p-Coumaric acid

p-Coumaric acid

Skeletal formula of p-coumaric acid
Ball-and-stick model of p-coumaric acid
Names
Preferred IUPAC name (2E)-3-(4-Hydroxyphenyl)prop-2-enoic acid
Other names (E)-3-(4-Hydroxyphenyl)-2-propenoic acid (E)-3-(4-Hydroxyphenyl)acrylic acid para-Coumaric acid 4-Hydroxycinnamic acid trans-4-Hydroxycinnamic acid β-(4-Hydroxyphenyl)acrylic acid
Identifiers
CAS Number	501-98-4 checkY
3D model (JSmol)	Interactive image Interactive image
Beilstein Reference	2207383
ChEBI	CHEBI:32374 checkY
ChEMBL	ChEMBL66879 checkY
ChemSpider	553148 checkY
DrugBank	DB04066 checkY
ECHA InfoCard
EC Number	231-000-0
E number
Gmelin Reference	2245630
IUPHAR/BPS	5787
KEGG	C00811
PubChem CID	637542
UNII	IBS9D1EU3J
CompTox Dashboard (EPA)	{{#property:P3117}}
InChI InChI=1S/C9H8O3/c10-8-4-1-7(2-5-8)3-6-9(11)12/h1-6,10H,(H,11,12)/b6-3+ checkY Key: NGSWKAQJJWESNS-ZZXKWVIFSA-N checkY InChI=1/C9H8O3/c10-8-4-1-7(2-5-8)3-6-9(11)12/h1-6,10H,(H,11, 12)/b6-3+/f/h11H InChI=1/C9H8O3/c10-8-4-1-7(2-5-8)3-6-9(11)12/h1-6,10H,(H,11,12)/b6-3+ Key: NGSWKAQJJWESNS-ZZXKWVIFBJ
SMILES C1=CC(=CC=C1\C=C\C(=O)O)O c1cc(ccc1/C=C/C(=O)O)O
Properties
Chemical formula	C9H8O3
Molar mass	164.160 g·mol−1
Melting point	210 to 213 °C (410 to 415 °F; 483 to 486 K)
Hazards
GHS labelling:
Pictograms	GHS07: Exclamation mark
Signal word	Danger
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P305+P351+P338
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

p-Coumaric acid is an organic compound with the formula HOC₆H₄CH=CHCO₂H. It is one of the three isomers of coumaric acid. It is a white solid that is only slightly soluble in water but very soluble in ethanol and diethyl ether.

Natural occurrences

It is a precursor to many natural products, especially lignols, precursors to the woody mass that comprise many plants. Of the myriad occurrences, p-coumaric acid can be found in Gnetum cleistostachyum.

In food

p-Coumaric acid can be found in a wide variety of edible plants and fungi such as peanuts, navy beans, tomatoes, carrots, basil and garlic. It is found in wine and vinegar. It is also found in barley grain.

p-Coumaric acid from pollen is a constituent of honey.

Derivatives

p-Coumaric acid glucoside can also be found in commercial breads containing flaxseed. Diesters of p-coumaric acid can be found in carnauba wax.

Biosynthesis

It is biosynthesized from cinnamic acid by the action of the P450-dependent enzyme 4-cinnamic acid hydroxylase (C4H).

cinnamic acid  $\begin{array}{c}\\ \stackrel{\mathrm{C}\mathrm{4}\mathrm{H}}{\to }\end{array}$ Error creating thumbnail:

It is also produced from L-tyrosine by the action of tyrosine ammonia lyase (TAL).

L-Tyrosine  $\stackrel{\mathrm{T}\mathrm{A}\mathrm{L}}{\to }$ Error creating thumbnail: + NH₃ + H⁺

Biosynthetic building block

p-Coumaric acid is the precursor of 4-ethylphenol produced by the yeast Brettanomyces in wine. The enzyme cinnamate decarboxylase catalyzes the conversion of p-coumaric acid into 4-vinylphenol. Vinyl phenol reductase then catalyzes the reduction of 4-vinylphenol to 4-ethylphenol. Coumaric acid is sometimes added to microbiological media, enabling the positive identification of Brettanomyces by smell.

File:Coumaric acid to 4-ethyphenol.svg

The conversion of p-coumaric acid to 4-ethyphenol by Brettanomyces

cis-p-Coumarate glucosyltransferase is an enzyme that uses uridine diphosphate glucose and cis-p-coumarate to produce 4′-O-β-D-glucosyl-cis-p-coumarate and uridine diphosphate (UDP). This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases.

Phloretic acid, found in the rumen of sheep fed with dried grass, is produced by hydrogenation of the 2-propenoic side chain of p-coumaric acid.

The enzyme, resveratrol synthase, also known as stilbene synthase, catalyzes the synthesis of resveratrol ultimately from a tetraketide derived from 4-coumaroyl CoA.

p-Coumaric acid is a cofactor of photoactive yellow proteins (PYP), a homologous group of proteins found in many eubacteria.

p-Coumaric acid is found as the base moiety of caleicine, one of many sesquiterpenes in Calea ternifolia.

See also

• o-coumaric acid
• m-coumaric acid
• Coumarin
• Coumaroyl-Coenzyme A
• Ferulic acid
• Cinnamic acid
• Phenolic content in wine
• p-Coumaroylated anthocyanins