Drugs Containing Tannins

Dr. Harish Kakrani, Tannins, CDCP 1

DRUGS CONTAINING DRUGS CONTAINING TANNINSTANNINS

DR. HARISH KAKRANI


PALE CATECHUPALE CATECHU


PALE CATECHUPALE CATECHU SYNONYMS: Gambier, Gambir. BIOLOGICAL SOURCE: It is a dried aqueous extract of the

leaves and young shoots of Uncaria gambier Roxburgh.– Family: Rubiaceae.

GEOGRAPHICAL SOURCE: South-East Asia regions like Arachipelago in Malaysia. Indonesia- Java, Sumatra. Borneo.

CULTIVATION & COLLECTION: Cultivation is carried out in fields upto 170m height. Propagation done by sowing seeds in damp soil. Nursery beds are raised. After 9 months, the seedlings are transplanted in open fields.


PALE CATECHUPALE CATECHU The 1st harvesting is done when the plant reaches a height of 2 m. The plant yields the drug upto 20 yrs. The leaves and young shoots collected are boiled in pot called

Cauldron, made up of wood and with iron bottom, for 3 hrs and decoction obtained is concentrated till it becomesa pasty mass with yellowish- green color.

This mass is moulded in cubes and dried.

DESCRIPTION: External features:

Pale catechu occurs as cuboidal mass, each side of which is 2.5cm. Sometimes cubes are broken or attached to one another. Friable in nature.

Inner surface: porous; color is pale brown to buff. Odour: odourless. Taste: Astringent, but sometimes bitter & later sweet.


PALE CATECHUPALE CATECHU When mounted in water, it shows minute acicular crystals. CHEMICAL CONSTITUENTS:

7 to 33% catechin, which is a structural unit of catechol tannins or phlobatannins.

Catechins: White needle shaped crystals. Soluble in hot water and alcohol. Not real tannin, but psuedotannin.

22 to 50% catechu-tannic acid. It is non-crystalline phloba-tannin. On decomposition, it yields insoluble,dark colored, phlobaphene catechu-red, whichis also present as independent constituent.

Catechu red. Also, quercetin and gambier fluorescin.


PALE CATECHUPALE CATECHU CHEMICAL TESTS:

Sr. No

TEST OBSERVATION INFERENCE

1 Gambier- Fluorescin Test: Boil a little powder drug with alcohol,

filter & add NaOH solution to the filterate, stir & add few ml of light

petroleum.

Petroleum layer shows

green fluorescence

Result due to fluroescine

constituent present in pale catechu.

2 Chlorophyll Test: Boil powder with 5ml. Chloroform on water-bath & filter in white porcelain dish & evaporate in water-bath.

Greenish-yellow residue

Because of chlorophyll present

in the drug.

3 Matchstick Test: Dip a matchstick in decoction of pale catechu, dry in air & dip it in conc. HCl and

warm it near the burner.

Magenta or purple color

Due to formation of phloro-glucinol


PALE CATECHUPALE CATECHU

Adulterants: Mineral matter like clay, ferric hydroxide, etc. Starch and astringent extracts. Gambier from Dutch East Indies.

Uses: Local astringent, in the form of a lozenge. General astringent in diarrhoea. Mainly used in dyeing and tanning industries. Also for protecting the fishing nets.

Sr. No TEST OBSERVATION INFERENCE

4 Vanillin-HCl Test: Treatment of the powdered drug with 1g

vanillin, 10ml alcohol, 10ml conc. HCl

Pink or red color Due to formation of phloro-glucinol


BLACK CATECHU


BLACK CATECHU SYNONYMS: Kattha, Cutch, Khadir-catechu, Catech-nigrum,

Peru catechu. BIOLOGICAL SOURCE: Black catechu is dried aqueous

extract prepared from the heartwood of Acacia catechu and Acacia chundra.

Family: Leguminosae. GEOGRAPHICAL SOURCE: India, Burma. MANUFACTURE OF BLACK CATECHU:1. Traditional Method: Heartwood separated Boiled in earthen vessel, till all the soluble portion is

extracted from it cooled naturally till it is converted to semi-solid mass on cooling, less soluble fraction separates out, which is Kattha semi-solid mass is cutch transferred to rectangular pits, at the bottom of which sand & clay are placed cutch part is absorbed by clay and the solid mass is taken out & moulded into blocks.


BLACK CATECHU2. Modern Method: Red heart-wood obtained by felling the tree separate the bark

& sapwood cut into chips mechanically & put into extractors steam is passed through the drugextract concentrated under vacuum cooled by refrigeration

centrifuged to isolate the cake of kattha cake moulded in desired sizes & dried mother liquor left behind is concentrated, which on cooling gives cutch.

MORPHOLOGICAL CHARACTERS:

Occurrence: Occurs in black or brownish black irregular mass. Outer surface: Rough & dull and rarely glossy; shows covering of

leaves. Fracture: Hard & brittle. Fractured surface: Glassy and porous and sometimes it is soft.


BLACK CATECHU Solubility: Partially soluble in cold water & alcohol; completely soluble in

hot water. Color: Black. Odour: Odourless. Taste: Bitter I beginning and astringent afterwards.

CHEMICAL CONSTITUENTS: 10 to 12% Acacatechin:

It is diastereomer of 5,7,3’, 4’- tetrahydroxy flavan-3-ols. Also called acacia catechin. Acacatechin undergoes oxidation to catechu-tannic acid in presence of

water; and the latter constitutes about 30% of the drug. Acacatechin contains (-) epicatechin which is the trans form of

acacatechin. Catechu red. Quercetin & Quercitrin. Contains no chlorophyll and fluorescent- substance, present in pale

catechu.


BLACK CATECHU


BLACK CATECHU

CHEMICAL TESTS:

1. Vanillin-HCl Test: Because of the presence of catechin, black catechu gives pink or red color with vanillin and HCl.

2. Matchstick Test: Woody side of matchstick is dipped in solution of tannins. It is dried and dipped in conc. HCl and heated over the flame of the burner. Catechin when treated with hydrochloric acid produces phloroglucinol, which burns along with lignin to give purple or magenta color.

3. Aqueous extract of black catechu + Lime water Brown color red ppt, on standing.

4. Dilute solution of black catechu + ferric ammonium sulfate green color add NaOH to this

purple color.


BLACK CATECHU STANDARDS:

Ash value: Not more than 6% w/w Water insoluble residue: Not more than 25% Alcohol insoluble residue: Not more than 90% w/w Loss on drying: Not more than 25%

USES: Kattha:

Astringent externally for boils, skin eruptions and ulcers. Used in cough and diarrhoea. Cooling and digestive properties.

Cutch: Not much used medicinally Other uses: dyeing & coloring, water softening, removal of mercaptans

from gasoline, protective for fishing nets, in manufacture of ion-exchange resin.


REFERENCES1. Dr. S. H. Ansari; Essentials of Pharmacognosy; Birla Publications Pvt.

Ltd.; New Delhi; 4th E dition; 2010; Page- 342, 346.

2. S. B. Kokate, A. P. Purohit, S. B. Gokhale; Pharmacognosy; Nirali Prakashan; Pune; 44th Edition; 2010; Section- 9.13, 9.16.

3. J. S. Qadry; Pharmacognosy; B. S. Shah Prakashan; Ahmedabad; 15th Edition; 2010; Page-299, 300.

Drugs Containing Tannins

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