Histrionicotoxins: roentgen-ray analysis of the novel allenic and acetylenie spiroalkaloids isolated from a Colombian frog, Dendrobates histrionicus.
The structures and absolute configuration of two unique alkaloids isolated from the Colombian frog, Dendrobates histrionicus, have been elucidated by Roentgen-ray (x-ray) crystallography. Histrionicotoxin is (2pR, 6S, 7pS, 8aS)-7-(cis-1-buten-3-ynyl)-8-hydroxy-2-(cis-2-penten-4- ynyl)-1-azaspiro[5.5] undecane, while in dihydro-isohistrionicotoxin the acetylenic 2-pentenynyl side chain is replaced by an allenic 2-(3,4 pentadienyl) substituent. Dendrobates histrionicus exhibits remarkable interpopulational variations in amounts and composition of skin toxins, in behavior, and in phenotypic characters, aspects of which are illustrated in a color plate. The histrionico-toxins are the third class of alkaloids isolated from the defensive skin secretions of Neotropical (Dendrobatidae) frogs.
D000470:Alkaloids / Q000302:isolation & purification*; D000818:Animals; D001001:Anura / Q000032:analysis*; D002845:Chromatography; D003116:Color; D008961:Models, Structural; D008970:Molecular Weight; D010641:Phenotype; D012867:Skin / Q000032:analysis*; D014118:Toxins, Biological / Q000302:isolation & purification*; D014961:X-Ray Diffraction
D000470:Alkaloids; D014118:Toxins, Biological