Brevetoxin
 |
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2010) |
Brevetoxin (PbTx), or brevetoxins, are a suite of cyclic polyether compounds produced naturally by a species of dinoflagellate known as Karenia brevis. 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 (NSP).[1]
Although brevetoxins are most well-studied in K. brevis, they are also found in other species of Karenia and at least one large fish kill has been traced to brevetoxins in Chattonella.[1]
| Brevetoxin A [2] | Brevetoxin B [3] | |
|---|---|---|
| chemical structure |
 |
 |
| subtypes |
|
|
Other Brevetoxins:
- Brevetoxin-5 (PbTx-5): like PbTx-3, but acetylated hydroxyl group in position 38.
- Brevetoxin-6 (PbTx-6): like PbTx-2, but double bond 27-28 is epoxidated.
Brevetoxin-B was synthesized in 1995 by K. C. Nicolaou and coworkers in 123 steps with 91% average yield (final yield ~9·10−6).[4] and in 2004 a total of 90 steps with an average 93% yield for each step (0.14% overall). [3]
K. C. Nicolaou and coworkers reported their synthesis of Brevetoxin-1 in 1998.[5] In 2009, Michael Crimmins and co-workers reported their synthesis of Brevetoxin-1 as well.[6]
[edit] Biosynthesis
A proposed biosynthetic route includes a novel polyketide formation involving Claisen condensation of a dicarboxylic acid with the alpha-position of the second carboxylic function with a loss of a carboxyl group.[7]
[edit] References
- ^ a b Watkins, Sm; Reich, A; Fleming, Le; Hammond, R (2008), "Neurotoxic shellfish poisoning" (Free full text), Marine drugs 6 (3): 431–55, doi:10.3390/md20080021, PMC 2579735, PMID 19005578
- ^ "Total synthesis of brevetoxin A. Nicolaou KC, Yang Z, Shi G, Gunzner JL, Agrios KA, Gärtner P.". Nature 392 (6673): 264–9. 1998 Mar 19.
- ^ a b Goh Matsuo, Koji Kawamura, Nobuyuki Hori, Hiroko Matsukura, and Tadashi Nakata (2004). "Total Synthesis of Brevetoxin-B". J. Am. Chem. Soc. 126: 14374-1437.
- ^ K.C. Nicolaou, F.P.J.T. Rutjes, E.A. Theodorakis, J. Tiebes, M. Sato, E. Untersteller (1995). "Total Synthesis of Brevetoxin B 3. The Final Strategy and Completion". J. Am. Chem. Soc. 117: 10252–10263.
- ^ Nature 1998, 392, 264-269
- ^ Org. Lett. 2009, 11 (2), 489-492
- ^ Hong-Nong Chou and Yuzuru Shimizu (1987). "Biosynthesis of Brevetoxins. Evidence for the Mixed Origin of the Backbone Carbon Chain and the Possible Involvement of Dicarboxylic Acids". J Am Chem Soc 109: 2184–218. doi:10.1021/ja00241a048. http://pubs.acs.org/doi/pdf/10.1021/ja00241a048.
[edit] See also
|
|||||||||||||
 |
This biochemistry article is a stub. You can help Wikipedia by expanding it. |
