Page 127 - Pharmacognosy 2 PG303

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

Powder

It is light greenish- yellow with narcotic odor and bitter acrid taste. It is characterized
microscopically by the following:
1- Fragments of the leaf show sinuous epidermal cells, striated cuticle and anisocytic stomata.
2- Numerous branched and non- branched glandular trichomes and few uniseriate, multicellular

non- glandular trichomes.
3- Fragment of the lamina in sectional view shows the isobilateral structure of the leaf.
4- Fragments of spiral and pitted vessels and wood fibers.
5- Numerous prism and twin crystals of calcium oxalate and rarely clusters or microsphenoids.
6- Few spheroidal pollen grains with finely pitted exine.
7- Lignified sclereids of the seed coat and the apical region of the pericarp.

Constituents

Alkaloids are mostly hyoscyamine and contain hyoscine and apoatropine.

Uses

Hyoscyamine:
- Antispasmodic and supresion of secretions.
- Antidote in poisoning by physostigmine or organic phosphoric acid insecticides.

Hyoscine (scopolamine):
- C.N.S. depressant (sedative) used in prophylactic against motion sickness.
- In combination with morphine in pre-medication before operations.

Chemical test

Vitali's test for solanaceous alkaloids:
The powder (1 g) + 10 mL dil HCl, boil for 2 min, filter, evaporate to dryness + HNO3 (10 drops)
evaporate → residue (polynitrobenzene derivatives) + alc. KOH (2 drops) → violet color.

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