2. Pharmacognosy deals with:
• The plants and animals that yield drug
substances.
• 2-The chemical, physical and biological properties
of the substances.
• 3- The methods employed in harvesting the crude
drugs.
• 4- The methods employed in processing and
storing crude drugs.
• 5- The methods used for extraction and
preparation of their active constituents.
• 6- The knowledge of the medicinal uses of the
crude drugs.
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3. For detailed description of drugs, the following
parameters should be fulfilled:
• the biological and geographical sources,
• a short note on the history
• and the name of the drug.
• cultivation of the plant,
• collection of the part used,
• drying,
• packing
• and other treatments of the drugs during its
course from the biological source to market.
1- Origin:
2- Cultivation and preparation:
4. • Including the macro- and microscopical
characters.
•
• The chemical identification of the drug.
3- Characters:
4- Constituents
5- Chemical tests
6- Adulteration and/or substitution
7- Isolation and purification of the active constituents
8- Uses of the drug in folk medicine and therapy
5. Crude drug = Raw Drug
• It is the harvested and usually the dried plant
or animal sources of pharmaceutically or
medicinally useful products before they have
undergone extensive processing or
modification.
• It is a part of plant or animal, which has been,
or still, used in medicine or such products of
these vegetable parts which have been
extracted but not used by it.
Crude Drugs
6. • Entire plants or animals i.e Lobelia, Mentha,
Cantharidis, Cochineal.
• Entire members of plants or animals i.e Clove
and thyroid gland.
• Minerals i.e. Chalk, Kaolin and Talc.
• Substances derived from plants or animals i.e.
Opium, Aloes, Tragacanth, Resins, Musk, Beeswax
and Gelatin.
Examples of Crude Drugs:
7. • Fibres and Fabrics used for making surgical
dressings
• i.e Materials used as strainers for filteration or
for clarifying cloudy liquids, “Filteration
Material” e.g. Diatomite and Asbestos, also
substances as Agar, Gelatin and Wax.
• Materials used for destruction of insect pests
“Insecticides and Pesticides” i.e Derris and
Pyrethrum.
8. • 1- Identification of the source of the materials
forming a drug.
• 2- Determination of its morphological characters.
• 3- Investigation of the potency of the drug, purity
and freedom from admixture.
• 4- Planning the proper methods of cultivation of
the medicinal plants yielding these drugs.
• 5- Prescription of details of processes of collection
and preparation.
• 6- Detailed knowledge of the constituents of drugs
and investigation of their chemical nature and
various reactions.
Functions of a pharmacognosist
9. Classification of Crude drugs
Vegetable drugs are usually arranged for study in
one or other of the following ways:
1- Alphabetical:
using either Latin or English names; the drugs are
arranged in an alphabetical order.
2- Taxonomic:
using one of the accepted systems of botanical
classification; the drugs are according to the plants
from which they are obtained in phyla, orders,
families. Genera and species.
10. • 3- Morphological:
• dividing the drugs into groups e.g. leaves,
flowers, fruits, seeds,..... which are referred to
as “Organized drugs", and groups as dried
lattices, extracts, gums, resins, oils, fats and
waxes which are known as “Unorganized
drugs".
• 4- Chemical:
• the drugs are divided into groups according to
their most important constituents.
• e.g. drugs containing volatile oils, glycosides,
alkaloids, bitter principles, tannins,
saponins,......
11. 5- Pharmacological and therapeutic effects:
• grouping of drugs according to the
pharmacological action of their most important
constituents or their therapeutic use.
• e.g. astringent, irritant, drugs affecting the
gastrointestinal tract, drugs promoting systemic
effects on the muscle and nervous system, drugs
affecting the circulatory system, drugs used
chemotherapeutically for the treatment of
infectious diseases, etc....
12. • Drugs are either official or unofficial.
• An official drug is one which is listed and
described in a book recognized by the
government as the legal authority for
standards “Pharmacopoeia’’.
• The 1st Egyptian Pharmacopeia appeared in
English in 1953 and in Arabic in 1961.
Official and unofficial drugs
13. • There are two origins for each drug; the
natural or biological, as well as, the
geographical origin.
• The commercial origin is also of interest
in case of certain drugs.
Origin of drugs
14. • It is the plant or animal yielding it, if a plant,
botanical origin or botanical source and if an
animal, zoological origin or source.
• The knowledge of the biological source
enables one to indicate with certainty the
proper right material and the precise article
one wishes to obtain.
1-The natural or biological
origin (source(
15. • e.g. Strophanthus is used as a heart tonic and
includes about 30 species, all species from the
same district in central Africa.
• One year, the drug is active, even poisonous and
in other cases it is inactive. This is due to the fact
that the drug is gathered from any species, which
collectors amy find.
• If the drug is obtained from one and the same
species the supply of the drug will be always of
the same potency.
• So the identification of the exact origin of the
drug needs comparison with authentic or
genuine samples or identification by comparison
with herbarium or referring to gardens or
museums.
16. The binomial system for nomenclature of
drugs
• Is due to Swedish biologist Linnaus, in this system the
first name, which is always spelt with Capital letter,
denotes the genus.
• whilst the second name denotes the species. It is
however, still equally correct to use capital where the
species is named after a person.
• Thus the species of Cinchona named after Charles Ledger,
who brought its seed from Brazil 1865, is known as
Cinchona Ledgeriana.
• It is noted that the pharmacopoeias and research papers,
botanical names are followed by names of persons which
refer to the botanist who first described the species or
variety.
17. • The specific name is usually chosen to indicate:
1- Some striking characteristics of the plant:
• a- Glycyrrhiza glabra
(glabrous = smooth).
Refers to the fruit of this species which is a smooth pod.
• b- Atropa belladonna
(bella = beautiful, donna = lady)
the juice of the berry placed in the eyes causes
dilatation of the pupils, thus giving a striking
appearance).
• c- Hyoscyamus muticus
(muticus = short).
The plant being short.
18. 2- A characteristic colour:
a- Piper nigrum (nigrum = black)
b- Veratrum viride (viride = green)
c- Citrus aurantium (aurantium = golden yellow)
d- Digitalis purpurea (purpurea = purple)
e- Digitalis lutea (lutea = yellow)
3- An aromatic plant or certain aroma:
a- Myritaceae fragrans (having a fragrant, nice
aroma)
b- Caryophyllus aromaticus (refers to the aroma)
19. 4- Geographical source or history of a drug:
• Cannabis indica (growing in India)
5- Pharmaceutical activity or an active
constituents:
a- Papaver somniferum (sleep inducing)
b- Quillaia saponaria (containing saponins)
6- General meaning or a special indication
a- Allium sativum (= cultivated)
b- Triticum vulgaire (= wild)
20. • It is the region in which the plant or animal
yielding the drug grows.
• Knowledge of the geographical source also
assists in identification of the biological origin,
because it is generally known that plants of
certain type come from particular districts and
one may often exclude from consideration
entire families of plants, as well as, individual
species or one may deduce the possibility that
the drug may be derived from a plant
belonging to one of some few families
characteristic of the region.
2- Geographical sources of drugs
21. • Every climatic region of the earth is the native
habitat of some species of animals and plants.
• Drugs are collected in all parts of the world, the
Mediterranean region yields more drugs than any
region of the world however India, East Indies,
Europe, South and Central America yield
numerous valuable drugs.
• It is important to note that the habitat affects not
only the constituents but also the medicinal value
of the natural drug.
22. • The commercial origin drugs refer to the
countries included in their production and/or
their channels of trade so such drugs frequently
bear a geographical name indicating:
• 1- The country in which they are collected
i.e. English Hyoscyamus
• 2- The city from which they are shipped
i.e Alexandrian Senna
• 3- Indicate a certain veriety
i.e Spanish Liquorice
3- Commercial origin
23. • Production of crude drugs from their
medicinal plants involves the following steps:
• I. Cultivation
• II. Collection
• III. Drying
• IV. Packing
• V. Preservation and protection
Production of Crude Drugs
24. • Crude medicinal drugs may be collected from:
- Wild growing medicinal plants
- Cultivated medicinal plants.
• Plants growing in their native countries are said
to be indigenous to these regions,
• e.g. Aconitum napellus of the mountainous
regions of Europe,
• Hyoscyamus muticus of Egypt, Cannabis sativa of
India.
• Plants are said to be naturalized when they grow
in a foreign land or in locality other than their
native home.
Cultivation of medicinal plants
25. Collection of Crude drugs from wild
growing medicinal plants has the
following disadvantages
• 1- Wild medicinal plants found spread in wide
distribution “unlimited areas”.
• 2- There is significant difficulty in collection and
transportation because they are mostly growing
in deserts and forests far from any means of
transport.
• 3- Continuous extensive collection of wild
medicinal plants can lead to extinction or serious
deficiency of the plant.
• 4- the collected amount of wild medicinal plants
may be insufficient for the market needs.
26. • Adulteration; collection of crude medicinal
drugs from wild sources may lead to
adulteration that can be attributed to
ignorance of collectors who may collect:
• a- The desired plant with others.
• b- Undesirable organ of the desired plant.
• c- The desired plant at improper time.
27. Collection of Crude drugs from
cultivated growing medicinal plants
has the following advantages
• 1- Concentration of a large quantity of the
plant of choice in relatively small areas
simplifies collection.
• 2- Cultivation provides an excellent mean for
control of the purity of the crude drug.
• 3- Cultivation assures regular and constant
supply can be sufficient to market needs.
28. • 4- Cultivation allows producers to apply different
methods for improvement of the gained crude drug by
controlling certain factors:
• a- Treatment of seeds before sowing to ensure
germination and exclusion of defective seeds i.e.
soaking Hyoscyamus seeds in dilute sulphuric acid
fasten germination.
• b- The use of fertilizers which can provide cultivated
plants with certain essential elements as N, K and P
which can increase the produced active constituents.
• c- The use of certain insecticides and pesticides help
control of insect’s infestations.
29. The disadvantages of collection of crude
drugs from cultivated medicinal plants
are:
• 1- The high cost of production when applied
on small scale while economic only when
carried on large scale.
• 2- Some medicinal plants require particular
habitat for their growth and the procedures
of their cultivation usually gain failure.
• i.e. Cannabis requires tropical climate
production of narcotic resin while Aloes
require a heavy rainfall.
30. • For successive cultivation of medicinal plants
and production of crude drugs with quality, it
is necessary to study the conditions under
which medicinal plants flourish in their wild
state and trying to reproduce these conditions
or improve them
31. Factors affecting plant growth and
production of crude drugs
• Classified into:
1- Environmental factors:
• Including water, light, temperature, altitude, etc.
2- Soil and soil contents:
• Including plant nutrients, macro-elements and
micro-elements, active elements, inactive
elements, organic matter and living organisms.
• 3- Growth Regulators.
• 4- Genetics and plant tissue culture.
32. 1- Environmental Factors:
• a- Water:
• Importance of water:
• 1- It is an important component of the cell
which is the building unit for every living
creature.
• 2- It is a vital factor in all biological reactions
and transformations in living beings, it can act
as medium, catalyst, part of the biological
reaction or even end product of it.
33. • b- Temperature:
• Temperature divides the world into various zones and
plant growth is greatly affected by temperature.
• The effect of temperature on the reaction of the plant
which is finally expressed in its effect on the plant
growth as a whole.
• It has a great effect on on seeding
i.e as temperature is increased, the rate of growth is
increases until an optimum value is reached, above
which further increase in temperature leads to a
decrease in growth rate.
• This is due to the fact that chemical reactions, in
general, increase in rate as temperature is increased,
but as it is still further increased, other reactions, such
as heat denaturation and protein inactivation
predominates.
34. • For each plant, growth is designated by three
temperatures:
- The minimum temperature
- The optimum temperature
- The maximum temperature
c- Altitude:
• It affects the growth of medicinal plants.
• In general, the highest temperature are
experienced near the equator, and temperature
falls with elevation
• i.e Jamaica to have a tropical climate on the coast
and a temperat one in the mountains so sugar
can be cultivated at the coast as it is a lowland
plant while Tea can be cultivated at elevations.
35. • d- Light:
• Plants vary in the amount and intensity of the
light which they rquire.
• The effects of light intensities on the growth
of plants are related mainly to the role of light
in “Photosynthesis”.
• ‘Photoperiodism’:
• defined as the response of plants to the length
of day, or correctly, to the relative length of
day and night.
36. Plants classified into three broad
photoperiodic classes with respect to
their flowering behavior:
• 1- Short-day plants:
• These plants flower only when the daily period of
illumination is shorter than a particular critical length
i.e. Tobacco.
• 2- Long-day plants:
• These plants flower only when the daily period of
illumination exceeds some critical duration i.e. Dill.
• 3- Day-neutral plants:
• These plants flower under any of a wide range of day
lengths i.e. Capsicum.
37. • “Plant nutrients and/or Plant Manures”
• Soil is a mosaic of rock particles, plant roots,
micro-organisms, decaying organic matter
(humus), aqueous soil solution and
interconnecting air passages.
• Soil is a store house of water and minerals
required for growth of plants.
• Soil differs from one another both in physical and
chemical properties.
2- Soil and soil contents
38. • “Absolute water capacity”
• The amount of water which remains in a soil
after any excess has drained away.
• The air capacity of a soil is inversely
proportional to water capacity.
• i.e. Sandy soil are very permeable while clays
possess a high power of absorbing water.
39. Organic Manures
• Manure is a mixture of organic matter, which is
composed mainly of plant remains put under
animals in the stable and ultimately mixed with
the animal urine and other animal excretions and
some of the stable soil.
• Importance of manures:
• 1- Manures are used as fertilizers.
• 2- They block the soil particles together and
improve conditions of growth i.e. organic matter
in soil takes up and holds water in the same ways
as a sponge holds water.
• 3- Manure is of value as a source of nutrient
elements, especially nitrogen.
40. Essential elements commonly supplied by
the soil are divided into 4 groups:
• 1- Main nutrients or Macro-elements:
• Involving nitrogen (N), phosphorus (P) and potassium (K).
• Commercial fertilizer containing one of these elements is
called a simple fertilizer and if containing one of them, a
complete.
• N.B.:
• - Deficiency of (N) produces stunted yellow colour
(chlorosis).
• Deficiency of (P) reduction of plant size and deep green
colour.
• Deficiency of (K) reduction of carbohydrate synthesis.
41. • 2- Active elements:
• Involving calcium, magnesium and sulphur.
• The little amount of which increases plant
growth, but more than adequate amount has
no effect on plant growth.
• 3- Inactive elements:
• Involving sodium, aluminum, silicon and
iodine.
• They have negligible effect on plant growth.
42. • 4- Micro-elements:
• Involving iron, boron, copper, manganese,
zinc, cobalt, lead and molybdenum.
• These are needed within very minute amounts
for plant growth while any rise in this amount
has poisonous effect on plants.
43. 3- Plant growth regulators
• Growth and development of plants is regulated by a
number of chemical substances, which together exert a
complex interaction to meet the needs of the plant.
• Five groups of plant hormones are well established
they are:
-Auxins
- Gibberellins (GA)
-Cytokinins
- Abscisic acid and its derivatives
- Ethylene
44. • They are: - specific in their action,
- active in very low concentrations
• Regulate: - cell enlargement,
- cell division,
- cell differentiation,
- organogenesis,
- senescence and dormancy
• Some are classified as growth regulators while
others as growth inhibitors.
• Growth stimulators: i.e. auxins, gibberellins (GA)
and cytokinins
• Growth inhibitors: i.e. abscisic acid and its
derivatives and ethylene
45. Growth stimulators
• a- Auxins:
• The most important natural one is 3- or β-indole
acetic acid (IAA).
• Typical effects of auxins are:
• 1- Stimulates the growth (cell elongation).
• 2- Ovary growth: IAA alone is not always
sufficient to promote fruit growth but GA may be
needed.
• 3- Cambial activity: the ratio of IAA and GA is
important in determining whether phloem or
xylem tissues were formed by the cambium.
46. • 4- Effects on the formation of secondary
metabolites
• i.e. seedlings and young plant of Mentha piperita
when treated with IAA, gave in the mature plants
an increased yield (30-50%) of oil which itself
contained more menthol.
• 5- The main practical uses of auxins are:
- Low concentrations accelerate rooting of woody
and herbaceous plants.
- Higher concentrations act as selective herbicides
or weed killers.
47. • b- Gibberellins:
• About 40 gibberellins are now known, in higher
plants they are synthesized in leaves and
accumulated in immature seeds and fruits.
• They have the following effects:
• 1- Induce flowering at earlier stages.
• 2- Increase the length of the dwarf varieties of many
plants.
• 3- effects on secondary metabolites
- Volatile oils in case of Citrus, Mentha and many
umbelliferous fruits, the amounts of volatile oils
variably increased
48. - Alkaloids: Belladonna, Hyoscyamus and
Nicotiana produced more alkaloids.
- Glycosides: The total glycosides in Digitalis
were increased.
• c- Cytokinins:
• It is the cell division hormone.
• Their effects are:
• 1- Cell division.
• 2- Cell differentiation and morphogenesis (ratio
of cytokinin/auxin).
• 3- They have inhibitory effect on senescence.
49. Growth Inhibitors
• a- Abscisic acid:
• It is widely distributed in plants.
• It acts by antagonizing GA, blocking synthesis of
DNA and enzymes.
• It induces seed dormancy and inhibits shoot
growth and helps to withstand draft conditions.
• b- Ethylene:
• It was demonstrated that ethylene evolved by
stored apples inhibited the growth of potato
shoots enclosed with them.
