Propyl gallate, or propyl 3,4,5-trihydroxybenzoate is an ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 formed by the condensation

Condensation

Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition....

 of 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...

 and propanol

Propan-1-ol

1-Propanol is a primary alcohol with the molecular formula of C3H8O, and a structural formula of CH3CH2CH2OH. It is also known as propan-1-ol, 1-propyl alcohol, n-propyl alcohol, n-propanol, or simply propanol. It is an isomer of isopropanol . It is used as a solvent in the pharmaceutical...

. Since 1948, this 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...

 has been added to foods containing oils and fats to prevent oxidation. As a food additive, it is used under the E number

E number

E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...

 E310.

Description

Propyl gallate is an anti-oxidant. It protects against oxidation by hydrogen peroxide and oxygen free radicals.

Uses

Propyl gallate is used to protect oils and fats in products from oxidation.

It is used in foods, cosmetics, hair products, adhesives, and lubricants.

It is used as a triplet state

Triplet state

A spin triplet is a set of three quantum states of a system, each with total spin S = 1 . The system could consist of a single elementary massive spin 1 particle such as a W or Z boson, or be some multiparticle state with total spin angular momentum of one.In physics, spin is the angular momentum...

 quencher

Quenching (fluorescence)

Quenching refers to any process which decreases the fluorescence intensity of a given substance. A variety of processes can result in quenching, such as excited state reactions, energy transfer, complex-formation and collisional quenching. As a consequence, quenching is often heavily dependent on...

 and an 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...

 in fluorescence microscopy

Fluorescence microscope

A fluorescence microscope is an optical microscope used to study properties of organic or inorganic substances using the phenomena of fluorescence and phosphorescence instead of, or in addition to, reflection and absorption...

.

Biological effects

A 2009 study found that propyl gallate acts as an estrogen

Estrogen

Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...

 antagonist

Receptor antagonist

A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...

.