{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 423643879 | Name = Purpurogallin | ImageFile = Purpurogallin.svg | ImageSize = 200px | ImageName = Chemical structure of purpurogallin | ImageAlt = Chemical structure of purpurogallin | PIN = 1,7,8,9-Tetrahydroxy-2''H''-benzo[7]annulen-2-one | OtherNames = Purpurogalline<br>2,3,4,6-Tetrahydroxybenzocyclohepten-5-one<br>PPG |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|??}} | CASNo = 569-77-7 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = L3Z7U4N28P | CASNoOther = | PubChem = 5281571 | SMILES = C1=CC(=O)C(=C2C(=C1)C=C(C(=C2O)O)O)O | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C11H8O5/c12-6-3-1-2-5-4-7(13)10(15)11(16)8(5)9(6)14/h1-4,13,15-16H,(H,12,14) | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = WDGFFVCWBZVLCE-UHFFFAOYSA-N | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 4444893 | InChI = | MeSHName = C026133 | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 8647 | KEGG_Ref = {{keggcite|changed|kegg}} | KEGG = C09964 }} |Section2={{Chembox Properties | C=11|H=8|O=5 | Appearance = Red crystalline solid | Density = | MeltingPt = | BoilingPt = | Solubility = }} }}
'''Purpurogallin''' is an aglycone natural product. It is an orange-red solid that is soluble in polar organic solvents but not in water. Its glycoside (ether-linked to sugar), called dryophantin, is found in nutgalls and oak barks. Purpurogallin can be prepared by oxidation of pyrogallol with sodium periodate.<ref>{{cite journal |doi=10.1021/acs.jchemed.1c00699|title=Synthesis and Analytical Characterization of Purpurogallin: A Pharmacologically Active Constituent of Oak Galls |year=2022 |last1=Kelly-Hunt |first1=Alexandra E. |last2=Mehan |first2=Aman |last3=Brooks |first3=Sarah |last4=Leanca |first4=Miron A. |last5=McKay |first5=Jack E. D. |last6=Mahamed |first6=Nashad |last7=Lambert |first7=Daniel |last8=Dempster |first8=Nicola M. |last9=Allen |first9=Robert J. |last10=Evans |first10=Andrew R. |last11=Sarker |first11=Satyajit D. |last12=Nahar |first12=Lutfun |last13=Sharples |first13=George P. |last14=Drew |first14=Michael G. B. |last15=Fielding |first15=Alistair J. |last16=Ismail |first16=Fyaz M. D. |journal=Journal of Chemical Education |volume=99 |issue=2 |pages=983–993 |bibcode=2022JChEd..99..983K |s2cid=245366264 |url=https://researchonline.ljmu.ac.uk/id/eprint/16051/3/Synthesis%20and%20analytical%20characterization%20of%20purpurogallin%20-%20a%20pharmacologically%20active%20constituent%20of%20oak%20galls.pdf }}</ref>
==Medicinal aspects== Purpurogallin is bioactive<ref>{{cite journal | doi = 10.1016/0006-2952(96)00447-9| pmid = 8831727| title = Molecular structure and antioxidant specificity of purpurogallin in three types of human cardiovascular cells| journal = Biochemical Pharmacology| volume = 52| issue = 7| pages = 1073–80| year = 1996| last1 = Wu| first1 = Tai-Wing| last2 = Zeng| first2 = Ling-Hua| last3 = Wu| first3 = Jun| last4 = Fung| first4 = Kwok-Pui| last5 = Weisel| first5 = Richard D| last6 = Hempel| first6 = Andrew| last7 = Camerman| first7 = Norman}}</ref> It can inhibit 2-hydroxy and 4-hydroxyestradiol methylation by catechol-O-methyltransferase.<ref>{{cite journal | doi = 10.1016/j.bmc.2005.01.037| title = Benzotropolone inhibitors of estradiol methylation: Kinetics and in silico modeling studies| journal = Bioorganic & Medicinal Chemistry| volume = 13| issue = 7| pages = 2501–7| year = 2005| last1 = Lambert| first1 = Joshua D| last2 = Chen| first2 = Dapeng| last3 = Wang| first3 = Ching Y| last4 = Ai| first4 = Ni| last5 = Sang| first5 = Shengmin| last6 = Ho| first6 = Chi-Tang| last7 = Welsh| first7 = William J| last8 = Yang| first8 = Chung S| pmid = 15755652}}</ref> It potently and specifically inhibits TLR1/TLR2 activation pathway.<ref>{{cite journal | doi = 10.1002/anie.201204910| pmid = 22969053| title = Discovery of Small-Molecule Inhibitors of the TLR1/TLR2 Complex| journal = Angewandte Chemie International Edition| volume = 51| issue = 49| pages = 12246–9| year = 2012| last1 = Cheng| first1 = Kui| last2 = Wang| first2 = Xiaohui| last3 = Zhang| first3 = Shuting| last4 = Yin| first4 = Hang| pmc=3510333}}</ref>
==Historical work== Purpurogallin, obtained by oxidation of pyrogallol, attracted attention for dyeing. Arthur George Perkin (son of William Henry Perkin, discoverer of the dye mauvine) reported early characterization including the formation of trimethyl ether and the triacetate..<ref>{{cite journal |doi=10.1039/ct9038300192 |title=XX.—Purpurogallin. I |date=1903 |last1=Perkin |first1=Arthur George |last2=Steven |first2=Alec Bowring |journal=J. Chem. Soc., Trans. |volume=83 |pages=192–201 |url=https://zenodo.org/record/1614846 }}</ref>
==References== {{reflist}}
Category:Polyphenols Category:Tropolones Category:Tetrols Category:Azulenes Category:Pyrogallols
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