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]

See also

References

  1. ^ "AC1L3OEQ - Compound Summary". The PubChem Project. USA: National Center for Biotechnology Information.
  2. ^ "C&L Inventory". www.echa.europa.eu.
  3. ^ 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
  4. ^ 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.
  5. ^ 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.
  6. ^ Dihydroflavonol 4-reductase on arabidopsisreactome.org
  7. ^ 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