Colombian poison frog

Ring construction approaches have also been used effectively in the diastereoselective synthesis of the fused azepine 43 from the pyrrolidinone 41 and (Z)-l,4-dichloro-2-butene 42 [01TA2205], and in the synthesis of the alkaloid 275A (44) from the Colombian poison frog Dendrobates lehmanni [01JNP421]. 

Gephyrotoxins are unique in Nature to amphibians and, indeed, occur only in certain populations of the extremely variable Colombian poison frog, Dendrobates histrionicus (1). Gephyrotoxin might be derived by cyclization of a c/.r-decahydroquinoline having a trans orientation of the... 

A mtyor alkaloid (251F) in the small Colombian poison frog Minyabates bombetes was unusual in exhibiting a base peak at an odd mass (mh 111) in its mass spectrum (151). It was clearly unrelated to other dendrobatid alkaloids and appears to be unique to this species. The structure of alkaloid 251F has been elucidated by nuclear magnetic resonance and FTIR spectroscopy (752) it is a cyclopenta[7>]quinolizidine as shown in XI. 

Ellison earned a master of science in chemistry from the University of California, Irvine. His graduate research involved methods to synthesize poisons extracted from Colombian poison dart frogs. He has a bachelor of science in chemistry from the Georgia Institute of Technology. He is a member of the American Chemical Society and Federation of American Scientists. In addition to his works on weapons of mass destruction, he is the author of a chapter on the hazardous properties of materials in the sixth edition of the Handbook on Hazardous Materials Management, a textbook published in 2002 by the Institute of Hazardous Materials Management. 

Considerable difficulties had to be overcome in the isolation of four major highly cardiotoxic steroidal alkaloids from the skin secretions of the Colombian arrow-poison frog Phyllobates aurotaenia. The very labile pseudobatrachotoxin, whose... 

Three calycanthine-type alkaloids, (—)-calycanthine (149) (the optical antipode of (+ )-calycanthine (150)), (—)-isocalycanthine (151), and we,so-chimonanthine (152) were isolated from Psychotria forsteriana, from New Caledonia, and complete and NMR assignments were reported (101). This represents the second isolation of the levorotatory isomer of calycanthine (the first was from Pausinystalia macroceras, Rubiaceae, (102)) as well as the first isolation of we,so-chimonanthine. (—)-Calycanthine and (+ )-chimonanthine (153) were also found to occur in the skin of the Colombian poison dart frog, Phyllobates terribilis (103). 

Malassene and co-workers recently examined the application of the Thorpe-Ziegler cyclization for synthesis of perhydrohistrionicotoxin, a skin extract of the Colombian poison arrow frog, Dendrobates histrionicus. Under standard conditions, dinitrile 37 was directly converted into spiropiperidine 38 through the Thorpe-Ziegler cyclization, completing construction of the carbon framework of perhydrohistrionicotoxin. 

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. 

Recently, two indole alkaloids, calycanthine and chimonanthine, and a piperidinyldipyridine alkaloid, noranabasamine (Fig. 26) were isolated as minor compounds in extracts from the Colombian poison-dart frog... 

Daly, J., and B. Witkop Batrachotoxin, an extremely active cardio- and neurotoxin from the Colombian arrow poison frog. Clinical Toxiology 4, 331—342 (1971). 

Daly, J. W., B. Witkop, P. Bommer, and K. Biemann Batrachotoxin. The active principle of the Colombian arrow poison frog, Phyllobates bicolor. J. Amer. Chem. Soc. 87, 124—126 (1965). 

Marki, F., and B. Witkop The venom of the Colombian arrow poison frog Phyllobates bicolor. Experientia 19, 329—338 (1963). 

The Dendrobatid poison arrow frogs of Central and South America exude a potent mixture of alkaloids from their skins. It was originally thought that the frogs biosynthesized these alkaloids, but it has since been shown that they are of dietary origin. The skin exudate of the Colombian frog Minyobates bombetes causes severe locomotor difficulties, muscle spasms and convulsions upon injection in mice. The major component of the alkaloid mixture is 251F3. Jeff Aube of the University of Kansas recently described (J. Am. Chem. Soc. 2004,126,5475) the enantioselective total synthesis of 3. The key step in the synthesis was the cyclization of the keto azide 2. 

Batrachotoxin A (III), just one of many steroidal alkaloids, is one of the most lethal substances known (LD50 = 2/xg/kg subcutaneously in mice). It is found in the skin secretions of the brightly colored tropical frog Phyllobates aurotaenia and is used by Colombian Indians to prepare poison darts. 

Frog poison. Batrachotoxin (BTX) is a steroidal alkaloid from the skin of Phyllobates terribilis, a poisonous Colombian frog (source of the poison used on blowgun darts). In the presence of BTX, sodium channels in an excised patch stay persistently open when the membrane is depolarized. They close when the membrane is repolarized. Which transition is blocked by BTX ... 

Batrachotoxins. Highly poisonous "steroid alkaloids (see table) isolated from the skin of the Colombian frogs Phyllobates aurotaenia, P. terribilis, P. bicolor, P. vittatus, and P. lugubris. B. (as skin preparations) are used as arrow poisons. 

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