Histrionicotoxin

I read this information from Organic Chemistry. Histrionicotoxin is a diyne isolated in small quantities from the skin of Dendrobates histrionicus, a colorful South American frog. This toxin, secreted by the frog as a natural defense mechanism, was used as a poison on arrow tips by the Choco tribe of South America. These small “poison dart” frogs inhabit the moist humid floor of tropical rainforests, and are commonly found in western Ecuador and Colombia. Histrionicotoxin acts by interfering with nerve transmission in mammals, resulting in prolonged muscle contraction.