Tannins drugs

2. CATECHU
Synonyms – Pale catechu, gambier, kattha
Biological source – It consists of the dried
aqueous extract prepared from the leaves of
Uncaria gambier
Family - Rubiaceae

3. Chemical constituents –
It contains tannins like catechins and
catechu tannic acid
It contains flavonoids like quercetin and
fluorescent substances Gambier fluorescein.
It also contains catechu- red, pyrogallol, fixed
oil and waxes

4. Uses –
Used as an astringent
Used in the treatment of diarrhoea
Used in the preparation of lozenges

5. BLACK CATECHU
Biological source –
It consists of the dried aqueous extract
prepared from heart wood of Acacia catechu
and Acacia chundra
Family - Leguminosae

6. Chemical constituents –
It contains tannins like catechins and catechu
tannic acid
It contains flavonoids like quercetin.
Others like Catechu- red and gum
Uses –
Used as an astringent, used in diarrhoea
Used as a cooling and digestive agent

7. CHEMICAL TESTS FOR CATECHU
1. Gambir Fluorescin test-
Alcoholic extract of drug, few drops of
sodium hydroxide mix and add petroleum
ether, shake and kept aside for few minutes
– petroleum ether layer shows green
fluorescence ( + ve for pale catechu due
Gambir Fluorescin )

8. 2. Match stick test ( Catechins test) –
A match stick is dipped in aqueous plant
extract , dried near burner and moistened
with Hcl. On warming near flame , the
match stick wood turns pink or red due to
the formation of phloroglucinol.

9. 3. Vanillin – Hydrochloric acid test –
Test solution and few drops of Vanillin –
Hydrochloric acid reagent – A red or pink is
formed due the formation of phloroglucinol.
4. Chlorophyll test -
Powdered drug is heated with chloroform on a
water bath for 1-2 minutes .The organic layer
is filtered in a china dish and evaporated on
the water bath– green residue

10. TANNIC ACID
Biological source –
It is obtained from the nutgalls. Galls are
vegetable outgrowths found on the young
twigs of Quercus infectoria
Family - Fagaceae
Tannic acid is a hydrolysable tannin and
yields Gallic acid and glucose on hydrolysis

11. Uses –
Used as an astringent
Used externally in the treatment of burns
Used as an antidote for alkaloid poisoning

12. NUTGALL
Synonym – Turkey galls
Biological source – Galls are the pathological
outgrowths formed on the twigs of the oak
tree Quercus infectoria
Family - Fagaceae
Chemical constituents – 40-60% of tannic acid
Uses- Used as an astringent, used in the
manufacture of tannic acid

13. QUESTIONS –
Define tannins and explain various methods of estimation
of tannins.10 M
Write a note on general properties and method of isolation
of tannins. 10M
Write the source, active constituents and uses of Catechu
and Nutgall.5M
Explain the different types of tannins with examples.5M
Write a note on Goldbeaters’ test and its significances.5M


14. Write a note on estimation of Hydrolysable tannins.5M
Give the chemical tests for the identification of Catechu
and Tannic acid.5M
Give an account of Catechu.5M
What are tannins? Give general chemical tests to identify
them.5M
Define Tannins. How will you differentiate True tannins
from pseudo tannins ? 5M

15. Write in brief about Nut gall. 2M
Chemical tests for the identification of tannins.2M
What is tannic acid and give its uses.2M
Gambir- Flurorescin test and its significances.2M
Define Pseudo- tannins and give examples. 2M