Image 2 Pyranone.png thumb right 75px 2 Pyrone Image 4 Pyranone.png thumb right 75px 4 Pyrone Pyrones or pyranones are a class of cyclic chemical compounds. They contain an saturation chemistry 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 pyrone structure is found in nature as part of the coumarin ring system. 4 Pyrone or pyrone is found in some natural chemical compounds such as chromone , maltol and kojic acid . References Introduction to Organic Chemistry , Andrew Streitwieser, Jr. and Clayton H. Heathcock, Third Edition, pp 1038 1040. ISBN 0 02 418140 4 Category Pyrones heterocyclic stub de Pyrone fr Pyrone nl Pyron zh ... more details
DISPLAYTITLE C sub 5 sub H sub 4 sub O sub 2 sub The molecular formula C sub 5 sub H sub 4 sub O sub 2 sub may refer to Furfural Pyrone s 2 Pyrone 4 Pyrone MolFormDisambig fr C5H4O2 ... more details
chembox verifiedrevid 399300108 Reference ref http www.sigmaaldrich.com catalog search ProductDetail ALDRICH 463159 2H Pyran 2 one at Sigma Aldrich ref ImageFile 2 Pyranone.png ImageSize 100px IUPACName Pyran 2 one OtherNames Pyrone br 2 Pyranone br 2 H Pyran 2 one Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 61462 InChI 1 C5H4O2 c6 5 3 1 2 4 7 5 h1 4H InChIKey ZPSJGADGUYYRKE UHFFFAOYAI StdInChI Ref stdinchicite correct chemspider StdInChI 1S C5H4O2 c6 5 3 1 2 4 7 5 h1 4H StdInChIKey Ref stdinchicite correct chemspider StdInChIKey ZPSJGADGUYYRKE UHFFFAOYSA N CASNo 504 31 4 PubChem 68154 SMILES O C 1O C C C C 1 Section2 Chembox Properties Formula C sub 5 sub H sub 4 sub O sub 2 sub MolarMass 96.08 Appearance Density 1.197 g mL MeltingPt BoilingPt 102 103 C at 20 mmHg Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition 2 Pyrone pyrone or pyran 2 one is an saturation chemistry unsaturated cyclic chemical compound with the molecule molecular formula C sub 5 sub H sub 4 sub O sub 2 sub . It is isomer ic with 4 pyrone . 2 Pyrone is used in organic synthesis as a building block for more complex chemical structures because it may participate in a variety of cycloaddition reaction s to form bicyclic lactone s. For example, it readily undergoes Diels Alder reaction s with alkyne s producing, upon loss of carbon dioxide , substituted benzene s. ref Woodard BT, Posner G H. Recent Advances in Diels Alder Cycloadditions Using 2 Pyrones. Advances in Cycloaddition . 1999, 5, 47 83. ref . The Gogte Synthesis 1938 is a method for the alkylation of certain pyrones with acid chlorides Citation needed date March 2008 . gallery Image 4 Pyranone.png 4 Pyrone gallery The most famous natural products are Bufanolides and Kavalactones or Kavapyrones . References references DEFAULTSORT Pyrone, 2 Category 2 Pyrones de 2 Pyron fr Pyran 2 one fi 2 pyroni ... more details
chembox verifiedrevid 399328858 Reference ref http www.sigmaaldrich.com catalog search ProductDetail ALDRICH 177229 4H Pyran 4 one at Sigma Aldrich ref ImageFile 4 Pyranone.png ImageSize 80px IUPACName Pyran 4 one OtherNames Pyrone br 4 Pyranone Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 7680 InChI 1 C5H4O2 c6 5 1 3 7 4 2 5 h1 4H InChIKey CVQUWLDCFXOXEN UHFFFAOYAG SMILES1 O C 1 C C O C C 1 StdInChI Ref stdinchicite correct chemspider StdInChI 1S C5H4O2 c6 5 1 3 7 4 2 5 h1 4H StdInChIKey Ref stdinchicite correct chemspider StdInChIKey CVQUWLDCFXOXEN UHFFFAOYSA N CASNo 108 97 4 PubChem 7968 SMILES C1 COC CC1 O Section2 Chembox Properties Formula C sub 5 sub H sub 4 sub O sub 2 sub MolarMass 96.08 Appearance Density MeltingPt 32 34 C, 305 307 K BoilingPt 210 215 C, 483 488 K Solubility Section3 Chembox Hazards MainHazards FlashPt 101 C Autoignition 4 Pyrone pyrone or pyran 4 one is an saturation chemistry unsaturated cyclic chemical compound with the molecular formula C sub 5 sub H sub 4 sub O sub 2 sub . It is isomer ic with 2 pyrone . 4 Pyrone forms the central core of several natural chemical compounds including maltol and kojic acid and of the important class of the Flavones . class wikitable Image Maltol.png 70px Image KojicAcid.png 120px Maltol Kojic acid See also 4 pyridone References references DEFAULTSORT Pyrone, 4 heterocyclic stub Category 4 Pyrones fr Pyran 4 one fi 4 pyroni ... more details
Benzopyrone may refer to either of two ketone derivatives of benzopyran which constitute the core skeleton of many flavonoid compounds Chromone 1 benzopyran 4 one Coumarin 1 benzopyran 2 one Certain simple benzopyrones have clinical medical value as an edema modifiers. Coumarin and other benzopyrone s, such as 5,6 benzopyrone, 1,2 benzopyrone, diosmin and others are known to stimulate macrophages to degrade extracellular albumen, allowing faster resorption of edematous fluids. ref http content.nejm.org cgi content full 329 16 1158 full content of NEJM article . Treatment of Lymphedema of the Arms and Legs with 5,6 Benzo alpha pyrone. John R. Casley Smith, Robert Gwyn Morgan, and Neil B. Piller Volume 329 1158 1163 October 14, 1993 Number 16. ref ref http www.lymphoedema.org.au bp.html Review of benzypyrone drugs and edema ref Naturally occurring coumarin is also the basis for various 4 hydroxybenzopyrone based molecules which occur naturally dicoumarol and are made synthetically warfarin and function as anticoagulants. References reflist Category Chromenes sv Bensopyron ... more details
chembox verifiedrevid 410570835 ImageFile KojicAcid.svg IUPACName 5 Hydroxy 2 hydroxymethyl 4H pyran 4 one OtherNames Kojic acid, 5 Hydroxy 2 hydroxymethyl 4 pyrone, 2 Hydroxymethyl 5 hydroxy pyrone Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 3708 ChEMBL Ref ebicite correct EBI ChEMBL 287556 StdInChI Ref stdinchicite correct chemspider StdInChI 1S C6H6O4 c7 2 4 1 5 8 6 9 3 10 4 h1,3,7,9H,2H2 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey BEJNERDRQOWKJM UHFFFAOYSA N CASNo Ref cascite correct CAS CASNo 501 30 4 EINECS 207 922 4 PubChem 3840 SMILES O C1 C C O C C1 O CO UNII Ref fdacite correct FDA UNII 6K23F1TT52 KEGG Ref keggcite correct kegg KEGG C14516 InChI 1 C6H6O4 c7 2 4 1 5 8 6 9 3 10 4 h1,3,7,9H,2H2 RTECS UQ0875000 Section2 Chembox Properties Formula C sub 6 sub H sub 6 sub O sub 4 sub MolarMass 142.11 g mol Appearance Tan powder Density MeltingPt 152 155 C BoilingPt Solubility Soluble pKa 9.40 ref Bjerrum, J., et al. Stability Constants , Chemical Society, London, 1958. ref Section3 Chembox Hazards MainHazards FlashPt Autoignition RPhrases R36 37 38 SPhrases S22 , S24 25 Kojic acid C sub 6 sub H sub 6 sub O sub 4 sub 5 hydroxy 2 hydroxymethyl 4 pyrone is a chelation agent produced by several species of fungi, especially Aspergillus oryzae , which has the Japanese common name koji . ref cite journal title The constitution of kojic acid, a gamma pyrone derivative formed by Aspergillus oryzae from carbohydrates author Yabuta T journal Journal of the Chemical Society volume 125 issue pages 575 587 year 1924 doi ref Kojic acid is a by product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. Fact date October 2007 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. ref http www.fao.org ag Ags agsi ENZYMEFINAL Enzymatic 20Browning.html KOJIC K ... more details
chembox ImageFile chromone.png ImageSize 150px IUPACName Chromen 4 one OtherNames 4 Chromone 1,4 Benzopyrone 4 H Chromen 4 one Benzo gamma pyrone 4 H 1 Benzopyran 4 one 1 Benzopyran 4 one 4 H Benzo b pyran 4 one Section1 Chembox Identifiers CASNo 491 38 3 PubChem 10286 SMILES C1 CC C2C C1 C O C CO2 Section2 Chembox Properties C 9 H 6 O 2 Appearance Density MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Chromone or 1,4 benzopyrone is a derivative of benzopyrans benzopyran with a substituted ketone keto group on the pyran ring. Derivatives of chromone are collectively known as chromones . Most, though not all, chromones are also phenylpropanoid s. 6,7 dimethoxy 2,3 dihydrochromone has been isolated from Sarcolobus globosus . Examples Cromoglicate is used as a mast cell stabilizer in allergic rhinitis , asthma and allergic conjunctivitis . Roger Altounyan studied chromones and eventually found disodium cromoglycate . ref HOWELL, J.B. & ALTOUNYAN, R.E. 1967 . A double blind trial of disodium cromoglycate in the treatment of allergic bronchial asthma. Lancet, 2, 539 542. http www.ncbi.nlm.nih.gov entrez query.fcgi?holding npg&cmd Retrieve&db PubMed&list uids 4166895&dopt Abstract Abstract ref This drug was found to inhibit antigen challenge as well as stress induced symptoms. Comparatively free of side effects, unfortunately the short half life limited its value. Nedocromil sodium was found to have a somewhat longer half life. References references See also Furanochromone s Coumarin External links PubChem 10286 4 chromone MeshName Chromones http www.organic chemistry.org synthesis heterocycles chromones flavones.shtm Synthesis at organic chemistry.org Phenylpropanoid Category Chromones fr Chromones it Cromone pl Kromony sv Kromon zh ... more details
chembox verifiedrevid 389070450 Reference ref name Merck Merck Index , 11th Edition, 2855 ref ImageFile Dehydroacetic acid.png ImageSize 150px IUPACName 3 acetyl 2 hydroxy 6 methyl 4 H pyran 4 one OtherNames Methylacetopyronone br Biocide 470F Abbreviations DHAA Section1 Chembox Identifiers ChemSpiderID 109553 UNII Ref fdacite UNII 2KAG279R6R CASNo Ref cascite CASNo 520 45 6 PubChem 10623 SMILES O C C C 1C O C C C OC 1O Section2 Chembox Properties C 8 H 8 O 4 MolarMass 168.14672 Appearance White crystalline powder Density MeltingPt 109 111 C sublimes BoilingPtC 269.9 Solubility 0.1 Section3 Chembox Hazards MainHazards FlashPt Autoignition Dehydroacetic acid is a pyrone derivative used as a fungicide and bactericide . It is used to reduce pickled cucumber pickle bloating as a preservative for squash plant squash and strawberry strawberries . ref Handbook of Biocide and Preservative Use , Harold William Rossmoore, p. 341 ISBN 0751402125 ref The sodium salt chemistry salt , sodium dehydroacetate, is often used in place of dehydroacetic acid because of its greater solubility in water. Industrially, it is also used as a plasticizer in a variety of synthetic resins. ref name Merck References references Category Fungicides Category 4 Pyrones Category Alcohols ketone stub ru zh ... more details
of 5 acetyl 4 methoxy 6 methyl 2 pyrone 3 to macrophomic acid is thought to proceed by either a concerted ... is not yet understood completely. In the conversion of the 2 pyrone 3 , oxaloacetate 1 is decarboxylated ... site of the enzyme. Then, the coordinated enolate can either add to the 2 pyrone 3 through a Michael ... of the pyrone to form intermediate 4 . Next, this intermediate undergoes an aldol condensation to form ... complex with Mg sup 2 sup . Next, the enolate complex adds to the pyrone through a Diels Alder ... more details
Image Quercitrin.png thumb right 200px Chemical structure of quercitrin Quercitron is a yellow natural dye obtained from the bark of the Eastern Black Oak Quercus velutina , a forest tree indigenous in North America . The name is a shortened form of quercicitron, from Latin quercus , oak, and citron , lemon, and was invented by Dr Edward Bancroft 1744 1821 , who by act of parliament in 1785 was granted special privileges in regard to the importation and use of the substance. The dyestuff is prepared by grinding the bark in mills after it has been freed from its black epidermal layer , and sifting the product to separate the fibrous matter , the fine yellow powder which remains forming the quercitron of commerce. The ruddy orange decoction of quercitron contains quercitannic acid , whence its use in tanning , and an active dyeing principle, quercitrin , C sub 21 sub H sub 20 sub O sub 12 sub . The latter substance is a glycoside , and in aqueous solution under the influence of mineral acids it yields quercetin , C sub 15 sub H sub 10 sub O sub 7 sub , which is precipitated, and the methyl pentose rhamnose . Quercetin is a crystalline powder of a brilliant citron yellow color, entirely insoluble in cold water and dissolving only sparingly in hot water, but quite soluble in alcohol. Either by itself or in some form of its glucoside quercitrin, quercetin is found in several vegetable substances, among others in cutch , in Persian berries Rhamnus cathartica , buckwheat leaves Fagopyrum esculentum , Zante fustic wood Rhus cotinus , and in rose petal s. Chemically, quercetin is a member of a fairly extensive class of natural coloring matters derived from phenyl benzoyl pyrone or flavone , the constitution of which followed on the researches of St von Kostanecki, A. G. Perkin, Herzig, Goldschmidt and others. Among the related, coloring matters are chrysin from poplar bud s, apigenin from parsley , luteolin from mignonette and dyer s broom , fisetin from young fustic and yel ... more details
unsaturated lactone or an 2 pyronepyrone or pyran 2 one 2 . Important representatives of this class are the coumarin s. Likewise a 4 hydroxyl pyrylium compound is a pyrone or pyran 4 ..., DOI 10.1039 b607322k ref Image Pyronecycloaddition.png 400px center Pyrone cycloaddition Chromenylium ... more details
chembox verifiedrevid 412344627 Name Maltol ImageFile Maltol.png ImageSize 120px ImageName IUPACName 3 hydroxy 2 methyl 4H pyran 4 one Section1 Chembox Identifiers CASNo Ref cascite CASNo 118 71 8 SMILES O C1C COC C C1O Section2 Chembox Properties Formula C sub 6 sub H sub 6 sub O sub 3 sub MolarMass 126.11 g mol Density 1.348 g cm sup 3 sup MeltingPt 161 162 C BoilingPt 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 E number E636 in breads and cakes. Maltol, like related 3 hydroxy 4 Pyrylium salt pyrone s such as kojic acid , binds to HSAB theory hard metal centers such as Fe sup 3 sup , Ga sup 3 sup , Al sup 3 sup , and VO sup 2 sup . ref cite journal author B. D. Liboiron, K. H. Thompson, G. R. Hanson, E. Lam, N. Aebischer, C. Orvig title New Insights into the Interactions of Serum Proteins with Bis maltolato oxovanadium IV Transport and Biotransformation of Insulin Enhancing Vanadium Pharmaceuticals journal J. Am. Chem. Soc. year 2005 volume 127 pages 5104 5115 doi 10.1021 ja043944n pmid 15810845 issue 14 ref Related to this property, maltol has been reported to greatly increase aluminum uptake in the body ref cite journal author N. Kaneko, H. Yasui, J. Takada, K. Suzuki, H. Sakurai title Orally administrated aluminum maltolate complex enhances oxidative stress in the organs of mice journal J. Inorg. Biochem. year 2004 volume 98 pages 2022 2031 doi 10.1016 j.jinorgbio.2004.09.008 pmid 15541491 issue 12 ref and to increase the oral bioavailability of gallium ref cite journal author L. R. Bernstein, T. Tanner, C. Godf ... more details
Myxopyronin Myx is an alpha pyrone antibiotic , the first in a new class of RNA polymerase RNAP inhibitors which target the switch region of the beta subunit. Rifamycin antibiotics used to treat tuberculosis also target RNAP but at a different site. This new drug should not have cross resistance to treat the growing problem of drug resistance in tuberculosis. It may be also useful in Methicillin resistant Staphylococcus aureus MRSA .It has completed Pre clinical development and has not yet started Clinical trial s. It was first isolated in 1983 from soil by Rolf Jansen and Herbert Irschik. The first total synthesis has been described in 1998 by James S. Panek and co workers. Some analogs of myxopyronin have been synthesized at Anadys Pharmaceuticals San Diego, CA and at USF Tampa, FL . References Citation last Markel Jordan, Labru re Rapha l, Turos edward first title Urea Analog of Myxopyronin B as Potential Inhibitor of Bacterial RNA Polymerase newspaper ABRCMS date 2008 Citation last Lira et al. first title newspaper Bioorganic & Medicinal Chemistry Letters Volume 17, Issue 24, 15 December 2007, Pages 6797 6800 date 2007 Citation last Doundoulakis et al. first title newspaper Bioorganic & Medicinal Chemistry Letters Volume 14, Issue 22, 15 November 2004, Pages 5667 5672 date 2004 Citation last Panek first James title newspaper date 1998 url http www.sciencedaily.com releases 1998 05 980513080643.htm Citation last Panek first James title Total Synthesis and Preliminary Antibacterial Evaluation of the RNA Polymerase Inhibitors Myxopyronin A and B newspaper Journal of Organic Chemistry date 1998 url http www.sciencedaily.com releases 1998 05 980513080643.htm doi 10.1021 jo9721610 last2 Schaus first2 Jennifer V. last3 Lam first3 Kelvin last4 Palfreyman first4 Michael G. last5 Wuonola first5 Mark last6 Gustafson first6 Gary last7 Panek first7 James S. journal The Journal of Organic Chemistry volume 63 issue 7 pages 2401 Citation last Irschik first Herbert title newspaper ... more details
, 7,8 dihydroxy 6 methoxycoumarin. Flavone or benzo 7 pyrone derivatives are numerous in many ... it hydrolyses to rhamnose and quercetin, a dioxy 3 phenyl trioxybenzoy pyrone. Rhamnetin, a splitting ... chrysin is phenyl dioxybenzo y pyrone. Saponarin, a glucoside found in Saponaria officinalis ... more details
, 27 42. Miller, A. K. Trauner, D. Mapping the Chemistry of Highly Unsaturated Pyrone Polyketides .... O. C. 2008 , 27 42. Miller, A. K. Trauner, D. Mapping the Chemistry of Highly Unsaturated Pyrone ... more details
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