Brevetoxin

Brevetoxin (PbTx), or brevetoxins, are a suite of cyclic polyether compounds produced naturally by a species of dinoflagellate

Dinoflagellate

The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth. About half of all dinoflagellates are photosynthetic, and these make up the...

 known as Karenia brevis

Karenia brevis

- Description :Karenia brevis is a marine dinoflagellate common in Gulf of Mexico waters, and is the organism responsible for Florida red tide, as well as red tide in Texas. K...

. Brevetoxins are neurotoxins that bind to voltage-gated sodium channels in nerve cells, leading to disruption of normal neurological processes and causing the illness clinically described as neurotoxic shellfish poisoning

Neurotoxic shellfish poisoning

Neurotoxic Shellfish Poisoning is caused by the consumption of shellfish contaminated by brevetoxins or brevetoxin analogs.Symptoms in humans include vomitting and nausea and a variety of neurologic symptoms such as slurred speech. No fatalities have been reported but there are a number of cases...

 (NSP).

Although brevetoxins are most well-studied in K. brevis, they are also found in other species of Karenia

Karenia (dinoflagellate)

Karenia is a genus of 12 species of dinoflagellates which were formerly included in the genus Gymnodinium.A number of species cause red tides, including Karenia brevis off the coast of Florida and Karenia mikimotoi which was first described in Japan, but is now found in the Atlantic ocean as well,...

and at least one large fish kill has been traced to brevetoxins in Chattonella.

	Brevetoxin A	Brevetoxin B
chemical structure
subtypes	Brevetoxin-1 (PbTx-1) R = -CH2C(=CH2)CHO Brevetoxin-7 (PbTx-7) R = -CH2C(=CH2)CH2OH Brevetoxin-10 (PbTx-10) R = -CH2CH(-CH3)CH2OH	Brevetoxin-2 (PbTx-2) R = -CH2C(=CH2)CHO Brevetoxin-3 (PbTx-3) R = -CH2C(=CH2)CH2OH Brevetoxin-8 (PbTx-8) R = -CH2COCH2Cl Brevetoxin-9 (PbTx-9) R = -CH2CH(CH3)CH2OH

Other Brevetoxins:

• Brevetoxin-5 (PbTx-5): like PbTx-3, but acetylated
  Acetylation
  Acetylation describes a reaction that introduces an acetyl functional group into an organic compound...
  
   hydroxyl
  Hydroxyl
  In chemistry, hydroxyl is composed of molecules consisting of an oxygen atom and a hydrogen atom connected by a covalent bond . The neutral form is a hydroxyl radical. The hydroxyl anion is called hydroxide; it is a diatomic ion with a charge of negative one...
  
   group in position 38.
• Brevetoxin-6 (PbTx-6): like PbTx-2, but double bond 27-28 is epoxidated
  Epoxide
  An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in...
  
  .

Brevetoxin-2 was synthesized in 1995 by K. C. Nicolaou and coworkers in 123 steps with 91% average yield (final yield ~9·10^-6).