Page 99 - Pharmd general phytochemistry I-Final2024_LEUCTERS

 Dry distillation of hydrolyzable tannins gives pyrogallol

Condensed tannins:

 These are more resistant to hydrolysis or breakage, upon
prolonged heating with acids, they undergo decomposition (not
hydrolyses) to give a red soluble compound(phlobaphane).

 Condensed tannins are derived from Catechin and flavan, 3,4-diol.
 Dry distillation of condensed tannins gives catechol. That is why

these two classes were named pyrogallol tannins and catechol
tannins, respectively.
Properties:

 Polar compounds soluble in water, alcohol.
 Insoluble in organic solvent.
 Have the ability of precipitating soluble proteins (gelatin)
 True tannins combine with animal hide protein thus converting hide into

leather (process of tanning) commercial significance

 True tannins, combine with animal hide protein thus converting hide into

leather (Process of tanning). This property, being of commercial
significance, is made use of for testing for true tannins (Higher molecular
weight tannins).

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