Phenolic acid
Encyclopedia
Phenolic acids are a type of organic compounds. Included in that class are substances containing a phenol
ic ring and an organic carboxylic acid
function (C6-C1 skeleton).
Different categories are made of monohydroxybenzoic acids (paraben, methyl paraben, propyl paraben
), dihydroxybenzoic acid
s (gentisic acid, protocatechuic acid), trihydroxybenzoic acid
s (gallic acid, phloroglucinol carboxylic acid). This type of phenolic acids (especially gallic acid
) is a component of hydrolysable tannin
s.
Syringic acid
, eudesmic acid
or salicylic acid
are other phenolic acids.
Phenolic acid can be found in many plant species. Their content in dried fruit
s can be high.
Many phenolic acids can be found in human urine. It is also a part of the humic substances
, which are the major organic constituents of soil humus.
Phenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
ic ring and an organic carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
function (C6-C1 skeleton).
Different categories are made of monohydroxybenzoic acids (paraben, methyl paraben, propyl paraben
Propyl paraben
Propylparaben, the propyl ester of p-hydroxybenzoic acid, occurs as a natural substance found in many plants and some insects, although it is manufactured synthetically for use in cosmetics, pharmaceuticals and foods. It is a preservative typically found in many water-based cosmetics, such as...
), dihydroxybenzoic acid
Dihydroxybenzoic acid
Dihydroxybenzoic acids are a type of phenolic acids.There are six main compounds, having all the same molecular formula C7H6O4. Those are:* 2,3-Dihydroxybenzoic acid * 2,4-Dihydroxybenzoic acid...
s (gentisic acid, protocatechuic acid), trihydroxybenzoic acid
Trihydroxybenzoic acid
Trihydroxybenzoic acid may refer to the following phenolic acids :* Gallic acid * Phloroglucinol carboxylic acid O-methylated trihydroxybenzoic acids are :* Eudesmic acid* Syringic acid...
s (gallic acid, phloroglucinol carboxylic acid). This type of phenolic acids (especially gallic acid
Gallic acid
Gallic acid is a trihydroxybenzoic acid, a type of phenolic acid, a type of organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H23COOH. Gallic acid is found both free and as part of...
) is a component of hydrolysable tannin
Hydrolysable tannin
A hydrolyzable tannin or pyrogallol-type tannin is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids....
s.
Syringic acid
Syringic acid
Syringic acid is a naturally occurring O-methylated trihydroxybenzoic acid, a type of chemical compound. It can be found in the açaí palm and its oil , in Ardisia elliptica...
, eudesmic acid
Eudesmic acid
Eudesmic acid is an O-methylated trihydroxybenzoic acid. It can be found in Eucalyptus spp....
or salicylic acid
Salicylic acid
Salicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
are other phenolic acids.
Phenolic acid can be found in many plant species. Their content in dried fruit
Dried fruit
Dried fruit is fruit where the majority of the original water content has been removed either naturally, through sun drying, or through the use of specialized dryers or dehydrators. Dried fruit has a long tradition of use dating back to the fourth millennium BC in Mesopotamia, and is prized...
s can be high.
Many phenolic acids can be found in human urine. It is also a part of the humic substances
Humic acid
Humic acid is a principal component of humic substances, which are the major organic constituents of soil , peat, coal, many upland streams, dystrophic lakes, and ocean water. It is produced by biodegradation of dead organic matter...
, which are the major organic constituents of soil humus.
See also
- Benzoic acidBenzoic acidBenzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...
- List of phytochemicals in food
- hydroxycinnamic acidHydroxycinnamic acidHydroxycinnamic 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...
s, molecules with the C6-C3 skeleton