plant extracts - gallic acid

[Michaelwet]

Tannic acid is a specific form of tannin, a keyboard of polyphenol. Its weak acidity (pKa all 6) is rightful to the numerous phenol groups in the structure. The chemical prescription on commercial tannic acid is time after time specified as C76H52O46, which corresponds with decagalloyl glucose, but in fact it is a mixture of polygalloyl glucoses or polygalloyl quinic acid esters with the horde of galloyl moieties per molecule ranging from 2 up to 12 depending on the plant start used to extort the tannic acid. Commercial tannic acid is usually extracted from any of the following weed parts: Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or Quercus infectoria or Sicilian sumac leaves (Rhus coriaria).

According to the definitions provided in apparent references such as cosmopolitan pharmacopoeia, Edibles Chemicals Codex and FAO-WHO tannic acid monograph one tannins sourced from the above-mentioned plants can be considered as tannic acid. Every now extracts from chestnut or oak wood are also described as tannic acid but this is an incorrect expend of the term. It is a yellow to be disclosed brown amorphous powder.