Poison dart frogs, neurotoxin from

Very rapid-acting paralytic neurotoxin that binds to sodium channels of nerve and muscle cells depolarizing neurons by increasing the sodium channel permeability. It is obtained from South American poison-dart frogs (Phyllobates aurotaenia, Phyllobates terribilis). It is insoluble in water but soluble in hydrocarbons and other nonpolar solvents. The dried toxin can remain active for at least a year. However, it is relatively nonpersistent in the environment. 

Tetradotoxin is a potent neurotoxin isoiated from the ovaries and liver of many species of Tetradodontidae, especiaiiy the Japanese fugu (or puffer fish). Saxitoxin is a mussel or clam poison produced by certain marine dinoflagellates, Gonyaulax catenella or G. tamarensis, the consumption of which cause the mussels or clams to become poisonous. These poisonous shellfish were connected to a toxic red tide environmental condition on the coastal region of California in early 1970. Batrachotoxin is a cardiotoxic and neurotoxic steroid isolated originally from the poison dart frog, Phyllobates terribilis. It is a lipid soluble neurotoxin that is at least 10-fold more toxic than tetradotoxin. 

Histrionicotoxin, a paralyzing neurotoxin from certain poison dart frogs. 

Colombian poison dart frogs are tiny, beautiful, and deadly. They produce a poison called histrionicotoxin, which is an amine that causes paralysis. Death from histrionicotoxin results by suffocation through paralysis of the victim s respiratory muscles. (A molecular model of histrionicotoxin is shown above.) Curare, the Amazonian arrow poison that is a mixture of compounds from a woody vine, contains another paralytic neurotoxin, called cf-tubocu-rarine. Histrionicotoxin and d-tubocurarine both block the action of acetylcholine, an important neurotransmitter. Amines like these and others have fascinating roles in biological systems, as we shall see in this chapter while studying the properties, reactivity, and synthesis of amines. 

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