Amanitins are a group of toxic peptides found in various species of the Amanita genus of mushrooms. These peptides are responsible for the majority of the toxic effects associated with Amanita mushroom poisoning. Amanitins are specifically categorized as cyclopeptides, as they consist of a cyclic structure of amino acids.
The most notable and potent amanitin compound is α-amanitin, which is found in high concentrations in the green-spored death cap mushroom (Amanita phalloides). Other amanitins include β-amanitin, γ-amanitin, and ε-amanitin, although they are generally less abundant in Amanita species.
Amanitins are highly toxic due to their ability to inhibit RNA polymerase II, an enzyme involved in the transcription process of messenger RNA (mRNA) synthesis. By binding tightly to RNA polymerase II, amanitins prevent the enzyme from functioning properly, ultimately disrupting protein synthesis.
The effects of amanitins are not immediately apparent and tend to develop gradually over hours or even days after ingestion. Symptoms of amanitin poisoning can include abdominal pain, nausea, vomiting, diarrhea, and liver damage. Severe cases can progress to acute liver failure, which can be life-threatening.
Due to their potent toxicity, exposure to amanitins requires immediate medical attention. There is currently no specific antidote available for amanitin poisoning. Treatment generally involves supportive measures, such as fluid replacement, medication to alleviate symptoms, and liver transplantation in severe cases.
In summary, amanitins are toxic cyclic peptides found in Amanita mushrooms that inhibit RNA polymerase II, leading to disturbances in mRNA synthesis. These compounds are responsible for the majority of the toxic effects associated with Amanita mushroom poisoning,
