Page 154 - Pharmacognosy-II (06-PG 303)

Extracts
3.Gambier
Pale catechu ‫فوفل هندي‬

Botanical origin: It is the dried aqueous extract prepared from the dried leaves
and twigs of Uncaria gambier family rubiaceae.
It has the form of reddish brown cubes, odorless, with astringent bitter taste
followed by sweetness

Constituents:
Catechin, catechutannic acid, gambier fluorescin.

Chemical tests:
1. Microscopical: yellowish brown acicular catechin crystals
2. When few drops of FeCl3 solution are added to an aqueous solution an
intense green color is formed (due to condensed tannins).
3. Test for gambier fluorescin:
• Warm 0.3 g with 2 ml of ethanol , cool and filter. Add 2 ml of 5M sodium
hydroxide to the filtrate, shake, add 2 ml of petroleum spirit, shake and
allow to separate. A brilliant greenish fluorescence is produced in the
upper layer.
4. Test for catechins (formation of phloroglucinol):
• Dip match-stick or a piece of wood in an alcoholic extract of the drug, dry,
dip in HCl, a magenta red color is formed.

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