1. Introduction
to
Pharmacognosy and phytochemistry-i
B.Pharm, 4th semester

2. Brief idea about the subject
• Pharmacognosy is the study of drugs derived from natural sources.
• It forms an important part of pharmaceutical research and development.
• Pharmacognosy involves the identification, physicochemical
characterization, cultivation, extraction, preparation, quality control, and
biological assessment of drugs.
• A plant leaf, flower, root, animal or plant extract may be used to isolate the
bioactive chemical.
• The term "Pharmacognosy" was coined by Anotheus Seydler in 1815, a
German botanist, from the two Greek words "pharmakon", meaning drug
or medicine, and "gnosis", meaning knowledge.
• According to the American Society of Pharmacognosy, the definition of
pharmacognosy is "the study of the physical, chemical, biochemical, and
biological properties of drugs, drug substances or potential drugs or drug
substances of natural origin as well as the search for new drugs from
natural sources".
• Crude drugs: Simple drugs exist in natural forms, obtained from plants,
animals, marine and minerals in the raw forms used to treat certain
diseases.
• Undergone no treatment other than collection and drying.

3. Pharmacognosy fields
• Ethnobotany/Ethnomedicine: The study of the
traditional use of plants for medicinal purposes;
• Ethnopharmacology: The study of the pharmacological
qualities of traditional medicinal substances;
• Phytotherapy: Medicinal use of plant extracts.
• Phytochemistry: Study of chemicals derived from plants
(including the identification and study of structure
analogue of new drug candidates derived from plants
sources).
• Zoopharmacognosy: The process by which animals self-
medicate, by selecting and using plants, soils and insects
to treat and prevent disease.
• Marine pharmacognosy: The study of chemicals
derived from marine organisms.

4. Importance of pharmacognosy
• Primary source of medicines (from ancient time to present day), for
example–Digitoxin, Reserpine, Morphine, Ergotamine, etc.
• Identification of crude drugs, its biological source, part used, family,
its collection and cultivation, preparation, adulteration, storage
condition, medicinal uses.
• Isolation, analysis, chromatographic studies and characterization of
phytoconstituents OR bioactive molecules
• Standardization (physical, chemical and biological (pharmacological
evaluation) of crude drugs and herbal formulations
• Act as linking bridge between Pharmacology, pharmachemistry and
pharmaceutics.
• Base or platform for drug development and research
• Documentation/preservation of crude drugs
• Study of biosynthetic pathways
• Production of secondary metabolites by PTC

5. Limitations
• A natural compound may be highly active but
usually this is associated with high toxicity problem.
• Some compounds are found in natures that give
beneficial pharmacological actions but their
potencies are too low to be employed therapeutically.
• The yield of active natural products may be very low
and thus the production cost of those drugs will be
very high.
• The source of a natural drug may be very limited
with respect to geography, season and climate, etc.

6. History of Pharmacognosy
• The Babylonians were aware of the Medicinal effects of a
number of plants.
• Ancient Egyptians possessed a sound knowledge of human
anatomy as well as a knowledge of the medicinal uses of
many plants and animals.
• Papyrys Ebers- written in 1550 B.C. (16th century) &
discovered in a tomb of a mummy contain more than 800
formula & 700 different drug.
• In India, the study of the drugs was started about 5000 years
ago at the time of the Vedas. Ayrurvedic system (1200 B.C.
Ago list with 127 plants.) Charaka-physician, 50 groups of 10
herbs each for illness.(Charak Samhita); Sushruta-surgeon, 7
groups of 760 herbs based on properties of plants. (Sushruta
Samhita)
• Hippocrates (460 - 370 B.C.) deals with anatomy and
physiology in many of his treatises.“Father of Medicine”.

7. Egyptians (Ebers papyrus, 1550 BC)

8. Authors of antiquity
Hippocrates (460-377 BC)
“The Father of Medicine”

9. Dioscorides (40-80 AD)
“De Materia Medica” (600 medicinal
plants)

10. • Aristotle (384 - 322 B.C.), the great
philosopher wrote much about the animal
kingdom and his writings were placed on
scientific footing free from all superstitions.
• Theophrastus (370-287 B.C.) wrote about
plants and described medicinal uses of
plants.
• Dioscorides a Greek physician of the 1st
Century A.D. was the writer of the first
Materia Medica (40- 80 A.D.) Here he
described 600 medicinal plants, including
Belladona, Colchicum, Opium, Hyoscyamus,
etc.
• C.A. Seydler, German scientist, a medical
student at Halle, Germany in 1815; wrote his
doctoral thesis titled Analectica
Pharmacognostica.
• Carolus Linnaeus (1707 – 1778) classified
the plant & introduced the system of naming
the plant known as binomial system.

11. • Galen (131 -200 A.D.) the
first Pharmacist, who
described the method of
preparing drugs of vegetable
and animal origin and laid
down many formulas
contained in a treatise(thesis)
of 20 volumes.
• Plant Classification was
developed by Benthan &
Hooker (1862 – 1863), A.W.
Eichler (1883), Engler &
Prandtl (1887 – 1898)
• In 1865, G. Mendel’s
important observation on plant
hybrids

12. Scope of Pharmacognosy
• 1. ISOLATION OF PHYTOCHEMICALS
• Glycosides from digitalis leaves,
• Alkaloids from the plants of Belladonna, Hyocyamus, Rauwlofia
• Morphine and other alkaloids from the plant opium
• 2. STRUCTURE ACTIVITY RELATIONSHIP
• 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
• Preparation of Steroid hormones from diosgenin by acetolysis and
• oxidation and further preparation of cortisone by microbial
reactions.

13. • 4. NATURAL PRODUCTS AS MODELS FOR
SYNTHESIS OF NEW DRUGS
• Morphine is the model of a large group of potent drugs
• Cocaine for local anaesthetics
• Atropine for certain spasmolytics
• 5. DRUGS OF DIRECT THERAPEUTIC USES
• Antibiotics, steroids, ergot alkaloids, vincristine, etc
• 6. BIOSYNTHETIC PATHWAYS INVESTIGATION
• Biosynthetic pathways of primary and secondary
metabolites.
• 7.CULTIVATION AND COLLECTION OF
MEDICINAL PLANTS
• Clove, cinchona , cinnamon, senna, opium, etc.
• 8. PREPARATION OF HERBAL FORMULATIONS
• Churnas, asvas, aristas, leha, etc.

14. Development of Pharmacognosy
• Modern Pharmacognosy occurred during
1934 - 1960.
• This development was mainly due to some
events like:
Discovery of Penicillin in 1928
Isolation of Resperine 1952
Anticancer properties of Vinca rosea
Discovery of Dioscorea was utilized to
prepare semisynthetic steroidal hormones.

15. Development of Pharmacognosy
• Pharmacognosy as an applied science.
• It played a crucial role in the development
of different disciplines of science.
• Pharmacognosy is an imp link between
Pharmacology and Medicinal Chemistry
• Step by step processes in biosynthesis of
Primary & Secondary metabolites were
presented before the world.
• Invention of microscopy and different
chemical test reagents.

16. Development of Pharmacognosy
•Knowledge of
• Plant taxonomy
• Plant breeding
• Plant pathology
• Plant genetics
• Are helpful in the development of cultivation
technology for medicinal and aromatic plants.