Syringic acid explained

Syringic acid is a naturally occurring phenolic compound and dimethoxybenzene that is commonly found as a plant metabolite.

Natural occurrence

Syringic acid can be found in several plants including Ardisia elliptica and Schumannianthus dichotomus.^[1] It is biosynthesized by the shikimic acid pathway in plants.

Synthesis

Syringic acid can be prepared by selectively hydrolyzing (demethylating) eudesmic acid with 20% sulfuric acid.^[2]

Presence in food

Syringic acid can be found in several fruits including olives, dates, spices, pumpkin, grapes,^[3] acai palm,^[4] honey, red wine, among others.^[5] Its presence in the ancient Egyptian drink shedeh could confirm it was made out of grape, as syringic acid is released by the breakdown of the compound malvidin, also found in red wine. It is also found in vinegar.^[6]

Applications

Various studies have found syringic acid to have potentially useful properties such as anti-oxidant, anti-microbial, anti-inflammation, anti-cancer, and anti-diabetic.

Syringic acid can be enzymatically polymerized. Laccase and peroxidase induced the polymerization of syringic acid to give a poly(1,4-phenylene oxide) bearing a carboxylic acid at one end and a phenolic hydroxyl group at the other.^[7]

See also

• Phenolic content in wine
• Syringol
• Syringaldehyde
• Acetosyringone
• Sinapyl alcohol
• Sinapinic acid
• Sinapaldehyde
• Sinapine
• Canolol

Notes and References

1. Rob. Md. Mahfuzur. Hossen. Kawsar. Iwasaki. Arihiro. Suenaga. Kiyotake. Kato-Noguchi. Hisashi. 2020-01-14. Phytotoxic Activity and Identification of Phytotoxic Substances from Schumannianthus dichotomus. Plants. 9. 1. 102. 10.3390/plants9010102. 31947649. 7020185. 2223-7747. free.
2. Bogert. Marston . Ehrlich, Jacob . The synthesis of certain pyrogallol ethers, including a new acetophenetide derived from the ethyl ether of syringic acid. Journal of the American Chemical Society. Mar 1919. 41. 5. 798–810. 10.1021/ja02226a013. 2 November 2013.
3. Pezzuto. John M.. August 2008. Grapes and Human Health: A Perspective. Journal of Agricultural and Food Chemistry. 56. 16. 6777–6784. 10.1021/jf800898p. 18662007. 0021-8561.
4. J Agric Food Chem . Jun 2008 . 56 . 12 . 4631–4636 . Chemical composition, antioxidant properties, and thermal stability of a phytochemical enriched oil from Acai (Euterpe oleracea Mart.) . Pacheco-Palencia LA, Mertens-Talcott S, Talcott ST . 18522407. 10.1021/jf800161u.
5. Srinivasulu. Cheemanapalli. Ramgopal. Mopuri. Ramanjaneyulu. Golla. Anuradha. C.M.. Suresh Kumar. Chitta. December 2018. Syringic acid (SA) ‒ A Review of Its Occurrence, Biosynthesis, Pharmacological and Industrial Importance. Biomedicine & Pharmacotherapy. 108. 547–557. 10.1016/j.biopha.2018.09.069. 30243088. 0753-3322. free.
6. 10.1007/BF01192948. Analysis of polyphenolic compounds of different vinegar samples. 1994. Gálvez . Miguel Carrero. Barroso. Carmelo García . Pérez-Bustamante. Juan Antonio. Zeitschrift für Lebensmittel-Untersuchung und -Forschung. 199. 29–31. 91784893.
7. Book: 10.1021/bk-2000-0764.ch009 . Enzymatic Polymerization of Natural Phenol Derivatives and Enzymatic Synthesis of Polyesters from Vinyl Esters . Polymers from Renewable Resources . ACS Symposium Series . 2001 . Uyama . Hiroshi . Ikeda . Ryohei . Yaguchi . Shigeru . Kobayashi . Shiro . 0-8412-3646-1 . 764 . 113 .