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Dioxin
Dioxin may refer to: * 1,2-Dioxin or 1,4-Dioxin, two unsaturated heterocyclic 6-membered rings where two carbon atoms have been replaced by oxygen atoms, giving the molecular formula C4H4O2 * Dibenzo-1,4-dioxin, the parent compound also known as dibenzodioxin or dibenzo-''p''-dioxin (molecular formula C12H8O2), in which two benzene rings are connected through two oxygen atoms * Dioxins and dioxin-like compounds, a diverse range of chemical compounds which are known to exhibit "dioxin-like" toxicity * 2,3,7,8-Tetrachlorodibenzodioxin (TCDD), the prototypical example of the above class, often referred to simply as "dioxin" See also *1,4-Dioxane, the saturated analog *Agent orange, of which TCDD is a marginal component *Digoxin * Dioxin affair, a 1999 crisis in Belgium *Seveso disaster Seveso (; lmo, label= Lombard, Séves ) is a town and '' comune'' in the Province of Monza and Brianza, in the Region of Lombardy. The economy of the town has traditionally been based on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioxins And Dioxin-like Compounds
Dioxins and dioxin-like compounds (DLCs) are a group of chemical compounds that are persistent organic pollutants (POPs) in the environment. They are mostly by-products of burning or various industrial processes - or, in case of dioxin-like PCBs and PBBs, unwanted minor components of intentionally produced mixtures. Some of them are highly toxic, but the toxicity among them varies 30,000-fold. They are grouped together because their mechanism of action is the same. They activate the aryl hydrocarbon receptor (AH receptor), albeit with very different binding affinities, leading to high differences in toxicity and other effects. They include: * Polychlorinated dibenzo''-p-''dioxins (PCDDs), or simply dioxins. PCDDs are derivatives of dibenzo''-p-''dioxin. There are 75 PCDD congeners, differing in the number and location of chlorine atoms, and 7 of them are specifically toxic, the most toxic being 2,3,7,8-tetrachlorodibenzodioxin (TCDD). * Polychlorinated dibenzofurans (PCDFs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agent Orange
Agent Orange is a chemical herbicide and defoliant, one of the "tactical use" Rainbow Herbicides. It was used by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War from 1961 to 1971. It is a mixture of equal parts of two herbicides, 2,4,5-T and 2,4-D. In addition to its damaging environmental effects, traces of dioxin (mainly TCDD, the most toxic of its type) found in the mixture have caused major health problems for many individuals who were exposed, and their offspring. Agent Orange was produced in the United States from the late 1940s and was used in industrial agriculture and was also sprayed along railroads and power lines to control undergrowth in forests. During the Vietnam War, the U.S. military procured over 20 million gallons consisting of a fifty-fifty mixture of 2,4-D and dioxin-contaminated 2,4,5-T. Nine chemical companies produced it: Dow Chemical Company, Monsanto Company, Diamond Shamrock Corporati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,3,7,8-Tetrachlorodibenzodioxin
2,3,7,8-Tetrachlorodibenzo-''p-''dioxin (TCDD) is a polychlorinated dibenzo''-p-''dioxin (sometimes shortened, though inaccurately, to simply 'dioxin')Tuomisto, Jouko (2019) Dioxins and dioxin-like compounds: toxicity in humans and animals, sources, and behaviour in the environment. WikiJournal of Medicine 6(1): 8 , https://doi.org/10.15347/wjm/2019.008 with the chemical formula CHClO. Pure TCDD is a colorless solid with no distinguishable odor at room temperature. It is usually formed as an unwanted product in burning processes of organic materials or as a side product in organic synthesis. TCDD is the most potent compound ( congener) of its series (polychlorinated dibenzodioxins, known as PCDDs or simply dioxins) and became known as a contaminant in Agent Orange, a herbicide used in the Vietnam War. TCDD was released into the environment in the Seveso disaster. It is a persistent organic pollutant. Mechanism of action TCDD and dioxin-like compounds act via a specific re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dibenzo-1,4-dioxin
Dibenzo-1,4-dioxin, also dibenzodioxin or dibenzo-''p''-dioxin (dibenzo-''para''-dioxin), is a polycyclic heterocyclic organic compound in which two benzene rings are connected by a 1,4-dioxin ring. Its molecular formula is C12H8O2. The two oxygen atoms occupy opposite ( ''para''-) positions in the six-membered dioxin ring. Dibenzodioxin is the carbon skeleton of the poisonous polychlorinated dibenzodioxins (PCDDs), often called dioxins. The most harmful PCDD is 2,3,7,8-tetrachlorodibenzodioxin (TCDD). Dioxins and dioxin-like compounds is a category of pollutants that includes PCDDs and other compounds that have similar structure, toxicity, and persistence. Dibenzodioxin is also the skeleton of the polybrominated dibenzodioxins. Isomer The general name dibenzodioxin usually refers to dibenzo-''p''-dioxin. The isomeric compound dibenzo-''o''-dioxin (dibenzo-''ortho''-dioxin) or dibenzo-1,2-dioxin, like the unstable 1,2-dioxin, has two adjacent oxygen atoms ( ''ortho''-). No de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,4-Dioxin
1,4-Dioxin (also referred as dioxin or ''p''-dioxin) is a heterocyclic, organic, non-aromatic compound with the chemical formula CHO. There is an isomeric form of 1,4-dioxin, 1,2-dioxin (or ''o''-dioxin). 1,2-Dioxin is very unstable due to its peroxide-like characteristics. The term "dioxin" is most commonly used for a family of derivatives of dioxin, known as polychlorinated dibenzodioxins (PCDDs). Preparation 1,4-Dioxin can be prepared by cycloaddition, namely by the Diels–Alder reaction of furan and maleic anhydride. The adduct formed has a carbon-carbon double bond, which is converted to an epoxide. The epoxide then undergoes a retro-Diels–Alder reaction, forming 1,4-dioxin and regenerating maleic anhydride. Derivatives The word "dioxin" can refer in a general way to compounds which have a dioxin core skeletal structure with substituent molecular groups attached to it. For example, dibenzo-1,4-dioxin is a compound whose structure consists of two benzo- groups fused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Dioxin
1,2-Dioxin is a heterocyclic, organic, antiaromatic compound with the chemical formula CHO. It is an isomeric form of 1,4-dioxin (or ''p''-dioxin). Due to its peroxide-like characteristics, 1,2-dioxin is very unstable and has not been isolated. Calculations suggest that it would isomerize rapidly into but-2-enedial. Even substituted A substitution reaction (also known as single displacement reaction or single substitution reaction) is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group. Substitution reactions ar ... derivatives are very labile, e.g. 1,4-diphenyl-2,3-benzodioxin. Indeed, in 1990, 3,6-bis(''p''-tolyl)-1,2-dioxin was wrongly accounted as the first stable derivative. It was subsequently shown that the initial compound was not a derivative of 1,2-dioxin, but a thermodynamically more stable dione. File:Dioxin isomers.svg, The isomers 1,2-dioxin (left) and 1,4-dioxin (right) File:1,4-diphenyl-2,3-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seveso Disaster
Seveso (; lmo, label= Lombard, Séves ) is a town and '' comune'' in the Province of Monza and Brianza, in the Region of Lombardy. The economy of the town has traditionally been based on the furniture industry. Its name comes from the river of the same name which crosses the '' comune'' in a north-south direction. Seveso received the honorary title of city with a presidential decree on 18 June 2003. Geography The town is situated to the north of Milan in the Brianza lowlands. The territory of the commume is highly urbanised, with the majority of inhabitants living in the town. Seveso lies on the national trunk road ''Statale dei Giovi'', which connects Milan to Como and on the Milan-Meda motorway. Seveso railway station is located on the Milan–Asso railway, while Seveso-Baruccana railway station is located on the Saronno–Seregno railway. Neighbouring communes are Meda, Seregno, Barlassina, Cogliate, Cesano Maderno. History Seveso's origins date back to about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxin
Digoxin (better known as Digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the contraction. Digoxin is taken by mouth or by injection into a vein. Digoxin has a half life of approximately 36 hours given at average doses in patients with normal renal function. It is excreted mostly unchanged in the urine. Common side effects include breast enlargement with other side effects generally due to an excessive dose. These side effects may include loss of appetite, nausea, trouble seeing, confusion, and an irregular heartbeat. Greater care is required in older people and those with poor kidney function. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called '' empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of atoms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parent Compound
In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized. Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one or no functional groups and often have various types of symmetry. Benzene () is a chemical itself consisting of a hexagonal ring of carbon atoms with a hydrogen atom attached to each, and is the parent of many derivatives that have substituent atoms or groups replacing one or more of the hydrogens. Some parents are rare or nonexistent themselves, as in the case of porphine, though many simple and complex derivatives are known. File:Benzene circle.png, Benzene is the parent. File:Toluene-vec.svg, Toluene is a derivative of benzene. File:Porphyrin.svg, Porphine is the parent of porphyrins. File:PPIXtransH.png, Protoporphyrin IX is a natural derivative of the parent porphine. File:H2octaethylporphyrin.png , Octaethylporphyrin is a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" (benz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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