Epsilon-Amanitin

"epsilon"-Amanitin or ε-amanitin is a cyclic peptide. It is an amatoxin, all of which are found in several members of the mushroom genus "Amanita". The oral of ε-amanitin is approximately 0.1 mg/kg.
Toxicology.
Like other amatoxins, ε-amanitin is an inhibitor of RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme which completely prevents mRNA synthesis, effectively causing cytolysis of hepatocytes (liver cells) and kidney cells.