Page 38 - final Practical handout PG 303-Cogno-2- 2024-2025
P. 38
Clinical Pharm D Level 2 Pharmacognosy-2 (PG 303)
Item Subterranean drugs Rhubarb الراوند
Liquorice عرق سوس
Macroscopical
characters
Cylindrical pieces. Rectangular pieces (barrel).
Very sweet taste. Bitter with slight astringent taste.
Gritty under teeth??
Fracture: fibrous in bark, Colors saliva yellow
splintery in wood.
Fracture: granular (not fibrous).
✓ With 1-2 drops of 66%
H₂SO₄, an orange red color is ✓ Micro sublimation: powdered
produced. Rhubarb gives a yellow needle
shaped sublimate which
✓ With water, a voluminous dissolves in KOH give red
froth is produced. color.
✓ With Fehling reagent on W.B ✓ Borntrager’s test: Shake
Chemical tests give a red ppt. due to reducing powder with ether, take ether
layer with aq. NH₄OH gives
sugars. red color.
✓ Alcoholic extract in UV light
gives brown color.
✓ FeCl₃ test (gallotannins) gives
bluish black color.
Rhapontic rhubarb
◼ Rhaponticin which is a stilbene derivative that has estrogenic effect.
◼ It gives blue fluorescence in UV radiation unlike rhubarb gives brown
fluorescence.
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