Specific Regulation of Pyrethrin Biosynthesis in Chrysanthemum ..

THE PARTIAL SYNTHESIS OF PYRETHRINS AND CINERINS AND THEIR RELATIVE TOXICITIES

Intermediates for the synthesis of cis-pyrethrolone L

There is however a lack of quantitative information on the impact of water stress on flower biomass, pyrethrins synthesis, and the accumulation these actives in the flowers during key stages of flower development.

Insecticides Used in the Urban Environment: Mode of Action

()As part of a scheme to elucidate by synthetical methods the structuresof the cinerins and pyrethrins, the important insecticidal constituentsof pyrethrum flowers, one of us in 19461 synthesized2-but-2'-enyl-and 2-but-3'-enyl-3-methylcyclopent-2-enone (Ia and Ib)for comparison with cinerone, which is a degradation product ofcinerolone3.

These chemicals are known as chitin synthesis inhibitors or CSIs. They are often grouped with the IGRs. The most notable chemical being used as a CSI is the benzoyphenyl ureas. This class of insecticides includes lufenuron (Program®) which is a systemic insecticide used for flea control (fed to your pet), diflubenzuron (Dimilin®) used against fly larvae in manure, and hexaflumuron (Sentricon®) used in a termite bait station. These chemicals inhibit the production of chitin. Chitin is a major component of the insect exoskeleton. Insects poisoned with CSIs are unable to synthesize new cuticle, thereby preventing them from molting successfully to the next stage.