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.Wout Boerjan, John Ralph, Marie Baucher "Lignin Biosynthesis" Annu. Rev. Plant Biol. 2003, vol. 54, pp. 519–46.
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.
Sinapaldehyde is reduced to the alcohol by the action of dehydrogenase enzymes. In Arabidopsis thaliana, the enzyme dihydroflavonol 4-reductase uses NADP+ to reduce sinapaldehyde to sinapyl alcohol.
It is found in Senra incana (Hibisceae). It is a low molecular weight phenol that is susceptible to extraction from cork stoppers into wine.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
See also
Phenolic content in wine Syringaldehyde Syringol Syringic acid Acetosyringone Sinapinic acid Sinapine Canolol
References