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Pumiliotoxin
Pumiliotoxins (PTXs), are one of several toxins found in the skin of poison dart frogs. The frog species, Bibron's toadlet, P. bibronii also produces PTXs to deter predators. Closely related, though more toxic, are allopumiliotoxins, (aPTXs). Other toxins found in the skin of poison frogs include decahydroquinolines (DHQs), izidines, coccinellines, and spiropyrrolizidine alkaloids. Pumiliotoxins are poisonous in high concentrations. Pumiliotoxins are much weaker than batrachotoxins, ranging between 100 and 1000 times less poisonous. Structure The different divisions of compounds in the pumiliotoxin-A class arise from differences in the carbon backbone and/or the substituents attached to it. The difference between allopumiliotoxins and pumiliotoxins occurs at the 7 position. At this position, pumiliotoxins have a hydrogen whereas allopumiliotoxins have a hydroxyl substituent. Both have methyl and hydroxyl groups at the C-8 position. Homopumiliotoxins contain a quinolizidine ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopumiliotoxin
Allopumiliotoxins are a structural division in the pumiliotoxin-A class of alkaloids. The compounds of the pumiliotoxin-A class are primarily found in the skins of frogs, toads, and other amphibians and are used as a chemical defense mechanism to ward off predators, microorganisms, and ectoparasites. The compounds were originally discovered in neotropical dendrobatid frogs, but are also found in the mantellid frogs of Madagascar, myobatrachid frogs of Australia, and bufonid toad of South America. Frogs possessing this defense mechanism have aposematic coloring.Jain, P.; Garraffo, H. M.; Spande, T. F.; Yeh, H. J. C.; Daly, J. W. J. Nat. Prod. 1995, 58, 100-104. Biological activity The poison-dart frog family Dendrobatidae has yielded many different alkaloids categorized into several different classes, almost all of which have shown high pharmacological activity on muscle and nerve cells.Aoyagi, S.; Wang, T. C.; Kibayashi, C. J. Am. Chem. Soc. 1993, 115, 11393-11409. The pumil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumiliotoxin 251D
Pumiliotoxin 251D is a toxic organic compound. It is found in the skin of poison frogs from the genera '' Dendrobates'', ''Epipedobates'', '' Minyobates'', and ''Phyllobates'' and toads from the genus '' Melanophryniscus''. Its name comes from the pumiliotoxin family (PTXs) and its molecular mass of 251 daltons. When the toxin enters the bloodstream through cuts in the skin or by ingestion, it can cause hyperactivity, convulsions, cardiac arrest and ultimately death. It is especially toxic to arthropods (e.g. mosquitoes), even at low (naturally occurring) concentrations. Chemical properties Structure The chiral centers in pumiliotoxin 251D can give several stereoisomers of the compound. Only one form of the toxin is present in nature and has toxic properties. Two enantiomers of pumiliotoxin 251D. On the left the plus enantiomer is shown which is toxic. On the right side the minus enantiomer, which is not toxic, is shown. The side chain conformation of substituents at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indolizidine Alkaloids
Indolizidine alkaloids are natural products from various alkaloid groups whose structure can be derived from indolizidine. Occurrence Indolizidine alkaloids are present in various plant families, including Elaeocarpaceae, Asclepiadaceae, and are also produced as metabolites by fungi and bacteria. For instance, Slaframine and swainsonine were identified in the fungus '' Rhizoctonia leguminicola'', while Castanospermine was extracted from Castanospermum australe. Notably, this alkaloid group includes pumiliotoxins, which are the toxins of the ''strawberry poison-dart frog''. Representatives Polyhydroxy alkaloids The polyhydroxy alkaloids include compounds like castanospermine and swainsonine. (+)-Castanospermine Structural Formula V1.svg, (+)-Castanospermine (-)-Swainsonine Structural Formula V2.svg, (-)-Swainsonine Pumiliotoxins The primary alkaloids within the pumiliotoxin category are pumiliotoxin A and pumiliotoxin B. Other representatives include gephyrotoxin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poison Dart Frog
Poison dart frog (also known as dart-poison frog, poison frog or formerly known as poison arrow frog) is the common name of a group of frogs in the family Dendrobatidae which are native to tropical Central and South America. These species are diurnal and often have brightly colored bodies. This bright coloration is correlated with the toxicity of the species, making them aposematic. Some species of the family Dendrobatidae exhibit extremely bright coloration along with high toxicity — a feature derived from their diet of ants, mites and termites— while species which eat a much larger variety of prey have cryptic coloration with minimal to no amount of observed toxicity. Many species of this family are threatened due to human infrastructure encroaching on their habitats. These amphibians are often called "dart frogs" due to the aboriginal South Americans' use of their toxic secretions to poison the tips of blowdarts. However, out of over 170 species, only four have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bibron's Toadlet
Bibron's toadlet or brown toadlet (''Pseudophryne bibronii'') is a species of Australian ground-dwelling frog that, although having declined over much of its range, is widespread through most of New South Wales, Victoria, south-eastern Queensland, and eastern South Australia, including Kangaroo Island. Bibron's toadlet settles in a wide variety of habitats within these region but they mainly reside in dry forests, woodland, shrubland, grassland, coastal swamps, heathland, and sub-alpine areas. They deposit their eggs in leaf litters during the flooding season, which is essential for the proper development of the egg. This species has high sexual dimorphism within the species and utilizes chemosignals to attract potential mates. Taxonomy The genus '' Pseudophryne'' encapsulates 14 different species of frogs localized to Australia. These frogs are morphologically similar to small bufonid frogs not localized to Australia. The first known nomenclature of the ''Pseudophryne'' genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indolizidine
Indolizidine is a heterocyclic chemical compound that forms the central core of the indolizidine alkaloids such as swainsonine and castanospermine. See also * Indole * Indolizine * Tryptophan * Tryptamine Tryptamine is an indolamine metabolite of the essential amino acid tryptophan. The chemical structure is defined by an indole—a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the firs ... References Indolizidines {{heterocyclic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histrionicotoxin
Histrionicotoxins are a group of related toxins found in the skin of poison frogs from the family Dendrobatidae, notably '' Oophaga histrionica'' (formerly ''Dendrobates histrionicus''), which are native to Colombia. It is likely that, as with other poison frog alkaloids, histrionicotoxins are not manufactured by the amphibians, but absorbed from insects in their diet and stored in glands in their skin. They are notably less toxic than other alkaloids found in poison frogs, yet their distinct structure acts as a neurotoxin by non-competitive inhibition of nicotinic acetylcholine receptors. History The first record of histrionicotoxins dates to 1823 by Captain Charles Stuart Cochrane. Cochrane was exploring the tropical rainforests around Colombia and Panama. His reports mention tribes of Indians who used poison tipped arrows and blowgun darts for hunting and war. Upon further exploration, Cochrane found that these Indians extracted the poison from the skins of the poison dart fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
