{{Chembox | ImageFile = Sinapaldehyde.svg | ImageFile_Ref = {{chemboximage|correct|??}} | ImageSize = 244 | ImageName = Kekulé skeletal formula of sinapaldehyde (2E)-2-en with some implicit hydrogens shown and one explicit hydrogen added | SystematicName = (''E'')-3-(4-Hydroxy-3,5-dimethoxyphenyl)prop-2-enal<ref>{{Cite web|title = AC1L3OEQ - Compound Summary|url = https://pubchem.ncbi.nlm.nih.gov/compound/119216|work = The PubChem Project|location = USA|publisher = National Center for Biotechnology Information}}</ref> | OtherNames = {{ubl| * (''trans'')-3,5-Dimethoxy-4-hydroxycinnamaldehyde * Sinapic aldehyde * Sinapinaldehyde * Sinapoyl aldehyde * Sinapyl aldehyde }} |Section1={{Chembox Identifiers | CASNo = 4206-58-0 | CASNo_Comment = | 3DMet = B00807 | Beilstein = 2215799 | ChemSpiderID = 4444359 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | EINECS = 627-731-3 | KEGG = C05610 | MeSHName = Sinapaldehyde | ChEBI = 27949 | ChEMBL = 225067 | ChEMBL_Ref = {{ebicite|correct|EBI}} | PubChem = 5280802 | SMILES = COC1=CC(=CC(=C1O)OC)/C=C/C=O | StdInChI = 1S/C11H12O4/c1-14-9-6-8(4-3-5-12)7-10(15-2)11(9)13/h3-7,13H,1-2H3/b4-3+ | StdInChIKey = CDICDSOGTRCHMG-ONEGZZNKSA-N }} |Section2={{Chembox Properties | C = 11 | H = 12 | O = 4 | MeltingPtC = 104 to 106 | LogP = 1.686 | pKa = 9.667 | pKb = 4.330 }} |Section3={{Chembox Hazards | GHS_ref=<ref>{{cite web |title=C&L Inventory |url=https://www.echa.europa.eu/web/guest/information-on-chemicals/cl-inventory-database/-/discli/details/160751 |website=www.echa.europa.eu}}</ref> | GHSPictograms = {{GHS07}} | GHSSignalWord = Warning | HPhrases = {{H-phrases|315|319|335}} | PPhrases = {{P-phrases|}} }} |Section4={{Chembox Related | OtherFunction_label = alkenals | OtherFunction = Cinnamaldehyde<br /> Coniferyl aldehyde<br /> DMACA reagent<br /> 2-Nitrocinnamaldehyde }} }}
'''Sinapaldehyde''' is an organic compound with the formula HO(CH<sub>3</sub>O)<sub>2</sub>C<sub>6</sub>H<sub>2</sub>CH=CHCHO. It is a derivative of cinnamaldehyde, featuring one hydroxy group and two methoxy groups as substituents. It is an intermediate in the formation of sinapyl alcohol, a lignol that is a major precursor to lignin.<ref>Wout Boerjan, John Ralph, Marie Baucher "Lignin Biosynthesis" Annu. Rev. Plant Biol. 2003, vol. 54, pp. 519–46. {{doi|10.1146/annurev.arplant.54.031902.134938}}</ref><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 |bibcode=2001PlanC..13.1567L }}</ref>
==Biosynthetic role== In sweetgum (''Liquidambar styraciflua''), sinapaldehyde arises in two steps from coniferyl aldehyde beginning with hydroxylation mediated by coniferyl aldehyde 5-hydroxylase. The diphenol is then methylated at the 5-OH by the action of caffeate ''O''-methyltransferase.<ref>{{cite journal |doi=10.1073/pnas.96.16.8955|title=Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms |year=1999 |last1=Osakabe |first1=Keishi |last2=Tsao |first2=Cheng Chung |last3=Li |first3=Laigeng |last4=Popko |first4=Jacqueline L. |last5=Umezawa |first5=Toshiaki |last6=Carraway |first6=Daniel T. |last7=Smeltzer |first7=Richard H. |last8=Joshi |first8=Chandrashekhar P. |last9=Chiang |first9=Vincent L. |journal=Proceedings of the National Academy of Sciences |volume=96 |issue=16 |pages=8955–8960 |pmid=10430877 |pmc=17714 |bibcode=1999PNAS...96.8955O |doi-access=free }}</ref>
Sinapaldehyde is reduced to the alcohol by the action of dehydrogenase enzymes.<ref name=TPC/> In ''Arabidopsis thaliana'', the enzyme dihydroflavonol 4-reductase uses NADP<sup>+</sup> to reduce sinapaldehyde to sinapyl alcohol.<ref>{{Cite web |url=http://arabidopsisreactome.org/cgi-bin/eventbrowser?DB=test_reactome_9_ath_all&FOCUS_SPECIES=Arabidopsis_thaliana&ID=43094& |title=Dihydroflavonol 4-reductase on arabidopsisreactome.org |access-date=2009-10-26 |archive-date=2016-01-30 |archive-url=https://web.archive.org/web/20160130221202/http://arabidopsisreactome.org/cgi-bin/eventbrowser?DB=test_reactome_9_ath_all&FOCUS_SPECIES=Arabidopsis_thaliana&ID=43094& |url-status=dead }}</ref>
It is found in ''Senra incana'' (Hibisceae). It is a low molecular weight phenol that is susceptible to extraction from cork stoppers into wine.<ref>Polyphenolic Composition of ''Quercus suber'' Cork from Different Spanish Provenances. Elvira Conde, Estrella Cadahía, María Concepción García-Vallejo and Brígida Fernández de Simón, J. Agric. Food Chem., 1998, volume 46, pp 3166–3171 {{doi|10.1021/jf970863k}}</ref>
== See also == {{Div col|colwidth=16em}} *Phenolic content in wine *Syringaldehyde *Syringol *Syringic acid *Acetosyringone *Sinapinic acid *Sinapine *Canolol {{Div col end}}
== References == {{Reflist}}
Category:Natural phenols Category:Aldehydes Category:O-methylated phenylpropanoids