Page 25 - Practical handout Lev 1-Pharm D- 2024-2025-with spec

Pharm D Level 1 Medicinal plants (PG 101)

Tests for identity
I. Microscopic Examination: to detect the source of starch: maize, potato...etc
II. Iodine test: starch gives blue color with iodine solution.

b- Proteins
-They are complex organic nitrogenous substances.
-They consist of carbon, hydrogen, oxygen and nitrogen.

A Protein molecule is made up of polymer of amino acid molecules linked together by
peptide linkages.

-Proteins are found in the form of solid granules known as aleurone grains

Typical Aleurone Grain
-It is enveloped by a thin protein membrane,
in which are embedded:

a-One or more angular bodies called crystalloids.
b- One or more globular bodies termed globoids.

-The crystalloid occupies the major portion of the granule

, while the globoid occupies the narrower part.
- Alerone grains are stained

1- yellow with picric acid , leaving globoid unstained .
2- Red with Millon's reagent
3- yellow-brown with iodine solution.

c- Fixed Oils and Fats

They are esters of fatty acids and the trihydric alcohol; glycerol,
usually called glycerides, triglycerides or glyceryl esters.
- They are stored in form of fixed oil globules

There are two types:-
1- Liquid fats: as fixed oils
2- Solid fats: as wax, suberin, cutin

They are colored
✓ Brown or black with a 1% solution of osmic acid.

✓ Red with Suddan III and dilute tincture of Alkana.

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