Phenylpyrazole insecticides are a class of chemically-related broad-spectrum

insecticides Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, in ...

. The chemical structures of these insecticides are characterized by a central

pyrazole Pyrazole is an organic compound with the chemical formula, formula . It is a heterocycle characterized as an azole with a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in Arene substitution pattern, ortho-substi ...

ring with a

phenyl In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula , and is often represented by the symbol Ph (archaically φ) or Ø. The phenyl group is closely related to benzene and can be viewed as a benzene ...

group attached to one of the nitrogen atoms of the pyrazole.

History

Phenylpyrazole insecticides were developed in response to increasing

pesticide resistance Pesticide resistance describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest. Pest species evolve pesticide resistance via natural selection: the most resistant specimens su ...

to other chemicals. Now, along with

neonicotinoid Neonicotinoids (sometimes shortened to neonics ) are a class of neuro-active insecticides chemically similar to nicotine, developed by scientists at Royal Dutch Shell, Shell and Bayer in the 1980s. Neonicotinoids are among the widest-used insecti ...

s, they are some of the most widely-used pesticides.

Mode of Action

Phenylpyrazole insecticides function by blocking GABA-gated chloride channels in insects (

IRAC IRAC ( ) is an acronym that generally stands for: Issue, Rule, Application, and Conclusion. It functions as a methodology for legal analysis. The IRAC format is mostly used in hypothetical questions in law school and bar exams. Sections of an IR ...

group 2B). Mammals do not have this type of chloride channel, making them much less susceptible to its effects. However, they do have the capacity to disrupt

epithelial cells Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

in the human intestine and adversely impact human health.

Examples

Examples include: * acetoprole * ethiprole *

fipronil Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole insecticide class. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor ( IRAC group 2B) and glutamate-g ...

* flufiprole * pyraclofos * pyrafluprole *

pyriprole Pyriprole, sold under the brand name Prac-tic, is a veterinary medication used for dogs against external parasites such as fleas and ticks. Pyriprole is a phenylpyrazole derivative similar to fipronil. Although introduced (in the 2000s) and u ...

* pyrolan * vaniliprole

References

External links

* {{commons category inline, Phenylpyrazole insecticides, lcfirst=yes Pyrazoles Insecticides Synthetic insecticides