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Pyrethrin
The pyrethrins are a class of organic compounds normally derived from ''Chrysanthemum cinerariifolium'' that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants.Mader, Eric, and Nancy Lee Adamson. "Organic-Approved Pesticides."Organic-Approved Pesticides (n.d.): n. pag. The Xerxes Society. The Xerces Society for Invertebrate Conservation, Oct. 2012. Web. 10 Mar. 2015. Their insecticidal and insect-repellent properties have been known and used for thousands of years. Pyrethrins are gradually replacing organophosphates and organochlorides as the pesticides of choice as the latter compounds have been shown to have significant and persistent toxic effects to humans.They first appeared on markets in the 1900's and have been continually used since then in products such as bug bombs, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrethrin
The pyrethrins are a class of organic compounds normally derived from ''Chrysanthemum cinerariifolium'' that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants.Mader, Eric, and Nancy Lee Adamson. "Organic-Approved Pesticides."Organic-Approved Pesticides (n.d.): n. pag. The Xerxes Society. The Xerces Society for Invertebrate Conservation, Oct. 2012. Web. 10 Mar. 2015. Their insecticidal and insect-repellent properties have been known and used for thousands of years. Pyrethrins are gradually replacing organophosphates and organochlorides as the pesticides of choice as the latter compounds have been shown to have significant and persistent toxic effects to humans.They first appeared on markets in the 1900's and have been continually used since then in products such as bug bombs, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrethrin II
The pyrethrins are a class of organic compounds normally derived from '' Chrysanthemum cinerariifolium'' that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants.Mader, Eric, and Nancy Lee Adamson. "Organic-Approved Pesticides."Organic-Approved Pesticides (n.d.): n. pag. The Xerxes Society. The Xerces Society for Invertebrate Conservation, Oct. 2012. Web. 10 Mar. 2015. Their insecticidal and insect-repellent properties have been known and used for thousands of years. Pyrethrins are gradually replacing organophosphates and organochlorides as the pesticides of choice as the latter compounds have been shown to have significant and persistent toxic effects to humans.They first appeared on markets in the 1900's and have been continually used since then in products such as bug bombs, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrethrum
''Pyrethrum'' was a genus of several Old World plants now classified as ''Chrysanthemum'' or ''Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants formerly included in the genus ''Pyrethrum''. Pyrethrum is also the name of a natural insecticide made from the dried flower heads of '' Chrysanthemum cinerariifolium'' and ''Chrysanthemum coccineum''. The insecticidal compounds present in these species are pyrethrins. Description Some members of the genus ''Chrysanthemum'', such as the following two, are placed in the genus ''Tanacetum'' instead by some botanists. Both genera are members of the daisy (or aster) family, Asteraceae. They are all perennial plants with a daisy-like appearance and white petals. * '' Tanacetum cinerariifolium'' is called the Dalmatian chrysanthemum, denoting its origin in that region of the Balkans (Dalmatia). It looks more like the common daisy than other pyrethrums do. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piperonyl Butoxide
Piperonyl butoxide (PBO) is a pale yellow to light brown liquidNational Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. organic compound used as a synergist component of pesticide formulations. That is, despite having no pesticidal activity of its own, it enhances the potency of certain pesticides such as carbamates, pyrethrins, pyrethroids, and rotenone. It is a semisynthetic derivative of safrole.Robert L. Metcalf "Insect Control" in Ullmann’s Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2002. History PBO was developed in the late 1930s and early 1940s to enhance the performance of the naturally derived insecticide pyrethrum. Pyrethrum is and was an important insecticide against mosquitoes and other disease-carrying vectors, thereby providing public health benefits, e.g., preventing malaria. Although exhibi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrethroids
A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and '' C. coccineum''). Pyrethroids are used as commercial and household insecticides. In household concentrations pyrethroids are generally harmless to humans. However, pyrethroids are toxic to insects such as bees, dragonflies, mayflies, gadflies, and some other invertebrates, including those that constitute the base of aquatic and terrestrial food webs. Pyrethroids are toxic to aquatic organisms, especially fish.Pyrethroids fact sheet from the Illinois Department of Public Health. They have been shown to be an effective control measure for malaria outbreaks, through indoor applications. Mode of action Pyreth ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persian Powder
:''The term Persian powder can also refer to a type of dry snow in the Zagros Mountains.'' Persian powder is an insecticide powder. It is also known as Persian pellitory and insect powder. Biological pest control Persian powder is a green pesticide that has been used for centuries for the biological pest extermination of household insects, garden pests, and agricultural pests.''Bioaromatica'The history of pyrethrum It is used indoors, in gardens and the horticulture industry, and in agriculture. It is produced from the powdered flowers of certain species of pyrethrum, plants in the genera ''Chrysanthemum'' and ''Tanacetum''. In more recent times it has had formulations with brand names such as Zacherlin. Synthetic forms Pyrethroids are synthetic insecticides based on natural pyrethrum ( pyrethrins), such as permethrin. A common formulation of pyrethrin is in preparations containing the synthetic chemical piperonyl butoxide: this has the effect of enhancing the toxicity to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrethrin I
Pyrethrin I is one of the two pyrethrins, natural organic compounds with potent insecticidal activity. It is an ester of (+)-''trans''- chrysanthemic acid with (''S'')-(''Z'')- pyrethrolone. Total synthesis The synthesis of pyrethrin I involves the esterification of (+)-''trans''-chrysanthemic acid with (S)-(Z)-pyrethrolone. One synthetic method for each of these is shown in the images below. Sobti and Dev of the Malti-Chem Research Centre in Nadesari, vadodara, India published this method for chrysanthemic acid in 1974. The starting material for the synthesis uses commercially available (+)-3α, 4α-epoxycarane (1). A lactone is eventually formed and the ring is opened by the use of a Grignard reagent to give (+)-trans-chrysanthemic acid. The preparation of (''S'')-pyrethrolone is essentially a 2 step synthesis. The starting material (S)-4-hydroxy-3-methyl-2-(2-propynyl)-2-cyclopenten-1-one (7) is also commercially available as the alcohol moiety of ETOC. Tetrakis(triphenylphos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 of diversity is in China.Liu, P. L., et al. (2012)Phylogeny of the genus ''Chrysanthemum'' L.: Evidence from single-copy nuclear gene and chloroplast DNA sequences.''PLOS One'' 7(11), e48970. . Countless horticultural varieties and cultivars exist. Description The genus ''Chrysanthemum'' are perennial herbaceous flowering plants, sometimes subshrubs. The leaves are alternate, divided into leaflets and may be pinnatisect, lobed, or serrate (toothed) but rarely entire. The compound inflorescence is an array of several flower heads, or sometimes a solitary head. The head has a base covered in layers of phyllaries. The simple row of ray florets is white, yellow, or red. The disc florets are yellow. Pollen grains are approximately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrysanthemic Acid
Chrysanthemic acid is an organic compound that is related to a variety of natural and synthetic insecticides. It is related to the pyrethrin I and II, as well as the pyrethroids. One of the four stereoisomers, (1''R'',3''R'')- or (+)-''trans''-chrysanthemic acid (pictured), is the acid part of the ester pyrethrin I, which occurs naturally in the seed cases of ''Chrysanthemum cinerariaefolium''. Many synthetic pyrethroids, for example the allethrins, are esters of all four stereoisomers. Staudinger and Ružička named chrysanthemic acid in 1924.H. Staudinger, L. Ružička: "Insektentotende Stoffe H. Zur Konstitution der Chrysanthemummonocarbonsiiure und -dicarbonsiiure", Helv. Chem. Acta 7 (1924) 201 Biosynthesis Chrysanthemic acid is derived from its pyrophosphate ester, which in turn is produced naturally from two molecules of dimethylallyl diphosphate. Industrial synthesis Chrysanthemic acid is produced industrially in a cyclopropanation reaction of a diene In or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insecticide
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 be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain. Insecticides can be classified into two major groups: systemic insecticides, which have residual or long term activity; and contact insecticides, which have no residual activity. The mode of action describes how the pesticide kills or inactivates a pest. It provides another way of classifying insecticides. Mode of action can be important in understanding whether an insecticide will be toxic to unrelated species, such as fish, birds and mammals. Insecticides may be repellen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrysanthemum Cinerariifolium
''Tanacetum cinerariifolium'' is a species of flowering plant in the aster family, Asteraceae, and formerly part of the genus ''Pyrethrum'', but now placed in the genus ''Chrysanthemum'', or the genus ''Tanacetum'' by some biologists. It is called the Dalmatian chrysanthemum, denoting its origin in that region of Europe (Dalmatia). It looks more like the common daisy than other pyrethrums do. Its flowers, typically white with yellow centers, grow from numerous fairly rigid stems. Plants have blue-green leaves and grow to 45 to 100 cm (18 to 39 in) in height. As an insecticide The plant is economically important as a natural source of an insecticide called "pyrethrum." The flowers are pulverized and the active components, called pyrethrins, contained in the seed cases, are extracted and sold in the form of an oleoresin. This is applied as a suspension in water or oil, or as a powder. Pyrethrins attack the nervous systems of all insects, and inhibit female mosquitoes from bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Staudinger
Hermann Staudinger (; 23 March 1881 – 8 September 1965) was a German organic chemist who demonstrated the existence of macromolecules, which he characterized as polymers. For this work he received the 1953 Nobel Prize in Chemistry. He is also known for his discovery of ketenes and of the Staudinger reaction. Staudinger, together with Leopold Ružička, also elucidated the molecular structures of pyrethrin I and II in the 1920s, enabling the development of pyrethroid insecticides in the 1960s and 1970s. Early work Staudinger was born in 1881 in Worms. Staudinger, who initially wanted to become a botanist, studied chemistry at the University of Halle, at the TH Darmstadt and at the LMU Munich. He received his "Verbandsexamen" (comparable to Master's degree) from TH Darmstadt. After receiving his Ph.D. from the University of Halle in 1903, Staudinger qualified as an academic lecturer at the University of Strasbourg in 1907. It was here that he discovered the ketenes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
