Gallic acid

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Gallic acid
IUPAC name
Other names Gallic acid
Identifiers
CAS number [[149-91-7 (Anhydrous)
[5995-86-8] (Monohydrate) [149-91-7] (Anhydrous)
[5995-86-8] (Monohydrate)]
]
SMILES
Properties
Molecular formula C7H6O5
Molar mass 170.12 g/mol
Appearance White, yellowish-white, or
pale fawn-colored crystals.
Density 1.7 g/cm3 (anhydrous)
Melting point

250 °C, 523 K, 482 °F

Solubility in water 1.1 g/100 ml water @ 20° C (anhydrous)
1.5 g/100 ml water @ 20 °C (monohydrate)
Acidity (pKa) COOH: 4.5, OH: 10.
Hazards
MSDS External MSDS
Main hazards Irritant
Related compounds
Related compounds Benzoic acid, Phenol, Pyrogallol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox references

Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants.[1] The chemical formula is C6H2(OH)3COOH. Gallic acid is found both free and as part of tannins. Salts and esters of gallic acid are termed gallates. Despite its name, it does not contain gallium.

Gallic acid is commonly used in the pharmaceutical industry.[2] It is used as a standard for determining the phenol content of various analytes by the Folin-Ciocalteau assay; results are reported in gallic acid equivalents.[3] Gallic acid can also be used as a starting material in the synthesis of the hallucinogenic alkaloid mescaline.[4]

Gallic acid was one of the substances used by Angelo Mai among other early investigators of palimpsests to clear the top layer of text off and reveal hidden manuscripts underneath. Mai was the first to employ it, but did so "with a heavy hand," often damaging manuscripts for future study.[citation needed]

"Gallic acid seems to have anti-fungal and anti-viral properties. Gallic acid acts as a antioxidant and helps to protect our cells against oxidative damage. Gallic acid was found to show cytotoxicity against cancer cells, without harming healthy cells. Gallic acid is used as a remote astringent in cases of internal haemorrhage. Gallic acid is also used to treat albuminuria and diabetes. Some ointment to treat psoriasis and external haemorrhoids contain gallic acid."[5]

Contents

[edit] List of plants that contain the chemical

[edit] See also

[edit] References

  1. ^ LD Reynolds and NG Wilson, “Scribes and Scholars” 3rd Ed. Oxford: 1991. pp193–4.
  2. ^ S. M. Fiuza. "Phenolic acid derivatives with potential anticancer properties––a structure–activity relationship study. Part 1: Methyl, propyl and octyl esters of caffeic and gallic acids". Elsevier. http://dx.doi.org/10.1016/j.bmc.2004.04.026. 
  3. ^ Andrew Waterhouse. "Folin-Ciocalteau Micro Method for Total Phenol in Wine". UC Davis. http://waterhouse.ucdavis.edu/phenol/folinmicro.htm. 
  4. ^ Tsao, Makepeasce (July 1951). "A New Synthesis Of Mescaline". Journal of the American Chemical Society 73 (11): 5495-5496. ISSN 0002-7863. 
  5. ^ phytochemicals.info
  6. ^ Pathak, S. B. et al. (2004). "TLC Densitometric Method for the Quantification of Eugenol and Gallic Acid in Clove". Chromatographia 60 (3 - 4): 241 - 244. doi:10.1365/s10337-004-0373-y. 

[edit] External links

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