Pharmacognosy - 1

Front 1

Define Pharmacognosy.

Back 1

Branch of bioscience, which treats in detail,
medicinal and related products of crude or primary type, obtained from natural sources
such as plants, animals and minerals

Front 2

What are crude drugs?

Back 2

Drugs obtained from natural sources -- in their unprocessed forms.

Front 3

Etiology of Pharmacognosy.

Back 3

Pharmacognosy = Pharmakon + Gignosco
– Pharmakon „a drug‟
– gignosco „to acquire knowledge of‟

Front 4

Era of Pure compounds?

Back 4

1803 - Pure phytoconstituents were
isolated from the plant extracts using various separation and isolation techniques.

• Morphine from opium poppy (Papaver somniferum, Papaveraceae), which was first identified by FW Serturner of Germany ) in 1804 and chemically characterized in 1817 as
an alkaloid. The full structure was established in 1923, by JM Gulland and R Robinson, inManchester.

• Strychnine (1817) - from Strychnos spp.(Loganiaceae), was used as a tonic and stimulant

• Quinine - from cinchona bark (Cinchona succirubra and others), was first isolated by Pierre Joseph Pelletier and Joseph Bienaime Caventou of France in 1820; the structure was elucidated in
the 1880s by various laboratories.

• Caffeine (1821) - from the coffee shrub (Coffea arabica and C. canephora, Rubiaceae); its structure was
elucidated in 1882. Stimulant.

• Nicotine (1828) - Nicotiana tabacum. CNS Stimulant.

• Atropine (1833) - from belladonna (Atropa belladonna, Solanaceae), was used at the time for asthma.

• Cocaine (1855)

• Salicin, from willow bark (Salix spp., Salicaceae), was first isolated by Johannes Buchner in Germany

Front 5

Sources of Information?

Back 5

• Early Arabic and European records.
• Classical Arabic, Greek and Roman records.
• Classical Chinese records.
• Other Asian traditional medicine.
• The European Middle Ages and Arabia.
• Printed reports in European tradition.

Front 6

Discoveries in Pharmacognostic research in 19th and 20th centuries.

Back 6

• In the 19 th century, the chemical structures of many of the isolated compounds
were determined.
• In the 20 th century, the discovery of important drugs from the animal kingdom,
particularly hormones and vitamins.
• Microorganisms also became a very important source of drugs.

Front 7

Cognosy is multidisciplinary. Explain.

Back 7

1. Botany & Zoology which includes history [biological name, family],
distribution, cultivation, collection, study of morphological & microscopic characteristics,
processing of the crude drug and its traditional uses.
2. Pharmacology.
3. Phytochemistry.

PHARMACOGNOSTIC STUDY IS RELATED TO:
– Botany
– Ethnobotany
– Marine biology
– Microbiology
– Chemistry (phytochemistry)
– Pharmacology
– Pharmaceutics

Front 8

Value of natural products..?

Back 8

Compounds from natural sources play three significant roles in modern
medicine:

1. They provide a number of extremely useful drugs that are difficult, if not
impossible, to produce commercially by synthetic means [eg. Taxus brevifolia]
Taxol.
2. Natural sources also supply basic compounds that may be modified slightly to
render them more effective or less toxic [semi-synthetic drugs]. [eg. Artemisia
annua-Artemisinin (lactone group)-Artemether (acetal group)].
3. Their utility as prototypes or models for synthetic drugs possessing physiologic
activities similar to the originals. [Example - Camphor].

Front 9

Applications of Pharmacognosy.

Back 9

APPLICATIONS OF PHARMACOGNOSTICAL SKILLS
1. Analysis of other commodities:
• Foods, spices, gums, perfumes, fabrics & cosmetics.

2. Used by:
• Forensic sciences & quality-control scientists.

3. Role in pure sciences:
• Botany, plant taxonomy & phytochemistry.

4. Botanists and chemists working on:
• plant taxonomy & genetic/enzymatic studies.
• Plant tissue culture.
• Effects of chemicals on plant metabolites.

5. Bioassay-guided fractionation and isolation techniques.
-> Meaning step-by-step separation of extracted components based on differences in their physicochemical properties, and assessing the biological activity, followed by next round of separation and assaying.

Front 10

Types of Drugs derived from natural source

Back 10

TYPES OF DRUGS DERIVED FROM PLANTS
1. Herbal drugs, derived from specific parts of a medicinal plant
Eg.

2. Pure Isolated compounds
Eg.

3. Nutraceuticals or “functional foods”
Eg. Garlic, ginger, turmeric and many other herbs
and spices
l anthocyanin-orflavonoid-containingplantssuch
as bilberries, cocoa and red wine
l carotenoid-containing plants such as tomatoes,
carrots and many other vegetables.

Front 11

Scope of Cognosy

Back 11

# The pharmacognosist would serve in various aspects as follows:

->Academics: Teaching in colleges, universities, museums
and botanical gardens.

->Private industry: Pharmaceutical companies, consumer
products testing laboratories and private commercial testing
laboratories, the herbal product industries, the cosmetic
and perfume industries, etc.

->Government: Placement in federal agencies, such as the
Drug Enforcement Agency, the Food and Drug Admin-
istration, the U.S. Department of Agriculture, Medicinal
plant research laboratories, state agencies like forensic
laboratories, environmental laboratories, etc.



#Undoubtedly, the plant kingdom still holds large number
of species with medicinal value which have yet to be discov-
ered. Lots of plants were screened for their pharmacological
values like, hypoglycaemic, hepatoprotective, hypotensive,
antiinflammatory, antifertility, etc. pharmacognosists with
a multidisciplinary background are able to make valuable
contributions in the field of phytomedicines.