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Novel Compounds Show Promise As Safer, More Potent Insecticides

Date:
August 28, 2005
Source:
American Chemical Society
Summary:
Research teams at Nihon Nohyaku Co., Ltd., Bayer CropScience and DuPont have developed two new classes of broad-spectrum insecticides that show promise as a safer and more effective way to fight pest insects that damage food crops. The insecticides, which represent the first synthetic compounds designed to activate a novel insecticide target called the ryanodine receptor, may also help tackle the growing problem of insecticide resistance, the researchers say.
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WASHINGTON, Aug. 28 — Research teams at Nihon Nohyaku Co.,Ltd., Bayer CropScience and DuPont have developed two new classes ofbroad-spectrum insecticides that show promise as a safer and moreeffective way to fight pest insects that damage food crops. Theinsecticides, which represent the first synthetic compounds designed toactivate a novel insecticide target called the ryanodine receptor, mayalso help tackle the growing problem of insecticide resistance, theresearchers say. They described their studies today at the 230thnational meeting of the American Chemical Society, the world’s largestscientific society.

Many of the most widely used insecticidestoday act on only a handful of exploited targets, including theorganophosphates, which block acetylcholinesterase, an enzyme thathelps control nerve activity. Some experts are concerned that theseolder, less-selective insecticides could pose heath risks and there’s agrowing effort underway to find safer replacements.

Targeting theryanodine receptor may offer a promising alternative, researchers say.Ryanodine, a natural alkaloid discovered years ago in a species oftropical plant, has been used to study muscle physiology in a widevariety of organisms, including insects and mammals. Ryanodinereceptors regulate muscle and nerve activities by modifying levels ofinternal calcium in these cells. These receptors exist in both mammalsand insects but have distinct differences. Researchers have known thatryanodine itself has insecticidal properties, but no syntheticmolecules had previously been identified that potently and selectivelytarget these receptors in insects, until now.

Nihon Nohyaku Co.,Ltd., based in Japan, and Bayer CropScience AG in Germany have jointlydeveloped Flubendiamide, the first example of the phthalic aciddiamides, a novel class of insecticides that activate the ryanodinereceptor. The insecticide is highly effective against many differentspecies of caterpillars, says Masanori Tohnishi, a senior researchscientist at Nihon Nohyaku. In early tests, the compound showed highactivity against the tobacco budworm (Heliothis virescens), which isknown to cause serious damage to cotton, tobacco and other crops, theresearchers say. The compound did not have any measurable effect onmammalian ryanodine receptors, according to Peter Lümmen, Ph.D., aresearch scientist at Bayer CropScience.

DuPont, based inWilmington, Del., is developing another group of compounds that targetthe ryanodine receptor. Called anthranilic diamides, these novelcompounds show excellent control of pest insects with exceptionalmammalian safety, according to the researchers. They were the first todemonstrate the mode of action of these ryanodine receptor-activemolecules, says Daniel Cordova, a researcher at DuPont Crop Protection.

Bothclasses of compounds are believed to have high potency, the researcherssay, although they are structurally different. Both insecticides arestill in developmental stages.

The research team at DuPont saysthey have cloned ryanodine receptors from several insect species andthat these receptors may help provide a better understanding of theirrole in calcium signaling, which could lead to new insights into humandiseases.

The American Chemical Society is a nonprofitorganization, chartered by the U.S. Congress, with a multidisciplinarymembership of more than 158,000 chemists and chemical engineers. Itpublishes numerous scientific journals and databases, convenes majorresearch conferences and provides educational, science policy andcareer programs in chemistry. Its main offices are in Washington, D.C.,and Columbus, Ohio.


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Cite This Page:

American Chemical Society. "Novel Compounds Show Promise As Safer, More Potent Insecticides." ScienceDaily. ScienceDaily, 28 August 2005. <www.sciencedaily.com/releases/2005/08/050828095638.htm>.
American Chemical Society. (2005, August 28). Novel Compounds Show Promise As Safer, More Potent Insecticides. ScienceDaily. Retrieved July 17, 2024 from www.sciencedaily.com/releases/2005/08/050828095638.htm
American Chemical Society. "Novel Compounds Show Promise As Safer, More Potent Insecticides." ScienceDaily. www.sciencedaily.com/releases/2005/08/050828095638.htm (accessed July 17, 2024).

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