Tannins

Question 1

Major action of Tannins and how this occurs physically

Answer 1

Astringent action on skin and mucous membranes
The many hydroxy functional groups react with and cross link both the mucous and epithelial cells of the mucosa, binding them more tightly and rendering them less permeable

Question 2

Subclasses of tannins

Answer 2

Hydrolysable tannins - more water soluble; composed of Gallic acid and/or ellagic acid + 1 or more monosaccharides

Condensed tannins - composed of flavonoids, specifically catechins; include the oligomeric proanthicyanidins (OPCs) as well as larger polymers (polymeric proanthocyanidins)

Complex tannins - molecular combinations of condensed and hydrolysable

Question 3

How long should tannins be taken away from pharmaceutical medication and nutrition supplements to avoid interfering with absorption

Answer 3

Between 2-3 hours

Question 4

A well known herb containing both oligomeric procyanidins and stilbenes

Answer 4

Vitis vinifera

Grape

Question 5

Process of reflex astringency

Answer 5

Mediated via digestive system to other parts of the body, eg respiratory or urinary system, via stimulation of vagal nerve reflex

Question 6

Binding of tannins to other molecules is what sort of interaction

Answer 6

Cross linkage