Carbamates are a class of organic compounds that contain the functional group NH₂CO₂R. They are derivatives of carbamic acid, which contains the amino (NH₂) and carbonyl (CO) groups. Carbamates can be prepared by reacting an amine with phosgene or a related compound, or by reacting an isocyanate with an alcohol.
Carbamates are widely used as pesticides, insecticides, and herbicides because of their ability to inhibit the activity of cholinesterase enzymes, which are involved in nerve impulse transmission. They work by binding irreversibly to the active site of cholinesterase, preventing it from breaking down the neurotransmitter acetylcholine. This results in an accumulation of acetylcholine at the synapse, leading to overstimulation of the nervous system and ultimately paralysis.
Carbamates are also used in the production of pharmaceuticals, such as the muscle relaxant drug, Meprobamate. Meprobamate works by enhancing the activity of the neurotransmitter GABA in the central nervous system, leading to relaxation and sedation.
Carbamates have been associated with several health risks, including respiratory and neurological effects, as well as a potential carcinogenicity. They are also known to have toxic effects on non-target organisms such as bees and other pollinators. Therefore, their use has been regulated in many countries.