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S-oxide
In organosulfur chemistry, S-oxide may refer to: * S-oxides of disulfides, compounds with the linkage RSS(O)R. Several 1,2-dithiolanes form S-oxides. * S-oxides of thioketones and thioaldehydes, compounds with the formula R2C=S=O and RCH=S=O, respectively. syn-Propanethial-S-oxide, a lacrymatory component of onion, is one example. * sulfoxides, compounds with the formula R2SO, are sometimes referred to as S-oxides. Methionine-S-oxide reductase illustrates this nomenclature. Sulfur oxide refers to inorganic compounds with the formula SOx, especially sulfur dioxide and sulfur trioxide Sulfur trioxide (alternative spelling sulphur trioxide) is the chemical compound with the formula SO3. It has been described as "unquestionably the most conomicallyimportant sulfur oxide". It is prepared on an industrial scale as a precursor to .... References {{Reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methionine-S-oxide Reductase
Methionine-S-oxide reductase (, ''methyl sulfoxide reductase I and II'', ''acetylmethionine sulfoxide reductase'', ''methionine sulfoxide reductase'', ''L-methionine:oxidized-thioredoxin S-oxidoreductase'') is an enzyme with systematic name ''L-methionine:thioredoxin-disulfide S-oxidoreductase''. This enzyme catalyses the following chemical reaction : L-methionine + thioredoxin disulfide + H2O \rightleftharpoons L-methionine S-oxide + thioredoxin In the reverse reaction, dithiothreitol can replace reduced thioredoxin. S-Methionine-S-oxide and R-Methionine-S-oxide require different Methionine-S-oxide reductases, named Methionine-S-oxide reductase A and Methionine-S-oxide reductase B respectively. A Methionine-S-oxide reductase B named AtMSRB plays a large role in salt tolerance in Arabidopsis Thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onion
An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classified as a separate species until 2011. The onion's close relatives include garlic, scallion, leek, and chives. The genus contains several other species variously called onions and cultivated for food, such as the Japanese bunching onion '' Allium fistulosum'', the tree onion ''Allium'' × ''proliferum'', and the Canada onion '' Allium canadense''. The name '' wild onion'' is applied to a number of ''Allium'' species, but ''A. cepa'' is exclusively known from cultivation. Its ancestral wild original form is not known, although escapes from cultivation have become established in some regions. The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syn-Propanethial-S-oxide
''syn''-Propanethial ''S''-oxide (or (''Z'')-propanethial ''S''-oxide), a member of a class of organosulfur compounds known as thiocarbonyl S-oxide, ''S''-oxides (formerly "sulfines"), is a volatile liquid that acts as a lachrymatory agent (triggers tearing and stinging on contact with the eyes). Onion release The chemical is released from onions, ''Allium cepa'', as they are sliced. The release is due to the breaking open of the onion cells, which releases enzymes called alliinases. Alliinases then break down amino acid sulfoxides, generating sulfenic acids. A specific sulfenic acid, allicin or 1-propenesulfenic acid, is rapidly rearranged by another enzyme, the lachrymatory factor synthase (LFS) to give ''syn''-propanethial ''S''-oxide. Vapors from this volatile liquid induces tearing. Related compounds A structurally related lachrymatory compound, ''syn''-butanethial ''S''-oxide, C4H8OS, has been found in another genus ''Allium'' plant, ''Allium siculum''. Propanethial S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Dithiolane
1,2-Dithiolane is an organosulfur compound with the formula . It is also classified as a heterocycle derived from cyclopentane by replacing two methylene bridges ( units) with a disulfide group. 1,3-Dithiolane is an isomer. The parent molecule is unimportant but substituted derivatives, especially lipoic acid and its derivatives, are often essential for life. Several occur naturally. The parent 1,2-dithiolane is the disulfide derived from 1,3-propanedithiol. It is however unstable with respect to oligomerization. In general, 1,3-dithiols are superior reductants relative to monothiols. Natural occurrence Many substituted 1,2-dithiolates are found in nature. The most common is lipoic acid, a chiral dithiolane, which features a pentanoic acid substituent. It is essential for aerobic metabolism in mammals. Some 1,2-dithiolane are found in some foods, such as asparagusic acid in asparagus. The 4-dimethylamino derivative nereistoxin was the inspiration for insecticides that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosulfur Chemistry
Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature is abound with organosulfur compounds—sulfur is vital for life. Of the 20 common amino acids, two (cysteine and methionine) are organosulfur compounds, and the antibiotics penicillin and sulfa drugs both contain sulfur. While sulfur-containing antibiotics save many lives, sulfur mustard is a deadly chemical warfare agent. Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries. Sulfur shares the chalcogen group with oxygen, selenium, and tellurium, and it is expected that organosulfur compounds have similarities with carbon–oxygen, carbon–selenium, and carbon–tell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioketones
In organic chemistry, thioketones (; also known as thiones or thiocarbonyls) are organosulfur compounds related to conventional ketones in which the oxygen has been replaced by a sulfur. Instead of a structure of , thioketones have the structure , which is reflected by the prefix "thio-" in the name of the functional group. Thus the simplest thioketone is thioacetone, the sulfur analog of acetone. Unhindered alkylthioketones typically tend to form polymers or rings. Structure and bonding The C=S bond length of thiobenzophenone is 1.63 Å, which is comparable to 1.64 Å, the C=S bond length of thioformaldehyde, measured in the gas phase. Due to steric interactions, the phenyl groups are not coplanar and the dihedral angle SC-CC is 36°. Unhindered dialkylthiones polymerize or oligomerize but thiocamphor is well characterized red solid. Consistent with the double bond rule, most alkyl thioketones are unstable with respect to dimerization.Organosulfur Chemistry I: Topics in Curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioaldehyde
In organic chemistry, a thial or thioaldehyde is a functional group which is similar to an aldehyde, , in which a sulfur (S) atom replaces the oxygen (O) atom of the aldehyde (R represents an alkyl or aryl group). Thioaldehydes are even more reactive than thioketones. Unhindered thioaldehydes are generally too reactive to be isolated — for example, thioformaldehyde, , condenses to the cyclic trimer 1,3,5-trithiane. Thioacrolein, , formed by decomposition of allicin from garlic, undergoes a self Diels-Alder reaction giving isomeric vinyldithiins. While thioformaldehyde is highly reactive, it is found in interstellar space along with its mono- and di-deuterated isotopologues. With sufficient steric bulk, however, stable thioaldehydes can be isolated. In early work, the existence of thioaldehydes was inferred by trapping processes. For instance the reaction of with benzaldehyde was proposed to form thiobenzaldehyde, which forms a cycloadduct with the dithiophosphine ylides to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfoxide
In organic chemistry, a sulfoxide, also called a sulphoxide, is an organosulfur compound containing a sulfinyl () functional group attached to two carbon atoms. It is a polar functional group. Sulfoxides are oxidized derivatives of sulfides. Examples of important sulfoxides are alliin, a precursor to the compound that gives freshly crushed garlic its aroma, and dimethyl sulfoxide (DMSO), a common solvent. Structure and bonding Sulfoxides feature relatively short S–O distances. In DMSO, the S–O distance is 1.531 Å. The sulfur center is pyramidal; the sum of the angles at sulfur is about 306°.. Sulfoxides are generally represented with the structural formula R−S(=O)−R', where R and R' are organic groups. The bond between the sulfur and oxygen atoms is intermediate of a dative bond and a polarized double bond. The double-bond resonance form implies 10 electrons around sulfur (10-S-3 in N-X-L notation). The double-bond character of the S−O bond may be accou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Oxide
Sulfur oxide Sulfur oxides (SOx) are a group of chemical compounds formed by the combination of sulfur and oxygen. The most common SOx are sulfur dioxide (SO2) and sulfur trioxide (SO3). SOx are produced naturally through volcanic activity and are also released into the atmosphere from human activities like burning fossil fuels and industrial processes. Sulfur oxide (SO''x'') refers to one or more of the following: * Lower sulfur oxides (S''n''O, S7O2 and S6O2) * Sulfur monoxide (SO) and its dimer, Disulfur dioxide (S2O2) * Sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ... (SO2) * Sulfur trioxide (SO3) * Higher sulfur oxides (SO3 and SO4 and polymeric condensates of them) * Disulfur monoxide (S2O) {{Authority control * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep Mantle (geology), mantle remain active areas of investigation. All allotropes (structurally different pure forms of an element) and some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, graphene, etc.), carbon monoxide , carbon dioxide , carbides, and salt (chemistry), salts of inorganic anions such as carbonates, cyanides, cyanates, thiocyanates, isothiocyanates, etc. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it cannot occur within life, living things. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of metals refining and the burning of Sour gas, sulfur-Sour crude oil, bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemy, alchemists as "volatile spirit of sulfur". Structure and bonding SO2 is a bent molecule with ''C''2v Point groups in three dimensions, symmetry point group. A valence bond theory approach considering just ''s'' and ''p'' orbitals would describe the bonding in terms of resonance (chemistry), resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
