3. BLACK CATECHU
Synonyms
o Cutch,
o black catechu,
o kattha.
Biological source
o It is the dried aqueous extract
prepared from the heartwooof
Acacia catechu Willdenow,
belonging to family
Leguminosae.
4. Morphology
o Colour: Black or brownish black mass.
o Odour: Odourless Astringent and
subsequently sweet taste.
o Size:Irregular mass.
o Extra features: Outer surface is firm and
brittle. When broken the fractured
surface appears glassy with small
cavities.
5. Chemical constituents
10% Acacatechin. Also called as Acacia
catechin Undergoes to give
catechutannic acid.
Catechu red, quercetin, gum ,
quercitrin.
Does not contain chlorophyll and also the
fluorescent substance present in Pale
catechu.
Catechol
Catechin
6. Chemical tests
o With Ferric Chloride solution, it gives
Bluish-black colour.
o With Vanillin and Hydrochloric acid
Black Catechu gives Pink or Red
colour.
o Aqueous solution of Black Catechu
with Lime Water gives Brown colour.
7. Therapeutic uses
o Cutch is used in medicine as astringent. It
cures troubles of mouth, diseases of the
throat and diarrhoea. It also increases
appetite. In India and eastern countries, it is
used in betel leaves for chewing. In dyeing
industries, cutch used for dyeing fabrics
brown or black.
8. PALE CATECHU
Synonyms
o Gambier,
o Catechu,
o Gambir.
Biological source
o Gambier or pale catechu is a dried
aqueous extract produced from the leaves
and young twigs/shoots of Uncaria
gambier Roxburgh. belonging to family
Rubiaceae.
9. Morphology
o Colour: Dull reddish brown colour externally
and pale brownto buff colour internally.
o Odour: Odourless
o Taste: At first it is bitter and astringent but
later it is sweet.
o Shape: strips, flakes or coarse powder
o Size: pale catechu comes in the form of
cubes orrectangular blocks of 2 to 4 cm
length
o Shape: Regular cubes or as rectangular
blocks..
10. Chemical constituents
o Reddish brown coloured,
o Condensed tannins in the
form of catechins (7-33%).
o Catechutannic acid (22-50%),
and Catechu red.
o Contains quercetin and
gambier fluorescin.
11. Chemical tests(Gambier Fluorescin test)
Alcoholic extract of Gambier
Filtered then collect the filtrate
To the filtrate add NaOH with shaking
Petrolium ether is added & stands for few
minutes
Green colour fluorescence is observed
12. Therapeutic uses
o Used as Astringent.
o Source of tannic acid
o Used in Leather & Fabric industry
o Used in dyeing industry