4-Hydroxyphenylacetaldehyde

4-Hydroxyphenylacetaldehyde, also known as p-hydroxyphenylacetaldehyde, is a natural product with the formula HOC₆H₄CH₂CHO. It is a derivative of phenylacetaldehyde and occurs as a white solid at room temperature.^[1]

4-Hydroxyphenylacetaldehyde

Names
Preferred IUPAC name (4-Hydroxyphenyl)acetaldehyde
Other names p-Hydroxyphenylacetaldehyde
Identifiers
CAS Number	7339-87-9 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:15621
ChemSpider	389113
ECHA InfoCard	100.216.847
EC Number	689-849-1
KEGG	C03765
PubChem CID	440113
UNII	HDJ7B4KB3X Y
CompTox Dashboard (EPA)	DTXSID00223631
InChI InChI=1S/C8H8O2/c9-6-5-7-1-3-8(10)4-2-7/h1-4,6,10H,5H2 Key: IPRPPFIAVHPVJH-UHFFFAOYSA-N
SMILES C1=CC(=CC=C1CC=O)O
Properties
Chemical formula	C8H8O2
Molar mass	136.150 g·mol−1
Appearance	White solid
Melting point	118 °C (244 °F; 391 K)
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P322, P330, P332+P313, P337+P313, P362, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

4-Hydroxyphenylacetaldehyde can be synthesized from (L-tyrosine) via a parsley tyrosine decarboxylase.^[2]

Occurrence

4-Hydroxyphenylacetaldehyde is produced from the metabolism of tyramine by monoamine oxidase (MAO) enzymes in humans and the tyramine oxidase (tynA) enzyme in Escherichia coli.^[3][4] In both species, it is subsequently metabolized into 4-hydroxyphenylacetate by aldehyde dehydrogenase (ALDH) enzymes in humans and the phenylacetaldehyde dehydrogenase (feaB) enzyme in E. coli.^[3][4][5]

The condensation of 4-hydroxyphenylacetaldehyde and dopamine is a key step in the biosynthesis of benzylisoquinoline alkaloids. These natural products include berberine and morphine.^[6]