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|Section2= |Section6= |Section7= }} Spinosad is an insecticide based on chemical compounds found in the bacterial species ''Saccharopolyspora spinosa''. The genus of ''Saccharopolyspora'' was discovered in 1985 in isolates from crushed sugar cane which produce yellowish-pink aerial hyphae, with bead-like chains of spores enclosed in a characteristic hairy sheath. This genus is defined as aerobic, gram-positive, non-acid-fast actinomycetes with fragmenting substrate mycelium. ''S. spinosa'' was isolated from soil collected inside a non-operational sugar mill rum still in the Virgin Islands. Spinosad is a mixture of chemical compounds in the spinosyn family that has a generalized structure consisting of a unique tetracyclic ring system attached to an amino sugar (D-forosamine) and a neutral sugar (tri-''Ο''-methyl-L-rhamnose). Spinosad is relatively non-polar and not easily dissolved in water. Spinosad is a novel mode-of-action insecticide derived from a family of natural products obtained by fermentation of ''S. spinosa''. Spinosyns occur in over 20 natural forms, and over 200 synthetic forms (spinosoids) have been produced in the lab. Spinosad contains a mix of two spinosoids, spinosyn A, the major component, and spinosyn D (the minor component), in an approximately 17:3 ratio.〔 ==Mode of action== Spinosad is highly active, by both contact and ingestion, to numerous insect species. Spinosad’s overall protective effect varies with insect species and life stage. Spinosad affects certain species only in the adult stage, but can affect other species at more than one life stage. The species that are subject to very high rates of mortality as larvae, but not as adults, may gradually be controlled through sustained larval mortality.〔 The mode of action of spinosoid insecticides is via a neural mechanism. The spinosyns and spinosoids have a novel mode of action, primarily targeting binding sites on nicotinic acetylcholine receptors (nAChRs) of the insect nervous system that are distinct from those at which other insecticides have their activity. Spinosoid binding leads to disruption of acetylcholine neurotransmission.〔 Spinosad also has secondary effects as a Ɣ-amino-butyric acid (GABA) neurotransmitter agonist.〔 Spinosad kills insects via hyperexcitation of the insect nervous system.〔 Spinosad so far has proven non cross-resistant to any other known insecticide. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Spinosad」の詳細全文を読む スポンサード リンク
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