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Pumiliotoxin
Pumiliotoxins (PTXs), are one of several toxins found in the skin of poison dart frogs. The frog species, 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 very poisonous in high concentrations. Pumiliotoxins are much weaker than batrachotoxins, ranging between 100 and 1000 times less poisonous. There are three different types of this toxin: A, B and C, of which toxins A and B are more toxic than C. Pumiliotoxins interfere with muscle contraction by affecting calcium channels, causing partial paralysis, difficulty moving, hyperactivity, or death. The median lethal dose of pumiliotoxins A and B is 50 µg / mouse, 20 µg / mouse respectively, while the amount of pumiliotoxin is 200 µg / frog.http://wiredspace.wits.ac.za/bitstream/handle/1053 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumiliotoxin AB
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 very poisonous in high concentrations. Pumiliotoxins are much weaker than batrachotoxins, ranging between 100 and 1000 times less poisonous. There are three different types of this toxin: A, B and C, of which toxins A and B are more toxic than C. Pumiliotoxins interfere with muscle contraction by affecting calcium channels, causing partial paralysis, difficulty moving, hyperactivity, or death. The median lethal dose of pumiliotoxins A and B is 50 µg / mouse, 20 µg / mouse respectively, while the amount of pumiliotoxin is 200 µg / frog.http://wiredspace.wits.ac.za/bitstre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumiliotoxin251D
Pumiliotoxins (PTXs), are one of several toxins found in the skin of poison dart frogs. The frog species, 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 very poisonous in high concentrations. Pumiliotoxins are much weaker than batrachotoxins, ranging between 100 and 1000 times less poisonous. There are three different types of this toxin: A, B and C, of which toxins A and B are more toxic than C. Pumiliotoxins interfere with muscle contraction by affecting calcium channels, causing partial paralysis, difficulty moving, hyperactivity, or death. The median lethal dose of pumiliotoxins A and B is 50 µg / mouse, 20 µg / mouse respectively, while the amount of pumiliotoxin is 200 µg / frog.http://wiredspace.wits.ac.za/bitstream/handle/1053 ... [...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 pumili ... [...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 pumili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bibron's Toadlet
The 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'' ... [...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 frog, ... [...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, while others have cryptic coloration with minimal to no amount of observed toxicity. The species that have great toxicity derive this feature from their diet of ants, mites and termites. However, other species that exhibit cryptic coloration, and low to no amounts of toxicity, eat a much larger variety of prey. 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 Native Americans' use of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrolizidine Alkaloid
Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores. More than 660 PAs and PA N-oxides have been identified in over 6,000 plants, and about half of them exhibit hepatotoxicity. They are found frequently in plants in the Boraginaceae, Asteraceae, Orchidaceae and Fabaceae families; less frequently in the Convolvulaceae and Poaceae, and in at least one species in the Lamiaceae. It has been estimated that 3% of the world’s flowering plants contain pyrrolizidine alkaloids. Honey can contain pyrrolizidine alkaloids, as can grains, milk, offal and eggs. To date (2011), there is no international regulation of PAs in food, unlike those for herbs and medicines. Unsaturated pyrrolizidine alkaloids are hepatotoxic, that is, damaging to the liver. PAs also cause hepatic veno-occlusive disea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batrachotoxin
Batrachotoxin (BTX) is an extremely potent cardio- and neurotoxic steroidal alkaloid found in certain species of beetles, birds, and frogs. The name is from the Greek word grc, βάτραχος, bátrachos, frog, label=none. Structurally-related chemical compounds are often referred to collectively as batrachotoxins. It is an extremely poisonous alkaloid. In certain frogs, this alkaloid is present mostly on the skin. Such frogs are among those used for poisoning darts. Batrachotoxin binds to and irreversibly opens the sodium channels of nerve cells and prevents them from closing, resulting in paralysis and death. No antidote is known. History Batrachotoxin was discovered by Fritz Märki and Bernhard Witkop, at the National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland, U.S.A. Märki and Witkop separated the potent toxic alkaloids fraction from ''Phyllobates bicolor'' and determined its chemical properties in 1963. They isolat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
