2. INTRODUCTION
Term Pharmacognosy is combination of two Greek words,
‘Pharmakon’ means A drug and ‘gnosis’ means to acquire
knowledge of
The nomenclature Pharmacognosy first used by German Medical
student in 1815, he wrote his doctoral thesis titled Analectica
Pharmacognostica.
Initially, in 19th century, Pharmacognosy known as Materia medica,
means study of crude drugs obtained from plants, animals and
mineral kingdom.
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3. Definition of Pharmacognosy
Pharmacognosy is defined as “ Scientific and systemic study of
structural, physical, chemical and biological characters of crude
drugs – obtained from natural sources, along with history, method
of cultivation, collection and preparation for market.
Crude drugs :
• Crude drugs are the drugs which are obtained from natural
sources like plants, animals, minerals, marine source or from
microorganisms and they are used as such as they occur in
nature without any processing, except drying and size reduction.
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4. HISTORY OF PHARMACOGNOSY
In the early period, when primitive man went in search of food, he ate
at random plants or their parts like fruits, leaves, tubers, etc.
If no harmful effects were observed, he considered them as edible
plants and used them as food.
If he observed other effects, he considered them as non-edible plants.
According to effect observed, he used them in treating symptoms or
disease conditions.
If any plant caused Diarrhoea, he used as purgative.
If any plant caused poisonous effect or death, he used as arrow poison
for the hunting purpose.
This knowledge was obtained by trial and error and results were passed
on from one generation to the other, and new knowledge was added in
the same way.
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5. Scientists and their work in the development of Pharmacognosy
Name Profession Work done Time period
Hippocrates
Father of Medicine
Greek
scientist
Studied Human Anatomy
and Physiology
460-360 B.C.
Aristotle
Father of Biology
Greek
philosopher
Animal kingdom 384-322 B.C.
Theophrastus Greek
philosopher
Plant kingdom 370-287 B.C.
Carl Linnaeus
Father of
Taxonomy
Swedish
botanist
Bionomical classification 1753
Pedanius
Dioscorides
Greek
physician
De materia medica book 78 A.D.
Galen Greek
pharmacist
Galenical pharmacy
Extraction of chemical
constituents from plants
Pain relieving material
131-200 A.D.
C. A. Saydler German
Scientist
Coined word
Pharmacognosy
1815
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6. Indian history of Pharmacognosy
In India, knowledge of medicinal plants is very old, and medicinal
properties of plants are described in Rigveda and in Atharvaveda,
from which Ayurveda has developed.
Ayurveda is the term for traditional medicine of ancient India and it is
believed to be prevalent for last 5000 years.
Ayur means life and veda means the knowledge or science, so
Ayurveda means science of life.
The Ayurvedic writings can be divided into two main treatises are
Charaka Samhita and Sushruta Samhita.
A large portion of the Indian population even today depends on the
Indian System of Medicine.
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8. The development was mainly due to the following four events :
• Isolation of Penicillin in 1928 by William Fleming
• Large scale production in 1941 by Florey and Chain
Penicillin
• Isolation of Reserpine from Rauwolfia roots and confirming its
Hypotensive properties
Reserpine
• Isolation of Vinca Alkaloids, especially Vincristine and
Vinblastine, having anticancer properties.
• Vincristine is useful in Leukaemia.
Vincristine
Vinblastine
• Steroid hormone like progesterone were isolated by partial
synthesis from Diosgenin and other Steroidal saponins by
Marker’s method
• Cortisone and Hydrocortisone are obtained from Progesterone
by Chemical and Microbial notes.
Steroid hormones
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9. Important aspects of natural products that led to modern developments :
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1. Isolation of Phytochemicals :
• Strong acting substances such as glycosides of digitalis, alkaloids from
Vinca, Rauwolfia, Ergot and Opium alkaloids were isolated and their
Pharmacological activities were studied.
• Caffeine from tea leaves, coffee beans
• Vanillin from Vanilla beans
10. 2. Structure Activity Relationship
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The structure–activity relationship (SAR) is the relationship between
the chemical structure of a molecule and its biological activity.
Tubocurarine and Toxiferine from Curare, having muscle relexant
properties because of Quaternary ammonium groups.
Hypotensive activity of Reserpine is because of Trimethoxy benzoic
acid moiety.
Presence of Lactone ring is essential for the activity of Cardiac
glycosides.
Reserpine
Tubocurarine Digoxigenin
11. 3. Drugs obtained by partial synthesis of natural products :
The process in which compounds isolated from natural sources are
used as starting materials to produce other organic molecules is called
as partial synthesis.
Example : Oxytocic activity of methyl ergometrine is more than that
of ergometrine.
4. biosynthetic pathway :
Biosynthesis is a multi-step, enzyme-catalyzed process where
substrates are converted into more complex products in living
organisms. In biosynthesis, simple compounds are modified, converted
into other compounds, or joined together to form macromolecules.
Some of the important pathways are Calvin’s cycle, Shikimic acid
pathway for aromatic compounds.
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12. 5. Technical products :
Natural products besides being used as drugs and therapeutic aids, are
used in number of other industries such as food, beverages, spices,
etc.
Example : coffee beans and tea leaves besides being the source of
caffeine are used as popular beverages.
Mustard seeds and Clove are popular spices.
Cinnamon oil and Peppermint oil besides being used as carminative,
are used as flavouring agents.
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13. 6. Pharmaceutical aids :
Pharmaceutical aids are the drugs or other than drugs which have
no or little pharmacological effects but they are essentially used in
the preparation of pharmaceutical dosage form like tablets,
Injections, emulsions, ointments, etc.
Volatile oils are used as flavouring agents.
Gelatin is used in coating of pills and preparation of capsule shell.
Carbohydrate containing drugs like glucose, sucrose and honey are
used as sweetening agents.
Fixed oils and waxes from natural source are used as base in
preparation of various pharmaceutical formulation like, creams and
ointments.
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14. SCOPE OF PHARMACOGNOSY
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Herbal
medicines
Food
supplements
Tissue culture
Research and
development
New drug
discovery and
development
15. pharmacognosy has enabled vegetative drugs under botany and
animal drug under zoology, through taxonomy.
WHO has estimated that 80 % of world population depends on
herbal medicines for their primary health care.
Some of the very famous drugs are Senna, Aloe, Rauwolfia,
Turmeric, Tulsi, etc.
Pharmacognosy is vital link between pharmacology and
medicinal chemistry, because it enables isolation of purified
natural drugs, converts into medicine and evaluate its
therapeutic effects.
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16. Due to rapid growth in demand and popularity of natural
products, research has been directed towards patentable drug
discovery and development in the field of Pharmacognosy.
More than 45,000 plant species found in the ecosystem of our
country, and only a small percentage of plants has been
phytopharmacologically investigated.
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17. Pharmacognosy links Ayurvedic and Allopathic systems of
medicines to each other.
Cadila Pharmaceuticals, in collaboration with the Indian
Institute of Integrative medicine (IIIM), has developed a fixed
dose combination product containing –
Rifampicin 200 mg
Isoniazid 300 mg
Piperine 10 mg
For treatment of tuberculosis
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18. Academics : teaching in colleges, universities, museums and
botanical garden.
Pharmaceutical industry : research and development area
Government : placement in government agencies like medicinal
plant research, AYUSH projects, food and drug administration,
etc.
Modernization of conventional or traditional dosage form is
opening doors to Industrial Pharmacognosy.
Artemisin is a new anti-malarial drug obtained from Artemisia.
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19. Pharmacognostical scheme
To describe drugs in a systematic manner is known as
pharmacognostical scheme, which contains following headings.
1. Biological source:
This includes the biological names of plants or animals of the drug and
its belonging family.
Botanical name includes genus and species.
Biological source also includes the family and part of plant used as
drug.
Some abbreviations are written after the botanical names, which is
biologist responsible for the classification.
Example : Aloe consists of whole leaves or juice collected by incision
made on base of leaves of Aloe vera Linn, belonging to the family
Liliaceae.
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20. 2. Geographical source :
It includes the areas, in which plant in cultivated.
3. Cultivation, Collection and Preparation :
This includes the method, specific requirements and time of cultivation
and collection.
Storage condition and method of preparation for the market.
4. Morphological characters :
This includes morphological characteristics of plant parts like length,
thickness, colour, odour, taste, shape, etc.
In case of powdered drug colour, odour, taste and texture is included.
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21. 5. Microscopical characters :
This is one of the important aspects of pharmacognosy, as it helps to
identify drug.
Under this section, all the detailed microscopical characters of a drug is
described.
6. Chemical constituents :
It includes the chemical constituents present in the drug.
7. Uses :
It includes traditional use and pharmacological activity of a drug or the
disease in which the drug is effective.
8. Substituents :
The drug which is used during non-availability of original drug is known
as substituent.
It has same type of physiological active constituents, however the quality
of drug may be different.
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22. 9. Adulterants :
Adulteration is defined as substituting original crude drug partially or
wholly with other similar looking substances.
The substance, which is mixed, is free from therapeutic property.
With the knowledge of the diagnostic characters of drugs, the
adulterants can be detected.
Example : mixing a buffalo milk with goat milk is substitution.
But mixing water in the milk is adulteration.
In first case goat milk is substitute and in second case water is
adulterant.
10. Chemical tests :
Knowledge of chemical test becomes more important when
morphology of drug is not well defined.
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23. 11. marketed formulations :
If any preparation or formulations are present in the market, then it is
included in this section.
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