Ε-Amanitinε-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.ToxicologyLike 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 and kidney cells.