Page 128 - phytochemistry II -pharmD general

True tannins Condensed tannins
Hydrolysable tannins (Phlobatannins)

Liability for Can be hydrolyzed by More resistant to hydrolysis
hydrolysis
acids or enzymes to give or breakage.
Effect of dry
distillation phenolic acids (gallic or But on prolonged heating
Examples
ellagic) and glucose, with acids, they polymerize
FeCl3 test
So, they are Called (Or decompose) yielding

‘‘phenolic acid red insoluble pigment

glycosides’’ ‘’phlopaphanes’’

Formation of pyrogallol Formation of catechol

Gallotannins in clove EGCG in tea
Ellagitannins in Green colour
pomegranate

Blue colour

GOOD LUCK

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