Synthetic pyrethroid modeled pyrethrin

Figure 7. Synthetic Pyrethroid modeled on pyrethrin natural insecticide found in Chrysanthemum cinerariaefli...

Many pesticides are not as novel as they may seem. Some, such as the pyre-throid and neonicotinoid insecticides, are modeled on natural insecticides. Synthetic pyrethroids are related to the natural pyrethrins (see Chapter 12), whereas the neo-nicotinoids share structural features with nicotine. In both cases, the synthetic compounds have the same mode of action as the natural products they resemble. Also, the synthetic pyrethroids are subject to similar mechanisms of metabolic detoxication as natural pyrethrins (Chapter 12). More widely, many detoxication mechanisms are relatively nonspecific, operating against a wide range of compounds that... 

The compounds featured in Table 1.1 are considered briefly here. Pyrethrins are lipophilic esters that occur in Chrysanthemum spp. Extracts of flower heads of Chrysanthemum spp. contain six different pyrethrins and have been used for insect control (Chapter 12). Pyrethrins act upon sodium channels in a manner similar to p,p -DDT. The highly successful synthetic pyrethroid insecticides were modeled on natural pyrethrins. 

The development of the pyrethroids from the pyrethrins serves as an example of the most successful development of a commercially important synthetic insecticide from a natural precursor. The commercial pyrethroids are among the most active insecticides known and they control a wider range of insect and acarid pests at lower application rates than most other insecticides. Their high toxicity to insects and low mammalian toxicity make these compounds a role model for all present and future insecticides. 

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