Scope and present status of Pharmacognosy

Pharmacognosy: The Pharmacognosy is broadly defined as the scientific and systematic study of the structural, physical, chemical and sensory characters of crude drugs of vegetable, animal and mineral origin along with their history, method of cultivation, collection and preparation for the market.

Scope of Pharmacognosy: Pharmacognosy has broad scope in the field of pharmacy such as:

1. Isolation of phytochemical: Eg; Strong acting substances such as glycosides from digitalis leaves, Alkaloids from the plants of Belladonna, Hyocyamus, Rauwlofia Morphine and other alkaloids from the plant opium were isolated and clinical uses studied.

2. Structure Activity Relationship: Eg: Tubocurarine and Toxiferine from curare plant have muscle relaxant properties because of quaternary ammonium groups.

The hypotensive and tranquillizing actions of reserpine are due to the trimethoxy benzoic acid.

3. Drugs obtained by Partial Synthesis of Natural Products: Eg : Preparation of Steroid hormones from diosgenin by acetolysis and oxidation and further preparation of cortisone by microbial reactions .

4. Natural products as models for synthesis of New drugs: Eg: Morphine is the model of a large group of potent drugs, Cocaine for local anaesthetics, Atropine for certain spasmolytics.

5. Drugs of direct therapeutics uses: Among the natural constituents which even now cannot be replaced are important group of antibiotics, steroids, ergot alkaloids, vincristine etc.

6. Biosynthetic pathways investigation: Biosynthetic pathways are of primary and secondary metabolites. Some of the important pathways are Clavin‘s cycle of photosynthesis, Shikimic acid pathway of aromatic compounds. Acetate hypothesis for antharacene glycosides. Isoprenoid hypothesis for terpens.

7.Cultivation and collection of medicinal plants: Eg. Clove, cinchona, cinnamon, senna, opium, etc.

8. Preparation of herbal formulations: Eg. Churnas, asvas, aristas, leha, etc

9. Development of Tissue cultured plants: Eg. Citrus species, Solanacea plants etc.

A vital contribution to the advancement of natural science:

• This has done by the advanced technologies of cultivation, purification, identification (characterization) of pharmaceuticals from nature.

• Concepts of biochemistry and chemical engineering help in the improvement of collection, processing and storage technologies of pharmaceuticals.

• It also gives knowledge of chemotaxonomy, biogenic pathways for the formation of acute ingredients.

A vital link between pharmacology and medicinal chemistry:

• Newly detected plant drugs are converting into medicine as purified phytochemicals.

• Pharmacognosy is essential for the evolution of new medicines because crude drugs are used for the preparation of galanicals or as a sources of therapeutically active metabolites.