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|Symptoms, Treatment, Decontamination|
|Onset of Symptoms||Rapid, with death occurring within minutes.|
|Rapid diagnostic assay||No.|
|Antidote||Vasodilators are effective if delivered immediately by injection into the ventricle of the heart. The most effective are papverine and isosorbide dinitrate. If exposure is expected, pretreatment with hydrocortisone an hour beforehand may offer protection.|
|Supportive Care||Treatment of symptoms, probably as for a coronary spasm.|
|Inactivation||Palytoxins are stable in seawater and lower alcohols.|
Intraperitoneal LD50 in mice is <100 ng/kg, putting it in the same class as botulin. Generally speaking, the LD50 is in this range for intravenous and intraperitoneal routes for all mammals tested.
|CAS Registry Number|
|Solubility||Very soluble in water.|
|pKa in water|
|Yes, but unlikely to be practical.|
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Palytoxin acts at the cell membranes to make them permeable to cations - positively charged ions, typically sodium, potassium, and calcium. Many functions of cells depend upon controlling the flow of these ions in and out of the cell, so disrupting this traffic is very dangerous.
At the physiological level, the most sensitive target is the myocardium, or muscular component of the heart, and the primary effect is vasoconstriction or rapid narrowing of blood vessels in the heart and in the lungs. Another effect is hemolysis, or the destruction of the red blood cells. These three effects taken together cut off the oxygen supply and the victim suffocates.
Palytoxin was first isolated from the soft coral Palythoa toxica. Several species of Palythoa are used in aquariums, but do not produce the toxin. Originally, it was only found in a single tidal pool on the island of Maui in Hawaii and native Hawaiians used to coat spear points with a red seaweed from the pool. Toxin-containing corals appear to be randomly and sparingly distributed throughout the South Pacific and there is now a school of thought that suggests that the coral is simply concentrating the toxin made by a dinoflagellate (a small single-celled organism) called Ostreopis siamensis.
Palytoxin is the most toxic natural product known, it is estimated that the lethal dose for a human is less than five micrograms. Supplies are extremely limited as it is only found at low concentrations in the corals that do contain it, although this may change if a microbial source is found.
Palytoxin is an incredibly complex molecule with 64 stereocenters and a backbone of 115 contiguous carbon atoms. Most chemists would believe it to be beyond the capabilities of modern chemistry to make it in the laboratory, but this was managed in 1989.
|Toxic effects of contact |
with other marine life
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