Biologically Active Alkaloids from Poison Frogs (Dendrobatidae)

Abstract

A total of over one hundred biologically active alkaloids have been characterized in skin extracts from dendrobatid frogs. Five major classes have been defined: The highly toxic batrachotoxins are steroidal alkaloids which prevent interactivation of sodium channels in nerve and muscle. Pumiliotoxin-C class alkaloids are decahydroquinolines which block nicotinic receptor mediated neuromuscular transmission. Histrionicotoxins are spiropiperidines which block chemosensitive channels and potassium channels. The pumiliotoxin-A class alkaloids are 6-alkylidene-indolizidines which facilitate calcium-dependent excitation-contraction and excitation-secretion coupling. The gephyrotoxins are indolizidines and perhydrobenzoindolizidines. Gephyrotoxin is a muscarinic antagonist.