Syringol

{{chembox | Verifiedimages = changed | Watchedfields = changed | verifiedrevid = 470475699 | Chembox_ref =<ref name=Aldrich>[https://www.sigmaaldrich.com/US/en/product/aldrich/d135550 2,6-Dimethoxyphenol] at Sigma-Aldrich</ref> | Name = Syringol | ImageFile_Ref = {{chemboximage|correct|??}} | ImageFile = Syringol.png | ImageSize = 150px | ImageName = Syringol | PIN = 2,6-Dimethoxyphenol | OtherNames = Syringol 2-Hydroxy-1,3-dimethoxybenzene Pyrogallol 1,3-dimethyl ether |Section1={{Chembox Identifiers | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 955 | SMILES = O(c1cccc(OC)c1O)C | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 6774 | PubChem = 7041 | EC_number = 202-041-1 | Beilstein = 1526871 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 4UQT464H8K | InChI = 1/C8H10O3/c1-10-6-4-3-5-7(11-2)8(6)9/h3-5,9H,1-2H3 | InChIKey = KLIDCXVFHGNTTM-UHFFFAOYAG | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 109652 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C8H10O3/c1-10-6-4-3-5-7(11-2)8(6)9/h3-5,9H,1-2H3 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = KLIDCXVFHGNTTM-UHFFFAOYSA-N | CASNo = 91-10-1 | CASNo_Ref = {{cascite|correct|CAS}} }} |Section2={{Chembox Properties | Formula = C8H10O3 | MolarMass = 154.16 g/mol | Appearance = colorless solid | Density = 1.15857 g/cm3 (60 °C) <ref name="Baird2019">{{cite journal |last1=Baird |first1=Zachariah Steven |last2=Uusi-Kyyny |first2=Petri |last3=Pokki |first3=Juha-Pekka |last4=Pedegert |first4=Emilie |last5=Alopaeus |first5=Ville |title=Vapor Pressures, Densities, and PC-SAFT Parameters for 11 Bio-compounds |journal=International Journal of Thermophysics |date=6 Nov 2019 |volume=40 |issue=11 |page=102 |doi=10.1007/s10765-019-2570-9|bibcode=2019IJT....40..102B |doi-access=free }}</ref> | MeltingPtC = 50 to 57 | MeltingPt_notes = | BoilingPtC = 262 | BoilingPt_ref = <ref name="Baird2019" /> | VaporPressure = 15.8 Pa (60 °C) <ref name="Baird2019" /> | Solubility = Slightly soluble }} |Section3={{Chembox Hazards | Hazards_ref =<ref name=Aldrich/> | FlashPtC = 140 }} }}

'''Syringol''' is the organic compound with the formula HO(CH3O)2C6H3. The molecule is a phenol, with methoxy groups in the flanking (2 and 6) positions. It is the symmetrically dimethylated derivative of pyrogallol. It is a colorless solid, although typical samples are brown owing to air-oxidized impurities. Together with guaiacol, syringol and its derivatives are produced by the pyrolysis of lignin. Specifically, syringol is derived from the thermal decomposition of the sinapyl alcohol component. As such, syringol is a main component of wood smoke.

==Syringyl/guaiacyl ratio== Lignin, comprising a major fraction of biomass, is sometimes classified according to the '''syringyl''' component. Pyrolysis of lignin derived from sinapyl alcohol affords syringol. The conversion involves replacement of the propenyl alcohol substituent of the sinapyl alcohol by hydrogen. A high syringyl (or S) content is indicative of lignin from angiosperms. In contrast, pyrolysis of lignin from gymnosperms gives more guaiacol, resulting from conversion of coniferyl alcohol. These lignins have a high guaiacyl (or G) content.<ref name=TPC>{{cite journal |doi=10.1105/tpc.010111|title=The Last Step of Syringyl Monolignol Biosynthesis in Angiosperms is Regulated by a Novel Gene Encoding Sinapyl Alcohol Dehydrogenase |year=2001 |last1=Li |first1=Laigeng |last2=Cheng |first2=Xiao Fei |last3=Leshkevich |first3=Jacqueline |last4=Umezawa |first4=Toshiaki |last5=Harding |first5=Scott A. |last6=Chiang |first6=Vincent L. |journal=The Plant Cell |volume=13 |issue=7 |pages=1567–1586 |pmid=11449052 |pmc=139549 }}</ref>

==Food preparation== In preparation of food by smoking, syringol is the main chemical responsible for the smoky aroma, while guaiacol contributes mainly to taste. Artificial liquid or solid smoke flavorings also contain these chemicals, on average composing 13.73% and 13.42% of those products by mass respectively.<ref>{{cite book |editor=Chichester, C. O. |editor2=Mrak, E. M. |editor3=Schweigert, B. S. |title=Advances in Food Research|volume =29|year=1984|publisher=Academic Press |location=London|isbn=978-0-08-056748-8|pages=129–130|url=https://books.google.com/books?id=PO4DhgFWIuQC}}</ref>

==Chemical feedstock== Pyrolysis oil, a biofuel derived from woody biomass, can be optimized to yield syringol as a byproduct, potentially competing with petroleum-derived phenols.<ref>{{cite journal|author1=Dinesh Mohan |author2=Charles U. Pittman Jr. |author3=Philip H. Steele |title=Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review|journal=Energy & Fuels|year=2006|volume=20|issue=3|page=863|doi=10.1021/ef0502397}}</ref> Some studies indicate that syringol can substitute for phenol formaldehyde resin, a commonly used, water resistant adhesive for plywood.<ref>{{cite journal|last=Bridgwater|first=A.V. |author2=Effendi A |author3=Gerhauser H|title=Production of Renewable Phenolic Resin by Thermochemical Conversion of Biomass: A Review|journal=Renewable and Sustainable Energy Reviews|year=2008|volume=12|issue=8|pages=2092–2116 |doi=10.1016/j.rser.2007.04.008}}</ref>

== See also == {{Div col|colwidth=16em}} *Phenolic content in wine *Syringaldehyde *Syringic acid *Acetosyringone *Sinapaldehyde *Sinapinic acid *Sinapine *Canolol {{Div col end}}

== References == {{reflist}}

Category:O-methylated natural phenols