YOU ARE HERE: PharmaXChange.info > Pharmacognosy > Tannins
CHECK OUT THE NEW PHARMAXCHANGE.INFO TO FIND THE LATEST ON TOPICS. EARN POINTS TO POST YOUR CONTENT WHICH CAN BE REDEEMED FOR PRIZES.
Tannins
Author: Unknown
Description: Here are some class notes of tannin containing drugs. The file includes monographs of condensed tannins (black catechu, pale catechu and kinos), hydrolysable tannins (galls, myrobalon, bahera and hazel nut), and pseudo tannins (coffee and tea)
Number of Pages: 7 pages

CLICK HERE TO VIEW THE FULL NOTES ON TANNINS IN PDF FORMAT

PREVIEW

TANNINS

Author: Unkown


Tannins are secondary metabolites of plants, non-nitrogenous, phenolic in nature.
They have a property to tan animal skin to convert to leather or hide.
Conversion imparts resistance to water, heat, abrasives.
They can be extracted using water-acetone/alcohol mixture.
They have a property to precipitate gelatin & heavy metals.

Complex tannins are macro molecules with many sugar molecules.

3 major classes of tannins are:
hydrolysable tannins
non-hydrolysable tannins (condensed tannins)
pseudo tannins
Hydrolysable tannins on heating with hydrochloric or sulphuric acids yield gallic or ellagic acids
Eg- myrobalon, bahera, witch hazel
Non-hydrolysable tannins on heating with hydrochloric acid yield phlobaphenes like phloroglucinol
Eg- black catechu, pale catechu, kinos
Pseudo tannins are low molecular weight compounds associated with other compounds. They do not answer gold beater skin test unlike hydrolysable and condensed tannins.

Eg- tea, coffee

They have catechins which give rise to the peculiar odour.

Gold beater skin test:
When gold beater skin or ox skin is dipped in HCl & treated with 1% FeSO4
solution, after washing with water it gives a blue / black colour.


CONDENSED TANNINS:

BLACK CATECHU

BIOLOGICAL SOURCE -. Heart wood of acacia catechu / acacia chundra
Family- leguminosae

Preparation:
Pieces of heartwood are boiled with water till the drug is exhausted & the resulting
solution is stored in clay pits wherein the semi solid mass known as cutch gets
absorbed & the liquid remaining behind is dried & cut into small pieces.

Chemical Constituents:
Contains acacia catechin & quercetin

 

CLICK HERE TO VIEW THE FULL NOTES ON TANNINS IN PDF FORMAT




 

CHECK OUT THE NEW PHARMAXCHANGE.INFO TO FIND THE LATEST ON TOPICS. EARN POINTS TO POST YOUR CONTENT WHICH CAN BE REDEEMED FOR PRIZES

sidepanel

TO VIEW PDF FILES

Get Adobe Reader
TO VIEW FLASH FILES
Get Adobe Flash Player


PARTNER SITES

 

PharmaXChange.info © copyright 2007
Created by: Akul Mehta