ε-Amanitin is a cyclic peptide obtained from various mushroom species. It exhibits a strong affinity for RNA polymerase II and effectively inhibits its activity.
γ-Amanitin an ADC cytotoxin and isolated from the mushroom. γ-Amanitin inhibits RNA polymerase II and disrupts synthesis of mRNA. γ-Amanitin shows similar effects to α-Amanitin and β-Amanitin.