Maitotoxin

Maitotoxin-3D-vdW

Maitotoxin is a potent marine toxin produced by the dinoflagellate species Gambierdiscus toxicus. It is one of the most toxic non-protein substances known and is a significant contributor to ciguatera fish poisoning.

Structure and Properties

Maitotoxin is a large and complex polyether compound. Its molecular formula is C164H256O68S2Na2, and it has a molecular weight of approximately 3,422 Da. The structure of maitotoxin includes multiple ether rings and sulfate groups, contributing to its high solubility in water and its potent biological activity.

Biological Activity

Maitotoxin is known for its ability to activate calcium channels in cell membranes, leading to an influx of calcium ions. This influx can cause a variety of cellular responses, including cell death. The toxin's mechanism of action involves the activation of phospholipase C, which in turn generates inositol triphosphate (IP3) and diacylglycerol (DAG), leading to the release of calcium from intracellular stores.

Toxicity

Maitotoxin is extremely toxic, with an LD50 (lethal dose for 50% of the population) in mice of approximately 50 ng/kg when administered intraperitoneally. It is considered one of the most potent marine toxins, and exposure can lead to severe symptoms, including cardiovascular collapse, respiratory failure, and death.

Sources and Occurrence

Maitotoxin is produced by the dinoflagellate Gambierdiscus toxicus, which is found in tropical and subtropical waters. This organism is often associated with ciguatera fish poisoning, a type of foodborne illness that occurs when humans consume fish contaminated with ciguatoxins and maitotoxin.

Detection and Analysis

Detection of maitotoxin in environmental samples and seafood is typically performed using high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS). These techniques allow for the precise identification and quantification of the toxin.

Prevention and Treatment

There is currently no specific antidote for maitotoxin poisoning. Treatment is primarily supportive and symptomatic, focusing on managing the cardiovascular and respiratory symptoms. Preventive measures include monitoring and controlling the populations of Gambierdiscus toxicus in affected waters and avoiding the consumption of fish known to be at risk of ciguatera contamination.

Related Pages

• Ciguatera fish poisoning
• Dinoflagellate
• Marine toxin
• Calcium channel
• Phospholipase C