Proamanullin

Promanullin is a cyclic nonribosomal peptide. It is an amatoxin, all of which are found in the mushroom genus Amanita.

Toxicology

Like other amatoxins, proamanullin is an inhibitor of RNA [polymerase II]. Promanullin has a specific attraction to the enzyme RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme, effectively causing cytolysis of hepatocytes.