palytoxin

[păl′ə-tŏk′sĭn]

An extremely powerful toxin occurring in corals of the genus Palythoa of the South Pacific. Palytoxin disrupts the flow of ions across cell membranes and is the most potent known naturally occurring poison, being rapidly fatal to humans in doses of 4 micrograms. One of the most complex known nonprotein substances, it has more contiguous carbon atoms (115) than any other naturally occurring molecule. Chemical formula: C129H223N3O54.