Sanguinarine is a toxic quaternary ammonium salt from the group of benzylisoquinoline alkaloids. It is extracted from some plants, including bloodroot (Sanguinaria canadensis), Mexican prickly poppy Argemone mexicana, Chelidonium majus and Macleaya cordata. It is also found in the root, stem and leaves of the opium poppy but not in the capsule. Sanguinarine is a toxin that kills animal cells through its action on the Na+-K+-ATPase transmembrane protein.[2] Epidemic dropsy is a disease that results from ingesting sanguinarine. If applied to the skin, sanguinarine kills cells and may destroy tissue. In turn, the bleeding wound may produce a massive scab, called an eschar. For this reason, sanguinarine is termed an escharotic. In plants, sanguinarine is synthesized from dihydrosanguinarine through the action of Dihydrobenzophenanthridine oxidase (EC 1.5.3.12).