Toxicity of two toxins from the Florida red tide marine dinoflagellate, Ptychodiscus brevis.

The purification and crystallization of T17, a toxin from Ptychodiscus brevis, is reported. The toxicity of this compound and a second toxin known as T34 are compared by i.v., i.p. and oral administration in mice. Both toxins produce symptoms characteristic of muscarnic stimulants; hypersalivation, rhinorrhea and excessive urination and defecation being the most commonly observed. T17, which is orally toxic, is believed to be the agent responsible for Neurotoxic Shellfish Poisoning.