Tragacanth : Source, Production, Chemical Constituents, Chemical Tests, Uses and Adulterants

Source, Method of Production, Chemical Constituents, Chemical Tests, Uses and Adulterants of Tragacanth


At the end of this lecture, student will be able to:

• Discuss the pharmacognostical aspects of

- Tragacanth


Tragacanth Plant image

Synonym: Tragacantha, gum tragacanth

Source: Dried gummy exudation obtained by incising the stems and branches of Astragalus gummifer and other species of Astragalus

Family: Leguminosae

Geographical distribution: Iran, Greece, Turkey, Iraq, Syria and India

Tragacanth - Method of preparation/collection

• Stems and branches incised, gum exudes and dried

• Form of incision: Vertical slits- ribbon shaped pieces, punctures-tears

• Transformation of the cell walls of the pith and medullary rays

• First tapping - white, subsequent tapping - yellow coloured gum


• White or pale yellowish or brown

• Odorless

• Mucilagenous

• Thin, flattened ribbon or powder

Chemical constituents

• Tragacanthin

• Bassorin- Viscosity – 60% - (minimum 3.75 % of methoxy groups)

      - Tragacanthic acid - galacturonic acid, galactose, xylose and fucose

      - Neutral polysaccharide on hydrolysis yields arabinose and galactose

      - Glycoside of sterol derivative

Chemical tests

• Sample + water: Insoluble

• Fehlings test: Red precipitate

• Sample + ruthenium red: NO pink mucilage

• With N/50 Iodine solution: Green colour

• With alcoholic potassium hydroxide solution: Canary yellow colour

• With lead acetate solution: White precipitate

• With lead sub acetate solution: White precipitate


• Suspending, emulsifying agent

• Binding agents in tablets

• Demulcent

• Emollient in cosmetics

• Thickening agent


• Indian tragacanth (sterculia gum) - Sterculia urens (sterculiaceae)

• Katira gum - Cochlospermum gossipium (Cochlospermaceae)

• Vermicelli tragacanth / hog gum - Astragalus cylleneus


• Tragacanth is from Astragalus gummifer with tragacanthin and bassorin content

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