Sinapaldehyde

Sinapaldehyde
Names
	Systematic IUPAC name (E)-3-(4-Hydroxy-3,5-dimethoxyphenyl)prop-2-enal
	Other names (trans)-3,5-Dimethoxy-4-hydroxycinnamaldehyde; Sinapic aldehyde; Sinapinaldehyde; Sinapoyl aldehyde; Sinapyl aldehyde; ;
Identifiers
CAS Number	4206-58-0;
3D model (JSmol)	Interactive image;
3DMet	B00807;
Beilstein Reference	2215799
ChEBI	CHEBI:27949;
ChEMBL	ChEMBL225067 ;
ChemSpider	4444359 ;
ECHA InfoCard	100.156.065
EC Number	627-731-3;
KEGG	C05610;
MeSH	Sinapaldehyde
PubChem CID	5280802;
CompTox Dashboard (EPA)	DTXSID201016569 ;
	InChI InChI=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+ Key: CDICDSOGTRCHMG-ONEGZZNKSA-N;
	SMILES COC1=CC(=CC(=C1O)OC)/C=C/C=O;
Properties
Chemical formula	C11H12O4
Molar mass	208.213 g·mol−1
Melting point	104 to 106 °C (219 to 223 °F; 377 to 379 K)
log P	1.686
Acidity (pKa)	9.667
Basicity (pKb)	4.330
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Related compounds
Related alkenals	Cinnamaldehyde; Coniferyl aldehyde; DMACA reagent; 2-Nitrocinnamaldehyde
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Sinapaldehyde is an organic compound with the formula HO(CH₃O)₂C₆H₂CH=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.^[3]^[4]

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.^[5]

Sinapaldehyde is reduced to the alcohol by the action of dehydrogenase enzymes.^[4] In Arabidopsis thaliana, the enzyme dihydroflavonol 4-reductase uses NADP⁺ to reduce sinapaldehyde to sinapyl alcohol.^[6]

It is found in Senra incana (Hibisceae). It is a low molecular weight phenol that is susceptible to extraction from cork stoppers into wine.^[7]

^ "AC1L3OEQ - Compound Summary". The PubChem Project. USA: National Center for Biotechnology Information.
^ "C&L Inventory". www.echa.europa.eu.
^ 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
^ ^a ^b Li, Laigeng; Cheng, Xiao Fei; Leshkevich, Jacqueline; Umezawa, Toshiaki; Harding, Scott A.; Chiang, Vincent L. (2001). "The Last Step of Syringyl Monolignol Biosynthesis in Angiosperms is Regulated by a Novel Gene Encoding Sinapyl Alcohol Dehydrogenase". The Plant Cell. 13 (7): 1567–1586. doi:10.1105/tpc.010111. PMC 139549. PMID 11449052.
^ Osakabe, Keishi; Tsao, Cheng Chung; Li, Laigeng; Popko, Jacqueline L.; Umezawa, Toshiaki; Carraway, Daniel T.; Smeltzer, Richard H.; Joshi, Chandrashekhar P.; Chiang, Vincent L. (1999). "Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms". Proceedings of the National Academy of Sciences. 96 (16): 8955–8960. Bibcode:1999PNAS...96.8955O. doi:10.1073/pnas.96.16.8955. PMC 17714. PMID 10430877.
^ Dihydroflavonol 4-reductase on arabidopsisreactome.org
^ 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