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发表于 2021-7-16 14:33:23
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plant extracts - gallic acid
Tannic acid is a identified with cast of tannin, a category of polyphenol. Its frangible acidity (pKa around 6) is rightful to the numerous phenol groups in the structure. The chemical prescription as a service to commercial tannic acid is again given as C76H52O46, which corresponds with decagalloyl glucose, but in in reality it is a hodgepodge 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 insinuate documentation 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 extraneous references such as ecumenical pharmacopoeia, Edibles Chemicals Codex and FAO-WHO tannic acid paper one tannins sourced from the above-mentioned plants can be considered as tannic acid. Sometimes extracts from chestnut or oak wood are also described as tannic acid but this is an mistaken expend of the term. It is a yellow to light brown amorphous powder. |
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