Saxitoxin: essential data

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Saxitoxin: essential data
Symptoms and Treatment, Toxicity, Chemistry, Site of Action, Sources, Properties, Terrorist Interest, IDC Codes
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Symptoms, Treatment, Decontamination
Syndrome Name	Paralytic Shellfish Poisoning
Symptoms	Tingling, numbness, weakness, limp paralysis Note:Symptoms can be confused with other poisonings, including: Botulism, Ciguatera poisoning Gastroenteritis Insecticide poisoning Fugu (tetrodotoxin) poisoning
Onset of Symptoms	Almost immediate. Exposure by inhalation leads to extremely rapid development of symptoms with death occurring within minutes if not treated.
Rapid diagnostic assay	None available
Antidote	None available
Supportive Care	Artificial respiration to support breathing
Inactivation	Inactivated by strong alkalis

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Toxicity in Mice
Route	LD₅₀(micrograms/kg)
Intravenous	3-9
Intraperitoneal	10
Oral	263
Inhalation	<2 (in hamsters)

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Chemical Properties
Structure
CA Name	1H,10H-Pyrrolo[1,2-c]purine-10,10-diol, 2,6-diamino-4-[[(aminocarbonyl)oxy]methyl]- 3a,4,8,9-tetrahydro-, (3aS,4R,10aS)-
Trivial Names	(+)-Saxitoxin Saxitoxin hydrate STX
Registry Number	35523-89-8
RTECS Number	UY8708500
Molecular Formula	C₁₀H₁₇N₇O₄
Molecular weight	299.3
Solubility	Freely soluble in water and methanol. Limited solubility in ethanol and acetic acid. Insoluble in lipid solvents
pKa in water	8.24
Complete synthesis	Yes, but impractical.
Note:Although saxitoxin is the most toxic member of the family, there are almost two dozen related compounds found in nature.

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Site of Action

Saxitoxin binds to the sodium channel of the nerve preventing the passage of sodium ions through the cell membrane and therefore blocks passage of the nerve impulse.

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Source

Exposure to saxitoxin typically comes from eating shellfish contaminated by "red tides" or algal blooms of Alexandrium catenella (formerly Gonyaulax catenella) or A. tamarense-excavatum (formerly G. tamarensis.)

G. catenella has been cultured and cultures in an artificial sea water-like medium supplemented with some minerals and vitamins to give the toxin in good yield. Saxitoxin for research use is usually extracted from the siphons of clams contaminated by red tide.

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Agent Properties

Saxitoxin is readily soluble in water and can be dispersed in aerosols. People walking near the surfline during red tide events often complain of sore throats and difficulty breathing. This is as a result of inhaling a toxin-laden aerosol generated by the pounding surf. Most often this is not due to saxitoxin, but to another group of shellfish poisons, the neurological shellfish poisons or brevetoxins, but the effectiveness of these toxins is demonstrated by this phenomenon.

Saxitoxin is toxic by ingestion and by inhalation, with inhalation leading to rapid respiratory collapse and death. Chemically, saxitoxin is stable, although it can be inactivated by treatment with strong alkali.

Saxitoxin has also been reported to have been tested as a coating for bullets. Apparently, it is stable enough to survive the hot gases of the detonation and significantly increased mortality.

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