Syringic acid is a naturally occurring

phenolic compound In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ar ...

and dimethoxybenzene that is commonly found as a plant metabolite.

Natural occurrence

Syringic acid can be found in several plants including ''

Ardisia elliptica ''Ardisia elliptica'' is an evergreen tree, also known as the shoebutton ardisia, duck's eye and coralberry, native to the west coast of India, Sri Lanka, Indochina, Malaysia, Indonesia and New Guinea. It is a prolific reproducer which has made i ...

'' and '' Schumannianthus dichotomus''.

Synthesis

Syringic acid can be prepared by selectively hydrolyzing ( demethylating) eudesmic acid with 20%

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

Presence in food

Syringic acid can be found in several fruits including olives, dates, spices, pumpkin, grapes, acai palm, honey, red wine, among others. Its presence in the ancient Egyptian drink

shedeh Shedeh was a drink of ancient Egypt. Although it was long thought to have been made from pomegranates, recent evidence suggests it came from red grapes. History The name Shedeh appeared inscribed on the labels of Egyptian two-handled pottery amp ...

could confirm it was made out of grape, as syringic acid is released by the breakdown of the compound

malvidin Malvidin is an O-methylated anthocyanidin, the 3',5'-methoxy derivative of delphinidin. As a primary plant pigment, its glycosides are highly abundant in nature. Natural occurrences Malvidin is responsible for the blue color found in petals ...

, also found in

red wine Red wine is a type of wine made from dark-colored grape varieties. The color of the wine can range from intense violet, typical of young wines, through to brick red for mature wines and brown for older red wines. The juice from most purple gr ...

. It is also found in

vinegar Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to eth ...

Applications

Various studies have found syringic acid to exhibit useful pharmaceutical properties such as

anti-oxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, ...

anti-microbial An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ...

anti-inflammation Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as op ...

, anti-cancer, and

anti-diabetic Drugs used in diabetes treat diabetes mellitus by altering the glucose level in the blood. With the exceptions of insulin, most GLP receptor agonists (liraglutide, exenatide, and others), and pramlintide, all are administered orally and are thu ...

. Syringic acid can be

enzymatically Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

polymerised.

Laccase Laccases () are multicopper oxidases found in plants, fungi, and bacteria. Laccases oxidize a variety of phenolic substrates, performing one-electron oxidations, leading to crosslinking. For example, laccases play a role in the formation of l ...

and

peroxidase Peroxidases or peroxide reductases ( EC numberbr>1.11.1.x are a large group of enzymes which play a role in various biological processes. They are named after the fact that they commonly break up peroxides. Functionality Peroxidases typically ca ...

induced the polymerization of syringic acid to give a

poly(1,4-phenylene oxide) Poly(''p''-phenylene oxide) (PPO), poly(''p''-phenylene ether) (PPE), often referred to simply as polyphenylene oxide, is a high-temperature thermoplastic. It is rarely used in its pure form due to difficulties in processing. It is mainly used as ...

bearing a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxyli ...

at one end and a

phenol Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it r ...

ic hydroxyl group at the other.

References

{{Progestogenics Trihydroxybenzoic acids O-methylated natural phenols Progestogens

Natural occurrence

Synthesis

Presence in food

Applications

See also

References