1. Astringents
Catechu

2. Recap In the last class we learnt about The Monograph of Cinnamon
Its Biological source
Morphological characters
Chemical constituents and
Uses

3. On the completion of this period you would be able to know:
Objectives
On the completion of this period you would be able to know:
ASTRINGENTS
Monographs of BLACK CATECHU
and
PALE CATECHU

4. Astringents Astringents are the substances which precipitate
the proteins by forming complexes
Cause contraction of organic tissue and muscular
living fibres.
Capable of arresting Haemorrhages
Reducing secretions of mucous membrane of stomach and intestine.

5. Astringents Acts as anti-coagulants Anti-perspirants
Anti-microbial agents
Styptic and Antidiarrhoeal agents

6. Astringents Astringents may be vegetable or mineral origins
Vegetable : Tannic acid, Myrobalan, Bahera, Catechu.
Mineral : Salts of Aluminium, Bismuth, Barium, Copper and Zinc.

7. Black Catechu Synonym : Cutch, Katha, Khadir, Khair
Biological Source : Dried aqueous extract prepared from the heartwood of the plant
Acacia catechu
Family : Leguminosae

8. Black Catechu
Geographical Source :
INDIA
BURMA

9. Black Catechu Organoleptic characters: Colour : Light Brown to Black
Odour : None
Taste : Very astringent
Size : About to 5 cm
Shape : Cubes or irregular fragments of broken
Cubes or Brick shaped pieces.

10. Black Catechu Chemical Constituents :
4 to 12% Acacatechin or Acacia catechin
25 to 30% Catechu tannic acid
Catechu red
Quercetin
20 to 30% Gum

11. Black Catechu Chemical tests :
1. With Ferric Chloride solution, it gives Bluish-black colour.
2. With Vanillin and Hydrochloric acid Black Catechu
gives Pink or Red colour.
3. Aqueous solution of Black Catechu with Lime Water
gives Brown colour.

12. Black Catechu Uses : Astringent Digestant Expectorant
Used in Diarrhoea
In lozenges and fishing nets as preservative
In the manufacture of Stencils and Printer inks

13. Synonym : Gambier Catechu
Pale Catechu
Synonym : Gambier Catechu
Biological Source : Dried aqueous extract of
leaves and shoots of
Uncaria gambier
Family : Rubiaceae

14. Pale Catechu
Geographical Source :
Malaysia
Indonesia
Borneo

15. Pale Catechu Organoleptic characters: Odour : None Taste : Astringent
Colour : Reddish – brown
Odour : None
Taste : Astringent
Shape : cubes
Size : Each side of cube is about 2.5cm

16. Pale Catechu Chemical Constituents : 7 - 33% Catechin
22 – 50% Catechu tannic acid
Catechu red
Quercetin
Gambier-fluorescein

17. Pale Catechu Chemical tests :
1. Dip a match-stick in decoction of catechu then dry
in air and again dip it in Con. Hydrochloric acid and
warm it near a burner.
Purple colour

18. Pale Catechu Chemical tests : Green fluorescence
2. Test for Gambier fluorescein :
Extract powered drug with alcohol. To the filtrate
add Sodium hydroxide, shake , add few drops of
light petroleum, shake again and allow to stand
petroleum layer emits
Green fluorescence

19. Pale Catechu Chemical tests :
3. Chloroform extract of the drug in white porcelain
dish shows Greenish-yellow colour due to
Chlorophyll.
2nd and 3rd tests are negative for Black Catechu.

20. Pale Catechu Chemical tests :
4. With Vanillin and HCl, it shows Pink or Red
colour.

21. Pale Catechu Uses Astringent Expectorant
Used in Diarrhoea and in Lozenges
In Dyeing and Tanning industries

22. The monograph Black Catechu
Summary
In this class we learnt about :
The monograph Black Catechu
Consists of dried aqueous extract of heartwood of the plant Acacia catechu
Belongs to the family Leguminosae
Contains Acacatechin as main chemical constituent
Used as Astringent & Digestant.

23. In this class we learnt about
Summary
In this class we learnt about
Pale Catechu
Consists of dried aqueous extract of leaves and shoots of the plant Uncaria gambier
Belongs to the Family Rubiaceae
Contains Catechin and Catechu tannic acid
Used as Astringent.

24. Quiz 1. Black Catechu belongs to the family a. Zingiberaceae
b. Leguminosae
c. Myrtaceae
d. Umbelliferae

25. Quiz 2. Pale Catechu belongs to the family a. Zingiberaceae
b. Leguminosae
c. Myrtaceae
d. Rubiaceae

26. Quiz 3.Pale Catechu is used as a. Anti-pyretic b. Astringent
c. Anti-diabetic
d. Anti-viral

27. Quiz 4. Black Catechu is used as a. Antipyretic b. Astringent
c. Antidiabetic
d. Antiviral

28. Frequently Asked Questions
1. Write the Biological source, Active chemical
constituents and one chemical test of Catechu.
2. Write the differences between Black Catechu and Pale Catechu.