Sinapaldehyde is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula HO(CH₃O)₂C₆H₂CH=CHCHO. It is a derivative of

cinnamaldehyde Cinnamaldehyde is an organic compound with the formula or . Occurring naturally as predominantly the ''trans'' (''E'') isomer, it gives cinnamon its flavor and odor. It is a phenylpropanoid that is naturally synthesized by the shikimate pathway ...

, featuring one

hydroxy group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

and two

methoxy group In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula . On a benzene ring, the Hammett equation classifies a methoxy substituent at the ''para'' position a ...

s as

substituent In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...

s. It is an intermediate in the formation of

sinapyl alcohol Sinapyl alcohol is an organic compound structurally related to cinnamic acid. It is biosynthetized via the phenylpropanoid biochemical pathway, its immediate precursor being sinapaldehyde. This phytochemical is one of the monolignols, which a ...

, a lignol that is a major precursor to

lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidit ...

Biosynthetic role

In sweetgum (''

Liquidambar styraciflua ''Liquidambar styraciflua'', commonly known as the American sweetgum among other names, is a deciduous tree in the genus ''Liquidambar'' native to warm temperate areas of eastern North America and tropical montane regions of Mexico and Central A ...

''), sinapaldehyde arises in two steps from

coniferyl aldehyde Coniferyl aldehyde is an organic compound with the formula HO(CH3O)C6H3CH=CHCHO. It is a derivative of cinnamaldehyde, featuring 4-hydroxy and 3-methoxy substituents. It is a major precursor to lignin. Biosynthetic role In sweetgum (''Liquidamba ...

beginning with

hydroxylation In chemistry, hydroxylation refers to the installation of a hydroxyl group () into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility ...

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 A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyze reverse as well as ...

enzymes. In ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally ...

'', the enzyme

dihydroflavonol 4-reductase In enzymology, a dihydrokaempferol 4-reductase () is an enzyme that catalyzes the chemical reaction :cis-3,4-leucopelargonidin + NADP+ \rightleftharpoons (+)- dihydrokaempferol + NADPH + H+ Thus, the two substrates of this enzyme are cis-3,4 ...

uses NADP⁺ to reduce sinapaldehyde to sinapyl alcohol. It is found in ''

Senra incana ''Senra incana'' is a flowering plant species in the genus ''Senra''. The plant produces the phenolic compounds coniferaldehyde, scopoletin, sinapaldehyde and syringaldehyde Syringaldehyde is an organic compound that occurs in trace amounts w ...

'' (Hibisceae). It is a low molecular weight

phenol Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire. The molecule consists of a phenyl group () ...

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

References

{{Reflist Natural phenols Aldehydes O-methylated phenylpropanoids

Biosynthetic role

See also

References