
Retrieved October 26, 2005. *Jim E. Riviere & Mark G. Papich Eds.: Veterinary Pharmacology and Therapeutics. Iowa State University Press, 2009. . (p. 1194)

External links

Pyrethrins and Pyrethroids Fact Sheet - National Pesticide Information Center
{{insecticides Pyrethroids Enones Cyclopentenes