Coumaric acid is a hydroxycinnamic acid

Hydroxycinnamic acid

Hydroxycinnamic acids are a class of polyphenols having a C6-C3 skeleton. These compounds are hydroxy derivatives of cinnamic acid.In the category of phytochemicals that can be found in food, there are :* Alpha-cyano-4-hydroxycinnamic acid...

, an organic compound that is a hydroxy

Hydroxyl

A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...

 derivative of cinnamic acid

Cinnamic acid

Cinnamic acid is a white crystalline organic acid, which is slightly soluble in water.It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter and is the best indication of its environmental history and post-extraction conditions...

. There are three isomer

Isomer

In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...

s, o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. p-Coumaric acid is the most abundant isomer of the three in nature.

Together with sinapyl alcohol

Sinapyl alcohol

Sinapyl alcohol is an organic compound derived from cinnamic acid. This phytochemical is one of the monolignols. It is biosynthetized via the phenylpropanoid biochemical pathway, its immediate precursor being sinapaldehyde. Sinapyl alcohol is a precursor to lignin or lignans. It is also a...

 and coniferyl alcohol

Coniferyl alcohol

Coniferyl alcohol is an organic compound. This colourless crystalline solid is a phytochemical, one of the monolignols. It is synthethized via the phenylpropanoid biochemical pathway. When copolymerized with related aromatic compounds, coniferyl alcohol forms lignin or lignans...

s, p-coumaric acid is a major component of lignocellulose. It is biosynthesized from cinnamic acid

Cinnamic acid

Cinnamic acid is a white crystalline organic acid, which is slightly soluble in water.It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter and is the best indication of its environmental history and post-extraction conditions...

 by the action of the P450-dependent enzyme 4-cinnamic acid hydroxylase.

p-Coumaric acid can be found in a wide variety of edible plants such as peanut

Peanut

The peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...

s, tomato

Tomato

The word "tomato" may refer to the plant or the edible, typically red, fruit which it bears. Originating in South America, the tomato was spread around the world following the Spanish colonization of the Americas, and its many varieties are now widely grown, often in greenhouses in cooler...

es, carrot

Carrot

The carrot is a root vegetable, usually orange in colour, though purple, red, white, and yellow varieties exist. It has a crisp texture when fresh...

s, and garlic

Garlic

Allium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, and rakkyo. Dating back over 6,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent...

. It is a crystalline solid that is slightly soluble in water, but well soluble in ethanol

Ethanol

Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 and diethyl ether

Diethyl ether

Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...

.

p-Coumaric acid has antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

 properties and is believed to reduce the risk of stomach cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 by reducing the formation of carcinogenic nitrosamine

Nitrosamine

Nitrosamines are chemical compounds of the chemical structure R1N-N=O, some of which are carcinogenic.-Usages:Nitrosamines are used in manufacture of some cosmetics, pesticides, and in most rubber products. -Occurrences:...

s.

Biochemistry

p-Coumaric acid is the precursor of 4-ethylphenol

4-Ethylphenol

4-Ethylphenol, often abbreviated to 4-EP, is a phenolic compound with the molecular formula C8H10O. In wine and beer it is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold it can give the wine aromas described as barnyard, medicinal,...

 produced by the yeast Brettanomyces

Brettanomyces

Brettanomyces is a non-spore forming genus of yeast in the family Saccharomycetaceae, and is often colloquially referred to as "Brett". The genus name Dekkera is used interchangeably with Brettanomyces, as it describes the teleomorph or spore forming form of the yeast. The cellular morphology of...

in wine. The yeast converts this to 4-vinylphenol

4-Vinylphenol

4-Vinylphenol is a phenolic compound found in wine and beer. It is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold, it can give the wine aromas described as barnyard, medicinal, band-aids, and mousy...

 via the enzyme cinnamate decarboxylase. 4-Vinylphenol is further reduced to 4-ethylphenol by the enzyme vinyl phenol reductase. Coumaric acid is sometimes added to microbiological media

Growth medium

A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....

, enabling the positive identification of Brettanomyces by smell.