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Pyrones
Pyrones or pyranones are a class of heterocyclic chemical compounds. They contain an unsaturated six-membered ring containing one oxygen atom and a ketone functional group. There are two isomers denoted as 2-pyrone and 4-pyrone. The 2-pyrone (or α-pyrone) structure is found in nature as part of the coumarin ring system. 4-Pyrone (or γ-pyrone) is found in some natural chemical compounds such as chromone, maltol and kojic acid. See also * Furanone 2-Furanone is a heterocyclic organic compound. It is also known as γ-crotonolactone (GCL), as it is formally the lactone derived from γ-hydroxyisocrotonic acid. The chemical is colloquially called "butenolide", and is the parent structure for th ..., which has one fewer carbon atom in the ring. References {{heterocyclic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-Pyranone
4-Pyrone (γ-pyrone or pyran-4-one) is an unsaturated cyclic chemical compound with the molecular formula C5H4O2. It is isomeric with 2-pyrone. Preparation 4-Pyrone is prepared via the thermal decarboxylation of chelidonic acid. Reactions 4-Pyrone and its derivatives react with amines in protic solvents to form 4-Pyridones. Derivatives 4-Pyrone forms the central core of several natural chemical compounds, including maltol, meconic acid, kojic acid, and of the important class of the Flavones. : See also * Pyrone * 4-Pyridone * Dehydroacetic acid Dehydroacetic acid is an organic compound which has several industrial applications. The compound is classified as a pyrone derivative. It presents as an odorless, colorless to white crystalline powder, almost insoluble in water and moderately so ... References {{DEFAULTSORT:Pyrone, 4- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-pyrone
4-Pyrone (γ-pyrone or pyran-4-one) is an unsaturated cyclic chemical compound with the molecular formula C5H4O2. It is isomeric with 2-pyrone. Preparation 4-Pyrone is prepared via the thermal decarboxylation of chelidonic acid. Reactions 4-Pyrone and its derivatives react with amines in protic solvents to form 4-Pyridones. Derivatives 4-Pyrone forms the central core of several natural chemical compounds, including maltol, meconic acid, kojic acid, and of the important class of the Flavones. : See also * Pyrone * 4-Pyridone * Dehydroacetic acid Dehydroacetic acid is an organic compound which has several industrial applications. The compound is classified as a pyrone derivative. It presents as an odorless, colorless to white crystalline powder, almost insoluble in water and moderately so ... References {{DEFAULTSORT:Pyrone, 4- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maltol
Maltol is a naturally occurring organic compound that is used primarily as a flavor enhancer. It is found in the bark of larch tree, in pine needles, and in roasted malt (from which it gets its name). It is a white crystalline powder that is soluble in hot water, chloroform, and other polar solvents. Because it has the odor of cotton candy and caramel, maltol is used to impart a sweet aroma to fragrances. Maltol's sweetness adds to the odor of freshly baked bread, and is used as a flavor enhancer (INS number 636) in breads and cakes. Maltol, like related 3-hydroxy-4-pyrones such as kojic acid, binds to hard metal centers such as Fe3+, Ga3+, Al3+, and VO2+. Related to this property, maltol has been reported to greatly increase aluminum uptake in the body and to increase the oral bioavailability of gallium and iron.{{cite journal , author1=D.M. Reffitt , author2=T.J. Burden , author3=P.T. Seed , author4=J. Wood J , author5=R.P. Thompson , author6=J.J. Powell , title = Assessme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kojic Acid
Kojic acid is a chelation agent produced by several species of fungi, especially ''Aspergillus oryzae'', which has the Japanese common name ''koji''. Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances. It forms a bright red complex with ferric ions. Biosynthesis 13C-Labeling studies have revealed at least two pathways to kojic acid. In the usual route, dehydratase enzymes convert glucose to kojic acid. Pentoses are also viable precursors in which case dihydroxyacetone is invoked as an intermediate. Applications Kojic acid may be used on cut fruits to prevent oxidative browning, in seafood to preserve pink and red colors, and in cosmetics to lighten skin. As an example of the latter, it is used to treat skin diseases like melasma. Kojic acid ... [...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 quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturated And Unsaturated Compounds
In chemistry, a saturated compound is a chemical compound (or ion) that resists the addition reactions, such as hydrogenation, oxidative addition, and binding of a Lewis acids and bases, Lewis base. The term is used in many contexts and for many classes of chemical compounds. Overall, saturated compounds are less reactive than unsaturated compounds. Saturation is derived from the Latin word ''saturare'', meaning 'to fill'. Organic chemistry Unsaturated compounds generally carry out typical addition reactions that are not possible with saturated compounds such as alkanes. A saturated organic compound has only single bonds between carbon atoms. An important class of saturated compounds are the alkanes. Many saturated compounds have functional groups, e.g., alcohols. Unsaturated organic compounds The concept of saturation can be described using various naming systems, formulas, and Analytical chemistry, analytical tests. For instance, IUPAC nomenclature of organic chemistry, IU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids (e.g., testosterone), and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Group
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered heterocycle that shares two carbons with the benzene ring. It can be placed in the benzopyrone chemical class and considered as a lactone. Coumarin is a colorless crystalline solid with a sweet odor resembling the scent of vanilla and a bitter taste. It is found in many plants, where it may serve as a chemical defense against predators. By inhibiting synthesis of vitamin K, a related compound is used as the prescription drug warfarin – an anticoagulant – to inhibit formation of blood clots, deep vein thrombosis, and pulmonary embolism. Etymology Coumarin is derived from ''coumarou'', the French word for the tonka bean. The word ''tonka'' for the tonka bean is taken from the Galibi (Carib) tongue spoken by natives of French G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromone
Chromone (or 1,4-benzopyrone) is a derivative of benzopyran with a substituted keto group on the pyran ring. It is an isomer of coumarin. Derivatives of chromone are collectively known as ''chromones''. Most, though not all, chromones are also phenylpropanoids. Examples * 6,7-dimethoxy-2,3-dihydrochromone has been isolated from ''Sarcolobus globosus''. * Eucryphin, a chromone rhamnoside, can be isolated from the bark of ''Eucryphia cordifolia''. * Cromolyn (disodium cromoglicate) was found to inhibit antigen challenge as well as stress induced symptoms.HOWELL, J.B. & ALTOUNYAN, R.E. (1967). A double-blind trial of disodium cromoglycate in the treatment of allergic bronchial asthma. Lancet, 2, 539–542Abstract/ref> Cromoglicate is used as a mast cell stabilizer in allergic rhinitis, asthma and allergic conjunctivitis. * Nedocromil sodium was found to have a somewhat longer half-life than cromolyn; however, production was discontinued in the US in 2008. * Xanthone with a se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
