Top 10 World's Deadliest Poisons
Posted by Ivica Miskovic in Bizarre, Health, Science
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.
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
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).
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