Monday, November 10, 2008

Top 10 World's Deadliest Poisons

10. Sodium fluoroacetate (Compound 1080)
Sodium fluoroacetate (also known as sodium monofluoroacetate, compound 1080 or 1080) is a potent metabolic poison that occurs naturally as an anti-herbivore metabolite in various plants. It works by interfering with the citric acid cycle, and is used primarily to control mammalian pests, including invasive species. The existence of this chemical was first noted in the Second World War.
Sodium fluoroacetate is used as a rodenticide. Farmers and graziers use the poison to protect pastures and crops from various herbivorous mammals. It is used in New Zealand to control the Common Brushtail Possum , while in the United States it is used to kill coyotes. Other countries using 1080 include Australia, Mexico and Israel. Western Shield is a recent project to boost populations of endangered mammals in south-west Australia. The project is to drop Sodium fluoroacetate baited meat from helicopters or light aircraft to kill predators. Wild dogs and foxes will readily eat the baited meat. Cats pose a greater difficulty as cats aren’t interested in already dead animals. Recently a pilot tried putting small sound generators inside the baits with significant positive results. However, an Australian RSPCA commissioned study criticized 1080 calling it an inhumane killer.

9. Amatoxin
Amatoxins are a subgroup of at least eight toxic compounds found in several genera of poisonous mushrooms, most notably Amanita phalloides and several other members of the genus Amanita, as well as some Conocybe, Galerina and Lepiota mushroom species.
The compounds have a similar structure, that of eight amino-acid rings; they were isolated in 1941 by Heinrich O. Wieland and Rudolf Hallermayer of the University of Munich. Of the amatoxins, α-amanitin is the chief component and along with β-amanitin is likely responsible for the toxic effects. Their major toxic mechanism is the inhibition of RNA polymerase II, a vital enzyme in the synthesis of messenger RNA (mRNA), microRNA, and small nuclear RNA (snRNA). Without mRNA, essential protein synthesis, and hence cell metabolism, grind to a halt and the cell dies. The liver is the principal organ affected, as it is the organ which is first encountered after absorption in the gastrointestinal tract, though other organs, especially the kidneys, are susceptible. The RNA polymerase of Amanita phalloides is insensitive to the effects of amatoxins; as such, the mushroom does not poison itself.
Their swift intestinal absorption coupled with their thermostability explains why their toxic effects occur in a relatively short period of time. The most severe effects are toxic hepatitis with centrolobular necrosis and hepatic steatosis, as well as acute tubulointerstitial nephropathy, which altogether induce a severe hepatorenal syndrome (with a potentially fatal outcome). The estimated minimum lethal dose is 0.1 mg/kg or 7 mg of toxin in adults.

8. Strychnine
Strychnine is a very toxic (LD50 = 10 mg approx.), colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine causes muscular convulsions and eventually death through asphyxia or sheer exhaustion. The most common source is from the seeds of the Strychnos nux vomica tree. Strychnine is one of the most bitter substances known. Its taste is detectable in concentrations as low as 1 ppm.
Strychnine acts as a blocker or antagonist at the inhibitory or strychnine-sensitive glycine receptor (GlyR), a ligand-gated chloride channel in the spinal cord and the brain.
Although it is best known as a poison, small doses of strychnine were once used in medications as a stimulant, a laxative and as a treatment for other stomach ailments. A 1934 drug guide for nurses described it as "among the most valuable and widely prescribed drugs". Strychnine's stimulant effects also led to its use historically for enhancing performance in sports. Because of its high toxicity and tendency to cause convulsions, the use of strychnine in medicine was eventually abandoned once safer alternatives became available.
The dosage for medical use was cited as between "1/60th grain–1/10th grain", which is between 1.1 milligrams and 6.4 milligrams in modern measures. Normally the maximum dosage used was 3.2 mg, half of a "full dose". A lethal dose was cited as 1/2 a grain (32 mg), but people have been known to die from as little as 5 mg of strychnine.

7. Mercury
Mercury , also called quicksilver or hydrargyrum, is a chemical element with the symbol Hg (Latinized Greek: hydrargyrum, meaning watery or liquid silver) and atomic number 80. A heavy, silvery d-block metal, mercury is one of five metals that are liquid at or near room temperature and pressure. The others are the metals caesium, francium, gallium, and rubidium, as well as the non-metalbromine. Of these, only mercury and bromine are liquids at standard conditions for temperature and pressure.
Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, and other scientific apparatus, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favour of alcohol-filled, digital, or thermistor-based instruments. It remains in use in a number of other ways in scientific and scientific research applications, and in amalgam material for dental restoration. Mercury is mostly obtained by reduction from the mineral cinnabar.
Mercury occurs in deposits throughout the world and it is harmless in an insoluble form, such as mercuric sulfide, but it is poisonous in soluble forms such as mercuric chloride or methylmercury.

6. Cyanide
A cyanide is any chemical compound that contains the cyano group (C≡N), which consists of a carbon atom triple-bonded to a nitrogen atom. In salts and solution cyanide is generally the anion CN-. Many organic compounds feature cyanide as a functional group. These are called nitriles in IUPAC nomenclature (for example, CH3CN is referred to by the names acetonitrile or ethanenitrile per IUPAC, but occasionally it is labeled using the common name methyl cyanide). The Cyanide molecule, CN, also known as the Cyano radical, is commonly produced in reactions and has been identified in interstellar space . Of the many kinds of cyanide compounds, some are gases, others are solids or liquids. Those that can release the cyanide ion CN- are highly toxic.

5. Tetrodotoxin
Tetrodotoxin (anhydrotetrodotoxin 4-epitetrodotoxin, tetrodonic acid, TTX) is a potent neurotoxin with no known antidote, which blocks action potentials in nerves by binding to the pores of the voltage-gated, fast sodium channels in nerve cell membranes. The binding site of this toxin is located at the pore opening of the voltage-gated Na+ channel. Its name derives from Tetraodontiformes, the name of the order that includes the pufferfish, porcupinefish, ocean sunfish or mola, and triggerfish, several species of which carry the toxin. Although tetrodotoxin was discovered in these fish and found in several other animals (e.g., Blue-ringed Octopus, Rough-skinned newt), it is actually the product of certain bacteria such as Pseudoalteromonas tetraodonis, certain species of Pseudomonas and Vibrio, as well as some others.
Its mechanism was discovered in the early 1960s by Toshio Narahashi working at Duke University.

4. Sarin
Sarin, also known by its NATO designation of GB, is an extremely toxic substance whose sole application is as a nerve agent. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations in UN Resolution 687. Production and stockpiling of sarin was outlawed by the Chemical Weapons Convention of 1993.

3. Anthrax
Anthrax toxin refers to three proteins secreted by virulent strains of the bacterium Bacillus anthracis. These three proteins act together in a synergistic way in which they are endocytosed and translocated into the cytoplasm of a macrophage, where it disrupts cellular signaling and induces cell death, allowing the bacteria to evade the immune system.
The disease known as anthrax is caused by Bacillus anthracis, a spore-forming bacterium whose pathogenesis is primarily the result of a tripartite toxin. This toxin is composed of three proteins: the protective antigen (PA), the edema factor (EF) and the lethal factor (LF). These proteins work together to enter a cell and disrupt the signaling pathways, eventually leading to apoptosis. The molecular actions of PA, EF, and LF also provide a model biochemical system that demonstrates a variety of structure-function relationships seen in biochemistry.

2. Ricin
Ricin is a protein toxin that is extracted from the castor bean (Ricinus communis).
The U.S. Centers for Disease Control (CDC) gives a possible minimum figure of 500 micrograms (about the size of a grain of salt) for the lethal dose of ricin in humans if exposure is from injection or inhalation.

1. Botulinum
Botulinum toxin is a neurotoxin protein produced by the bacterium Clostridium botulinum. It is one of the most poisonous naturally occurring substances, and it is the most toxic protein. Though it is highly toxic, it is used in minute doses both to treat painful muscle spasms, and as a cosmetic treatment in some parts of the world. It is sold commercially under the brand names Botox, Dysport, and Myobloc for this purpose. The terms Botox, Dysport, and Myobloc are trade names and are not used generically to describe the neurotoxins produced by C. botulinum.
credited to wikipedia

Posted by Ivica Miskovic

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