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Tetronic Acid
Tetronic acid is a chemical compound, classified as a γ-lactone, with the molecular formula C4H4O3. It interconverts between keto and enol tautomers: : Many natural products such as ascorbic acid (vitamin C), penicillic acid, pulvinic acids, and abyssomicins possess the β-keto-γ-butyrolactone motif of tetronic acid. In organic synthesis, it is used as a precursor for other substituted and ring-fused furans and butenolides. It is also forms the structural core of a class of pesticides, known as tetronic acid insecticides, which includes spirodiclofen Spirodiclofen is an acaricide and insecticide used in agriculture to control mites and San Jose scale. In the United States, it is used on citrus, grapes, pome fruit, stone fruit, and tree nut crops. Spirodiclofen belongs to the tetronic acid cl ... and spiromesifen. See also * 5-Hydroxy-2(5H)-furanone References {{reflist Furanones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma-Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore Corporation, Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactone
Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the corresponding hydroxycarboxylic acids, which takes place spontaneously when the ring that is formed is five- or six-membered. Lactones with three- or four-membered rings (α-lactones and β-lactones) are very reactive, making their isolation difficult. Special methods are normally required for the laboratory synthesis of small-ring lactones as well as those that contain rings larger than six-membered. Nomenclature Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tautomer
Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydrogen atom within the compound. The phenomenon of tautomerization is called tautomerism, also called desmotropism. Tautomerism is for example relevant to the behavior of amino acids and nucleic acids, two of the fundamental building blocks of life. Care should be taken not to confuse tautomers with depictions of "contributing structures" in chemical resonance. Tautomers are distinct chemical species that can be distinguished by their differing atomic connectivities, molecular geometries, and physicochemical and spectroscopic properties, whereas resonance forms are merely alternative Lewis structure (valence bond theory) depictions of a single chemical species, whose true structure is best described as the "average" of the idealized, hypo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Product
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synthesis (both semisynthesis and total synthesis) and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets. The term natural product has also been extended for commercial purposes to refer to cosmetics, dietary supplements, and foods produced from natural sources without added artificial ingredients. Within the field of organic chemistry, the definition of natural products is usually restricted to organic compounds isolated from natural sources that are produced by the pathways of primary or secondary metabolism. Within the field of medicinal chemistry, the definition is often further restricted to secondary metabolites. Secondary metabolites (or specialized metabo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascorbic Acid
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) and wrinkles on the face. It is used to prevent and treat scurvy. Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Most animals are able to synthesize their own vitamin C. However, apes (including humans) and monkeys (but not all primates), most bats, some rodents, and certain other animals must acquire it from dietary sources. There is some evidence that regular use of supplements may reduce the duration of the common cold, but it does not appear to prevent infection. It is unclear whether s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penicillic Acid
Penicillic acid is a mycotoxin that is produced by ''Aspergillus flavus'' and ''Penicillium roqueforti'' mold. It is also the major product of acid degradation of penicillin. Its first practical synthesis was reported in 1947 by Ralph Raphael, who had worked on penicillin during World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power .... References Mycotoxins Furanones {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulvinic Acid
Pulvinic acids are natural chemical pigments found in some lichens, derived biosynthetically from the aromatic amino acids phenylalanine and tyrosine, via dimerization and oxidative ring-cleavage of arylpyruvic acids, a process that also produces the related pulvinones. Hydroxypulvinic acid pigments (pulvinic acid type family of pigments) have been found in ''Boletus'' (e.g. '' Boletus erythropus''), '' Boletinus'', '' Chalciporus'', '' Gyrodon'', '' Leccinum'', '' Pulveroboletus'', '' Suillus'' (e.g. ''Suillus luteus'', '' Suillus bovinus'', and '' Suillus grevillei''), ''Paxillus'' (e.g. '' Paxillus involutus''), '' Serpula'' (e.g. '' Serpula lacrymans''), ''Xerocomus'' (e.g. '' Xerocomus chrysenteron''), '' Hygrophoropsis'' (e.g. '' Hygrophoropsis aurantiaca''), '' Retiboletus'' (e.g. '' Retiboletus nigerrimus''), '' Pulveroboletus'' (e.g. '' Pulveroboletus auriflammeus''), and are generally characteristic of Boletales. In addition to pulvinone, derivatives and related pigm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abyssomicin
''Atrop''-abyssomicin C is a polycyclic polyketide-type natural product that is the atropisomer of abyssomicin C. It is a spirotetronate that belongs to the class of tetronate antibiotics, which includes compounds such as tetronomycin, agglomerin, and chlorothricin. In 2006, the Nicolaou group discovered ''atrop''-abyssomicin C while working on the total synthesis of abyssomicin C. Then in 2007, Süssmuth and co-workers isolated ''atrop''-abyssomicin C from '' Verrucosispora maris'' AB-18-032, a marine actinomycete found in sediment of the Japanese sea. They found that ''atrop''-abyssomicin C was the major metabolite produced by this strain, while abyssomicin C was a minor product. The molecule displays antibacterial activity by inhibiting the enzyme PabB ( 4-amino-4-deoxychorismate synthase), thereby depleting the biosynthesis of '' p'' -aminobenzoate. Structure ''Atrop''-abyssomicin C has a complex, yet intriguing structural topography. The compound contains an oxabicycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one of the most important branches of organic chemistry. There are several main areas of research within the general area of organic synthesis: '' total synthesis'', '' semisynthesis'', and ''methodology''. Total synthesis A total synthesis is the complete chemical synthesis of complex organic molecules from simple, commercially available petrochemical or natural precursors. Total synthesis may be accomplished either via a linear or convergent approach. In a ''linear'' synthesis—often adequate for simple structures—several steps are performed one after another until the molecule is complete; the chemical compounds made in each step are called synthetic intermediates. Most often, each step in a synthesis refers to a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furan
Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature. It is soluble in common organic solvents, including alcohol, ether, and acetone, and is slightly soluble in water. Its odor is "strong, ethereal; chloroform-like". It is toxic and may be carcinogenic in humans. Furan is used as a starting point for other speciality chemicals. History The name "furan" comes from the Latin ''furfur'', which means bran. (Furfural is produced from bran.) The first furan derivative to be described was 2-furoic acid, by Carl Wilhelm Scheele in 1780. Another important derivative, furfural, was reported by Johann Wolfgang Döbereiner in 1831 and characterised nine years later by John Stenhouse. Furan itself was first prepared by Heinrich Limp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
