Page 357 - Pharmacognosy 2 PG303 (1)

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Constituents It is a galactan (polysaccharide) formed of 1,3- linked Chiefly of protein glutin.
D-galactose which is partially Sulphated.
• Suspending agent • Nutrient jelly
Uses • Bulk laxative • Base for glycerin suppositories
• As gel in bacteriological
culture media and plant tissue
culture
• For making emulsions

• For thickening ice cream

Tests for identity: Stiff jelly Translucent jelly
1-Cooling of hot
solution
2-Microscopical Boil agar with HCl → set aside No cellular structure
examination 10min→decant→examine the residue
microscopically

3- Tannic acid No precipitate is formed Brown ppt
test
4- Barium chloride test Agar +H2O→ boil + HCl and No ppt
heat for 30 min. on water- bath
+1 mL BaCl2 T.S.→ white ppt
5- Millon’s reagent No ppt Brick-red ppt

6- Ruthenium Particles-stained deep red No color
red test
7- Soda lime test No Ammonia gas evolved Heat gelatin with soda lime
→ Ammonia gas evolved

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