Sinapaldehyde
# Sinapaldehyde

Sinapaldehyde is an organic compound with the formula $HO(CH_3O)_2C_6H_2CH=CHCHO.$ 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.

## 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.

