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 ja 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 Watchedfields changed verifiedrevid 443355037 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 Ref cascite correct ?? CASNo 108 97 4 PubChem 7968 ChEBI Ref ebicite correct EBI ChEBI 37966 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 Category 4 Pyrones heterocyclic stub 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 albumin, 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 fr Benzopyrone sv Bensopyron ... more details
chlorides. Citation needed date March 2008 gallery Image 4 Pyranone.png 4 Pyrone gallery The most common natural products containing a 2 pyrone are the bufanolides and kavalactone s. References references DEFAULTSORT Pyrone, 2 Category 2 Pyrones de 2 Pyron es 2 Pirona fr Pyran 2 one fi 2 pyroni ... more details
chembox Verifiedfields changed 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 DrugBank Ref drugbankcite changed drugbank DrugBank DB01759 ChEBI Ref ebicite changed EBI ChEBI 43572 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 Slight 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 cosmetic ... more details
Chembox Verifiedfields changed Watchedfields changed verifiedrevid 450974443 Reference ref name Merck Merck Index , 11th Edition, 2855 ref ImageFile Dehydroacetic acid.svg ImageFile Ref chemboximage correct ?? ImageName Kekul , skeletal formula of dehydroacetic acid PIN 3 Acetyl 2 hydroxy 6 methyl 4 H pyran 4 one Citation needed date October 2011 OtherNames Biocide 470F Citation needed date October 2011 br Methylacetopyronone Citation needed date October 2011 Section1 Chembox Identifiers Abbreviations DHAA CASNo 520 45 6 CASNo Ref cascite correct CAS PubChem 10623 PubChem Ref Pubchemcite correct Pubchem ChemSpiderID 10177 ChemSpiderID Ref chemspidercite changed chemspider UNII 2KAG279R6R UNII Ref fdacite correct FDA EINECS 208 293 9 MeSHName dehydroacetic acid SMILES CC O C1 C O OC C CC1 O StdInChI 1S C8H8O4 c1 4 3 6 10 7 5 2 9 8 11 12 4 h3,11H,1 2H3 StdInChI Ref stdinchicite changed chemspider StdInChIKey JEQRBTDTEKWZBW UHFFFAOYSA N StdInChIKey Ref stdinchicite changed chemspider Section2 Chembox Properties C 8 H 8 O 4 ExactMass 168.042258744 g mol sup 1 sup Appearance White crystals Density MeltingPtK 382 BoilingPtK 543 Section3 Chembox Hazards EUIndex 607 163 00 2 EUClass Hazchem Xn RPhrases R22 SPhrases S2 Dehydroacetic acid is a pyrone derivative used mostly 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 br Also used in antienzyme toothpastes. 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 Reflist Category Fungicides Category 4 Pyrones Category Alcohols Alcohol stub Heterocyclic stub Ketone stub es cido dehidroac tico ru zh ... more details
unsaturation 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 ... 3325, DOI 10.1039 b607322k ref Image Pyronecycloaddition.png 400px center Pyrone cycloaddition Chromenylium ... 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
one source date February 2012 no footnotes date February 2012 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 bark mill mill s 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 , lute ... more details
chembox Verifiedfields changed verifiedrevid 399524554 ImageFile chromone.svg 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 Ref cascite correct ?? CASNo 491 38 3 PubChem 10286 ChEMBL Ref ebicite changed EBI ChEMBL 13311 SMILES C1 CC C2C C1 C O C CO2 Section2 Chembox Properties C 9 H 6 O 2 Appearance Density MeltingPt BoilingPt Solubility pKb 2.0 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. It is an isomer of coumarin . Derivatives of chromone are collectively known as chromones . Most, though not all, chromones are also phenylpropanoid s. 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 . ref Eucryphin, a new chromone rhamnoside from the bark of Eucryphia cordifolia. R. Tschesche, S. Delhvi, S. Sepulveda and E. Breitmaier, Phytochemistry, Volume 18, Issue 5, 1979, pages 867 869, doi 10.1016 0031 9422 79 80032 1 ref Roger Altounyan studied chromones and eventually found disodium cromoglicate . 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. Cromoglicate is used as a mast cell stabilizer in allergic rhinitis , asthma and allergic conjunctivitis . Comparatively free of side effects, unfortunately its short half life limited its value. Nedocromil sodium was found to have a somewhat longer half life. References references See also F ... more details
6 methoxycoumarin. Flavone or benzo 7 pyrone derivatives are numerous in many cases they or the non ... and quercetin, a dioxy 3 phenyl trioxybenzoy pyrone. Rhamnetin , a splitting product of the glucosides ... chrysin is phenyl dioxybenzo y pyrone. Saponarin, a glucoside found in Saponaria officinalis ... more details
Pyrone Polyketides. Synlett 2006 , 2295 2316. Milne, B. F. Long, P. F. Starcevic, A. Hranueli, D. Jaspars ... Unsaturated Pyrone Polyketides. Synlett 2006 , 2295 2316. Milne, B. F. Long, P. F. Starcevic, A. Hranueli ... more details
chembox verifiedrevid 477499682 Name Maltol ImageFile Maltol.png ImageSize 120px ImageName IUPACName 3 hydroxy 2 methyl 4H pyran 4 one Section1 Chembox Identifiers CASNo Ref cascite correct CAS CASNo 118 71 8 UNII Ref fdacite correct FDA UNII 3A9RD92BS4 SMILES O C1C COC C C1O ChEMBL Ref ebicite correct EBI ChEMBL 31422 PubChem 8369 ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 8066 InChI 1 C6H6O3 c1 4 6 8 5 7 2 3 9 4 h2 3,8H,1H3 InChIKey XPCTZQVDEJYUGT UHFFFAOYAH StdInChI Ref stdinchicite correct chemspider StdInChI 1S C6H6O3 c1 4 6 8 5 7 2 3 9 4 h2 3,8H,1H3 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey XPCTZQVDEJYUGT UHFFFAOYSA N 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 greatl ... more details
Myxopyronin Myx is an alpha pyrone antibiotic , the first in a new class of inhibitors of bacterial RNA polymerase RNAP that target switch 1 and switch 2 of the RNAP switch region. Rifamycin antibacterial agents, which are first line treatments for tuberculosis , and lipiarmycin fidaxomicin, Dificid also target RNAP, but target different sites in RNAP. Myxopyronin does not have cross resistance with rifamycins and lipiarmycin. Myxopyronin may be useful to address the growing problem of drug resistance in tuberculosis. It also may be useful in treatment of methicillin resistant Staphylococcus aureus MRSA . It is in pre clinical development and has not yet started clinical trial s. Myxopyronin was first isolated in 1983 from a soil bacterium by Rolf Jansen and Herbert Irschik. A total synthesis of myxopyronin was first reported in 1998 by James S. Panek and co workers. The target, the mechanism of action, and the structure of the complex of RNAP with myxopyronin were first reported in 2008 by Richard H. Ebright and co workers. Novel analogs of myxopyronin have been synthesized at Anadys Pharmaceuticals San Diego, CA and at Rutgers University Piscataway, NJ . Terence I. Moy and co workers at Cubist Pharmaceuticals Lexington, MA have stated that, based on high resistance rate and high serum protein binding comparable to rifamycins and lipiarmycin , the unmodified natural product myxopyronin B is not a viable starting point for antibiotic development. References Citation last Irschik first Herbert title newspaper Journal of Antibiotics year 1983 url http www.journalarchive.jst.go.jp jnlpdf.php?cdjournal antibiotics1968&cdvol 36&noissue 12&startpage 1651&lang en&from jnlabstract Citation last Panek first James title Total Synthesis and Preliminary Antibacterial Evaluation of the RNA Polymerase Inhibitors Myxopyronin A and B year 1998 last2 Schaus first2 Jennifer V. last3 Lam first3 Kelvin last4 Palfreyman first4 Michael G. last5 Wuonola first5 Mark last6 Gustafson first6 Gary ... more details
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