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Methyl Fluoroacetate
Methyl fluoroacetate (MFA) is an extremely toxic methyl ester of fluoroacetic acid. It is a colorless, odorless liquid at room temperature. It is used as a laboratory chemical and as a rodenticide. Because of its extreme toxicity, MFA was studied for potential use as a chemical weapon. The general population is not likely to be exposed to methyl fluoroacetate. People who use MFA for work, however, can breathe in or have direct skin contact with the substance.National Center for Biotechnology Information. PubChem Database. Methyl fluoroacetate, CID=9959, https://pubchem.ncbi.nlm.nih.gov/compound/Methyl-fluoroacetate (accessed on Mar. 20, 2020) History MFA was first synthesized in 1896 by the Belgian chemist Swart by reacting methyl iodoacetate with silver fluoride. It can also be synthesized by reacting methyl chloroacetate with potassium fluoride Because of its toxicity, MFA was studied for potential use as a chemical weapon during World War II. It was considered a good water po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoroacetic Acid
Fluoroacetic acid is a organofluorine compound with formula CH2FCO2H. It is a colorless solid that is noted for its relatively high toxicity. The conjugate base, fluoroacetate occurs naturally in at least 40 plants in Australia, Brazil, and Africa. It is one of only five known organic fluorine-containing natural products. Toxicity Fluoroacetic acid is a harmful metabolite of some fluorine-containing drugs (median lethal dose, LD50 = 10 mg/kg in humans). The most common metabolic sources of fluoroacetic acid are fluoroamines and fluoroethers. Fluoroacetic acid can disrupt the Krebs cycle. In contrast with monofluoroacetic acid, difluoroacetic acid and trifluoroacetic acid are far less toxic. Its pKa is 2.66, in contrast to 1.24 and 0.23 for the respective di- and trifluorinated acids. Uses Fluoroacetic acid is used to manufacture pesticides especially rodenticides (see sodium fluoroacetate Sodium fluoroacetate is an organofluorine chemical compound with the formula FCH2CO2Na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoroacetate
Fluoroacetate may refer to: * Fluoroacetic acid * Sodium fluoroacetate Sodium fluoroacetate is an organofluorine chemical compound with the formula FCH2CO2Na. This colourless salt has a taste similar to that of sodium chloride and is used as a rodenticide. History and production The effectiveness of sodium fluoroa ... {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromophores
A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore is a region in the molecule where the energy difference between two separate molecular orbitals falls within the range of the visible spectrum. Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change in the molecule when hit by light. Conjugated pi-bond system chromophores Just like how two adjacent p-orbitals in a molecule will form a pi-bond, three or more adjacent p-orbitals in a molecule can form a conjugated pi-system. In a conjugated pi-system, electrons are able to capture certain photons as the electrons resonate along a certain distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asphyxia
Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can induce asphyxia, all of which are characterized by the inability of a person to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death. In 2015, about 9.8 million cases of unintentional suffocation occurred which resulted in 35,600 deaths. The word asphyxia is from Ancient Greek "without" and , "squeeze" (throb of heart). Causes Situations that can cause asphyxia include but are not limited to: airway obstruction, the constriction or obstruction of airways, such as from asthma, laryngospasm, or simple blockage from the presence of foreign materials; from being in environments where oxygen is not readily accessible: such as underwater, in a low oxygen atmosphere, or in a vacuum; envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picrotoxin
Picrotoxin, also known as cocculin, is a poisonous crystalline plant compound. It was first isolated by the French pharmacist and chemist Pierre François Guillaume Boullay (1777–1869) in 1812. The name "picrotoxin" is a combination of the Greek words "picros" (bitter) and "toxicon" (poison). A mixture of two different compounds, picrotoxin occurs naturally in the fruit of the ''Anamirta cocculus'' plant, although it can also be synthesized chemically. Due to its interactions with the inhibitory neurotransmitter GABA, picrotoxin acts as a stimulant and convulsant. It mainly impacts the central nervous system, causing seizures and respiratory paralysis in high enough doses. Chemical structure and synthesis Picrotoxin is an equi molar mixture of two compounds, picrotoxinin (C15H16O6; CAS# 17617-45-7) and picrotin (C15H18O7; CAS# 21416-53-5). Of the two compounds, picrotin is less active. Picrotoxin occurs naturally in the fruit of the ''Anamirta cocculus'', a climbing plant fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptazol
Pentylenetetrazol, also known as pentylenetetrazole, leptazol, metrazol, pentetrazol (INN), pentamethylenetetrazol, Corazol, Cardiazol, Deumacard, or PTZ, is a drug formerly used as a circulatory and respiratory stimulant. High doses cause convulsions, as discovered by Hungarian-American neurologist and psychiatrist Ladislas J. Meduna in 1934. It has been used in convulsive therapy, and was found to be effective—primarily for depression—but side effects such as uncontrolled seizures were difficult to avoid. In 1939, pentylenetetrazol was replaced by electroconvulsive therapy, which is easier to administer, as the preferred method for inducing seizures in England's mental hospitals. In the US, its approval by the Food and Drug Administration was revoked in 1982. It is used in Italy as a cardio-respiratory stimulant in combination with codeine in a cough suppressant drug. Mechanism The mechanism of pentylenetetrazol is not well understood, and it may have multiple mechanisms o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strychnine
Strychnine (, , US chiefly ) is a highly toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eyes or mouth, causes poisoning which results in muscular convulsions and eventually death through asphyxia. While it is no longer used medicinally, it was used historically in small doses to strengthen muscle contractions, such as a heart and bowel stimulant and performance-enhancing drug. The most common source is from the seeds of the ''Strychnos nux-vomica'' tree. Biosynthesis Strychnine is a terpene indole alkaloid belonging to the ''Strychnos'' family of '' Corynanthe'' alkaloids, and it is derived from tryptamine and secologanin. The biosynthesis of strychine was solved in 2022. The enzyme, strictosidine synthase, catalyzes the condensation of tryptamine and secologanin, followed by a Pictet-Spengler reaction to form strictosidine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotine
Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits (nAChRα9 and nAChRα10) where it acts as a receptor antagonist. Nicotine constitutes approximately 0.6–3.0% of the dry weight of tobacco. Nicotine is also present at ppb-concentrations in edible plants in the family Solanaceae, including potatoes, tomatoes, and eggplants, though sources disagree on whether this has any biological significance to human consumers. It functions as an antiherbivore toxin; consequently, nicotine was widely used as an insecticide in the past, and neonicotinoids (structurally similar to nicotine), such as imidacloprid, are s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LD50
In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of increased toxicity. The test was created by J.W. Trevan in 1927. The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug Botox without animal tests. Conventions The LD50 is usually expressed as the mass of substance administered per unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Failure
Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate, abnormal blood gases (hypoxemia, hypercapnia, or both), and evidence of increased work of breathing. Respiratory failure causes an altered mental status due to ischemia in the brain. The typical partial pressure reference values are oxygen Pa more than 80 mmHg (11 kPa) and carbon dioxide Pa less than 45 mmHg (6.0 kPa). Cause Several types of conditions can potentially result in respiratory failure: * Conditions that reduce the fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convulsion
A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a synonym for ''seizure''. However, not all epileptic seizures lead to convulsions, and not all convulsions are caused by epileptic seizures. Convulsions are also consistent with an electric shock and improper enriched air scuba diving. Non-epileptic convulsions have no relation with epilepsy, and are caused by non-epileptic seizures. Convulsion is a common term generally describing uncontrollable muscle contractions. The term convulsion has been used interchangeably with the word "seizure". Seizures may cause a person to have convulsions, but this is not always the case. Convulsion is a type of seizure that involves bursts of electrical activity in the brain. Occasionally the reason for a convulsion is unfamiliar. A convulsion may be caused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convulsant
A convulsant is a drug which induces convulsions and/or epileptic seizures, the opposite of an anticonvulsant. These drugs generally act as stimulants at low doses, but are not used for this purpose due to the risk of convulsions and consequent excitotoxicity. Most convulsants are antagonists (or inverse agonists) at either the GABAA or glycine receptors, or ionotropic glutamate receptor agonists. Many other drugs may cause convulsions as a side effect at high doses (e.g. bupropion, tramadol, pethidine, dextropropoxyphene, clomipramine) but only drugs whose primary action is to cause convulsions are known as convulsants. Nerve agents such as sarin, which were developed as chemical weapons, produce convulsions as a major part of their toxidrome, but also produce a number of other effects in the body and are usually classified separately. Dieldrin which was developed as an insecticide blocks chloride influx into the neurons causing hyperexcitability of the CNS and convulsions. The I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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