Useful for pharmacy students

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