Pharmacognosy & Phytochemistry
Pharmacognosy & Phytochemistry
Pharmacognosy & Phytochemistry
EXTRACTION METHODS
Extraction:
Extraction, as the term is used pharmaceutically involves the separation medicinally
active portions of plants or animal tissues from the inactive or inert components by use
of selective solvents in standard extraction procedures. The products so obtained from
plants or relatively impure liquids, semi-solids or powders, intended only for oral or
external use.
Plant constituents are extracted from both dried and fresh plant materials. The dried
materials must be powdered before extraction. The fresh sample may be directly
extracted homogenized before extraction.
Extraction differs from solution in that the presence of insoluble matter is implied in the
former process.
The principle methods of extraction are:i. Maceration
ii. Percolation
iii. Digestion
iv. Infusion
v. Decoction.
i. Maceration: In this process the solid ingredients are placed in a stoppered container
with the whole of the solvent and allowed to stand for a period of at least three days
(until soluble matter is dissolved), with frequent agitation. The mixture is then strained,
the marc (the damp solid material) passed, and the combined liquids are clarified by
filtration by decontamination after standing.
ii. Percolation: This is the procedure most frequently used to extract the active
ingredients in the preparation of tinctures and fluid extracts. In the BPC general
percolator (a harrow cone shaped vessel open at both ends) is used. The solid ingredients
are moistened with an appropriate amount of specified men strum and allowed to stand
for approximately four hours in a well-closed container, after which the drug mass is
packed in the percolator. Sufficient men strum is added to saturate the mass and top of
the percolator is closed. When the liquid is about to drip from the neck (bottom) of the
percolator, the outlet is closed. Additional men strum is added to give a shallow layer
above the mass and the mixture is allowed to macerate in the closed percolator for 24
hours. The outlet of the percolator is then opened and the liquid contained there is in
allowed to drip slowly. Additional men strum being added as required, until the
percolate measures about three quarters of the required volume, and the mixed liquid
is clarified by filtration or by allowing it to stand and then decanting.
iii. Digestion: This is a form of maceration in which gentle heat is used during the process
of extraction. It is used when moderately elevated temperature is not objective able and
the solvent efficiency men strum increased thereby.
iv. Infusion: An infusion is a dilute solution of the readily soluble constituents of crude
drugs. Fresh infusions are prepared by macerating crude drugs for a short period of time
with cold or boiling water.
v. Decoction: This once popular process extracts water soluble and heat stable
constituents from crude drugs by boiling in water 15 minutes, cooling, staining, and
passing sufficient cold water through the drug to produce the required volume.
Extraction Process
The processes commonly used for the separation and purification of organic compound
are:i. Crystallization
ii. Sublimation
iii. Distillation
iv. Fractional Distillation
v. Distillation under reduced pressure
c. Filtration of Hot solution: The hot solution obtained above is then filtered through a
fluted filter paper placed in an ordinary glass funnel if the quantity of the solution is
large, it takes longer and the crystals may form in the funnel during filtration. To
prevent this, a hot water funnel may be used.
d. Crystallization: The hot filtrated is then allowed to cool undisturbed in a beaker. The
pure solid substance separates as crystals. When a rich crop of crystals has been
obtained, crystallization is complete. Sometimes crystallization does not occur even
after cooling the filtrate for a sufficiently long time. In such a case the crystallization is
induced either by sketching the walls of the beaker with a glass rod or by adding a
few crystals of the pure compound to the solution.
e. Separation and drying of crystals: The crystals are separated from the mother liquor
by filtration. The filtration is generally effected under reduced pressure using a
Buchner (or Hirsch) funnel. When the whole of the mother liquor has been drained
into the filtration flask, the crystals are washed with small quantities of the pure cold
solvent to remove adhering impurities. The crystals are then dried by pressing
between parts of filter paper in a n oven, or in a vacuum desiccator.
ii. Sublimation: Some substances when heated pass. The vapor when cooled gives back
the solid substance. This process is known as sublimation. It is very helpful in separating
volatile from non-volatile solids. It is however of limited application as only a few
substances like naphthalene, camphor, and benzoic acid can be purified by this process.
The impure substance is placed in a large beaker. The beaker is covered with a watch
glass. Heat is applied gently to the beaker, and the resulting vapors condense as crystals
on the bottom surface of the watch glass can be removed after some time and the
crystals collected.
#### Organic substances such as benzoic acid, naphthalene etc., which have high vapor
pressure at temperature below their melting points, can be sublimed relatively quickly.
These can be conveniently purified by the method described above.
Substances which have very small vapor pressure or tend to decompose upon heating are
purified by sublimation under reduced pressure.
The glass apparatus used for sublimation under reduced pressure is shown in the figure.
The chief features of this apparatus are a large heating and a large cooling substance with
a small distance in between. This is necessary because the amount of the substance in the
vapor phase is much too small in case of a substance with low vapor pressure.
iii. Distillation: The operation of distillation is employed for the purification of liquids
from non-volatile impurities.
The impure is built in a flask and the vapors so formed are collected and condensed to
give back the pure liquid in another vessel. The non-volatile impurities are left behind in
the flask.
The apparatus consists of a distillation-flask flitted with a thermometer in its neck
and a condenser at the side-tube. The liquid to be purified is placed in the distillation
flask and the thermometer so adjusted that its bulb stands just below the opening of the
side-tube. This ensures the correct reading of the thermometer of the vapor passing over
to the condenser. A suitable vessel is attached to the lower end of the condenser to
receive the condensed liquid. On heating the distillation flask, the thermometer first
records a rise in temperature which soon becomes constant. At this point which is the
boiling temperature of the pure liquid, most of the liquid passes over. Towards the end
of the operation the temperature rises once again on account of the superheating of the
vapor. The distillation is stopped at this stage and the receiver disconnected.
In case of liquids having boiling points lower than 110, the water condenser is replaced
by air condenser. To patient bumping, it is customary to put a few pieces of unglazed
porcelain in the distillation flask.
While distillation a very volatile and inflammable liquid such as ether, the
distillation flask is heated or a water-bath and not on a wire-gauze. In case of high
boiling liquids, the flask is heated directly with a naked flame.
iv. Fractional Distillation: A mixture of two or more volatile liquids can be separated by
fractional distillation. When their boiling point differs by more than 40, the operation
can be carried with the help of ordinary distillation apparatus. The more volatile liquid
passes over first and collected in a receiver.
When the temperature begins to rise for the second time, the first receiver is
disconnected. A new receiver is attached as soon as the temperature becomes constant
once again. Thus the distillate is collected in fraction and the process is termed fractional
distillation.
When the liquids present in the mixture have their boiling point close to each
other, the separation is best effected by fitting the distillation flask with a fractionating
column which is tern is connected to the condenser. On heating, the vapor of the more
volatile liquid A, along with a little of the vapor of the less volatile liquid B, rise up and
come in contact with the large cooling surface of the fractionating column. The vapors of
B condense first wing down the column meets the fresh hot ascending vapor. It snatcher
more of B from the vapor mixture and gives up any dissolved vapor of A. This process is
repeated at every bulb of the fractionating column so that the vapor escaping at its top
consists almost exclusively of A and the condensed liquid following back into the
distillation flask in rich in B. if necessary the process can be repeated with the distillate
and the liquid left in the distillation flask.
The used of the fractionating column has found a remarkable application in
modern industry especially in the distillation of petroleum, coal-tar and crude alcohol.
v. Distillation under reduced pressure: In case of organic liquids which decompose before
their boiling point is reached, the distillation is carried under reduced pressure when the
liquid boils at a lower temperature.
1. Claisen Flask, having two necks. It is filled with long down jet dipping in the liquid to
be distilled. During the distillation, a steam of bubbles rises through the capillary of this
jet and presents bumping which is so pronounced here than in ordinary distillation.
2. Condenser, connected with the claisen flask on the one hand and a filtration flask,
serving as a receiver, on the other.
3. Manometer, The receiver flask is connected to an exhaust pump through (a) a mercury
manometer which tells the pressure under which the distillation is being carried, and (b)
a trap, to eliminate any condensed liquid.
The pressure in the apparatus is reduced with the help of a water pump. Whenever a
lower pressure is desired, the water pump is replaced by a mercury pump.
An important application of this process is the recovery of glycerol from spent-lye
in soap industry. Glycerol decomposes at its boiling point (298) by can be distilled
unchanged at 12 mm pressure when it boiled at 180. Another application of vacuum
distillation is the concentration of sugar juice under reduced pressure.
vi. Steam Distillation: Many substances that are insoluble in water and volatile in steam
can be purified by distillation in a current of steam. The non-volatile impurities are left
behind in the distillation flask.
The impure mixture together with some water is placed in a round-bottom flask
which is then connected to a steam-generation on one side and a water condenser on the
ether. The flask is adjusted standing position so that no droplets of the mixture splash
into the condenser on brisk boiling and bubbling of steam. The mixture in the flask is
heated and then a current of stem passed into it. Heating of the flask is controlled so as
to avoid unnecessary condensation of steam in it. Steam ricks up the volatile substance
from the mixture and passes into the condenser. The distilled collected in the receiver
consists of a mixture of water and the organic substance. The distillation is stopped when
the droplets or the solid particles of the organic substance curse to appear in the
condenser.
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P = P 1 + P2
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IMPORTANCE OF CHROMATOGRAPHY
i. It is one of the most important analytical tools.
ii. It serves as a means for the resolution of the separated substances.
iii. It permits the separation and partial description of unsuspected and unknown
substances.
iv. It is an indispensible laboratory method in all sciences dealing with chemical
substances and their reactions.
v. It is among the most selective and most widely applicable separator- techniques yet
devised.
ORGINAL CONCEPT OF CHROMATOGRAPH
In its classical form, as first described by a Russian botanist, M. Ts wett in 1906,
chromatography is a method of separating substances by filtering their solutions through
a column of a finely powdered adsorbent, filled into a glass tube, then washing
(developing) the column with a solvent. This results in the separation of the various
components of the mixture due to their selective adsorption. The separated substances
from distinct zones in the column. They are then separated by cutting the column or are
washed down fractionally. Tis original concept of chromatography was suitable for only
colored substances, like pigments. Over the years, the chromatographic techniques have
undergone tremendous modification and improvement making separating not only
colored substances, but also closely related colorless substances of all description.
CLASSIFICATION AND NOMENCLATURE OF CHROMATOGRAPHIC PROCESS
Chromatography is a separation technique where separation is affected by a number of
ways and by the application of various may be summarized as follows:a. Separation by adsorption.
b. Separation by Partition
c. Separation by ion exchange
d. Separation by electric charge
e. Separation by particle size difference.
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In all these methods in separation two different phases are involved:1. Stationary Phase: Which may be a solid or liquid series as the carrier or holder of
the mixture to be separated, is called the stationary phase.
2. Mobile Phase: Which may be a liquid or a gas, moves through the stationary
phase pushing or carrying the compounds of the mixture over it at different
speeds depending on the affinity of the individual components for the two phases.
This moving phase is called the mobile phase.
On the basis of separation principles chromatographic process may be broadly divided
into the following major groups:(i) Adsorption chromatography: In this technique, a pure solid in powdered from is used
as the stationary phase and a liquid or gas as the mobile phase.
(ii) Partition chromatography: In this case, a liquid coated on an inert solid support
serves as the stationary phase and a liquid or a gas as this mobile phase.
(iii) In-exchange chromatography: In this method, separation in carried out on some solid
ion-exchangers by the use of an aqueous solution as the mobile phase.
(iv) Elect chromatography or Electrophoresis: In electrophoresis, electric charge is used to
effects separation of the components of a mixture. This can be used either as partition
or as adsorption chromatography. In this technique, an electrolyte serves as the mobile
phase or the medium.
(v) Gel filtration: in this method of separation, porous solids with a defined narrow
distribution of pores are used as the stationary phase and a liquid as the mobile phase.
This is also called a molecular sieve process or exclusion chromatography as the
separation of the different components of a mixture depends on the size of their
molecules.
Most of these chromatographic processes may be carried out in a number of different
ways. They can be carried out by using columns of adsorbents or on this layer of
adsorbents spread on glass slabs, or on paper, or by the use of gases. Depending on
the specific technique employed chromatographic methods are also variously named--
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the absorbent on the plate a suitable binding agent or binder is used along with the
adsorbent.
PREPARATION OF THESE PLATES
In preparing the plates the adsorbent, with or without a binder, is made into slurry with
a proportionate quantity of distilled water. The slurry is then quickly poured into a
spreader. This consists of a rectangular box open at the top and a hollow cylinder which
can be rotated through 180 the slurry empties and passes out through an adjustable slit
at the bottom of the spreader to give a layer of desired thickness. The plates to be coated
are faced edge to edge on a stable support. The spreader is held over the first plate and
when the slurry starts coming out on rotating the cylinder, the spreader is drawn across
the plates.
The coated plates are left far while on the support for setting and air drying of the
adsorbent. They are then carried on same suitable racks to an oven where they are
activated by healing at a temperature of 110 to 135 for half an hour to one hour. After
activation the plants are stored in a deflector. The usual thickness for a thin layer of
adsorbents used for analytical work is 250 micron.
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achieved by liming the inner side of the tank with a filter paper or cloth soaked with the
mobile phase. After dipping the plate the tank should be closed firmly and left
undisturbed until the operation is complete. The solvent or mobile phase runs along the
thin layer in an ascending manner due to capillary action. As the mobile phase moves up
it carries the components of the mixture along with it. They move at different speeds
depending on their affinities for the mobile and stationary phases and are thus resolved
into separate spots. When the solvent reaches or reasonable height the operation is
stopped, the solvent front marked and the plate is dried using suitable techniques.
Column Chromatography
The adsorption or partition chromatographic separations are carried out on a column of
adsorbents placed in a glass or metallic tube.
It has been defined as uniform percolation of a fluid through a column more or less finely
divided substance which selectively retards certain components of the fluid.
In the column method, many adsorbents have been used such as----- sucrose, talc, calcium
or sodium carbonate, activated alumina, silicic acid and fullers earth.
Solvents/(eluents):
Petroleum
ether,
carbon-tetrachtoride,
carbondissulfide,
ether,
acetone, alcohol, water and mixtures of acids and bases in water, alcohol and pyridine.
The absorbent is packed uniformly into a suitable glass or quartz tube, and the solution
of the drug or substance in a small amount of eluent is passed through the column.
According to their adsorption coefficients, the various constituents in the drug or
substance are removed from the solution and are adsorbed in transverse bands at varying
distances from the top of the column. Each component progresses downward at a
characteristic rate.
Lhpon drying, the resulting column consists of a series of bands separated components
and is known as the chromatogram, this is removed from the tube as a single column and
then divided into the separated bonds for individual analysis.
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Depending on the particular activity of the constituent and on the other constituents
or ingredients with which it is associated, certain principles may be placed in one or the
other category.
Pharmacologically active constituents:These are those to which the therapeutic activity of the drug is attributed.
They may be either single chemical substances or mixtures of principles, the
separation of which is neither practical nor advantageous.
The single chemicals are exemplified by sugars, starches, plant acids, enzymes,
glycosides, alkaloids, proteins, hormones, and vitamins.
The mixtures include fixed oils, fats, waxes, volatile oils, resins, oleoresins, gum-resins
and balsams.
Active constituents and the drugs containing them are:
Carbohydrates and Related Compounds:Compounds composed of carbon, hydrogen, and oxygen as polyhydroxy aldehyde or
ketonene alcohols, sucrose, lactose, corn starch, traganath, agar, acacia, pectin.
Carbohydrates are classified according to their constitution.
Those having 18 carbon atoms (C18H32O16) are called Tri saccharides etc.
Such simple carbohydrates, because of their solubility and sweet test are commonly
referred as sugars.
The more complex, high molecular weight polysaccharides can usually be
hydrolyzed to a component hexose and are therefore called hexoses.
Starch which yields glucose is known as a glucosan. Insulin yielding Fructose is
known as a fructose.
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Glycosides are compounds that yield, upon hydrolysis, one or more sugars among the
products of hydrolysis. The most frequently occurring sugar is Dglucose, cynarose
and other sugars are found as components of glycosides.
Chemically, the glycosides are acetyls in which the hydroxyl of sugar is considered with a
hydroxyl group of the non-sugar component, and the secondary hydroxyl group is
considered within the sugar molecule itself to form an oxide ring. More simply, they may
be considered as ethers. The non-sugar component is known as the glycine; the sugar
component is called the glycine.
Both alpha & beta glycosides are possible drugs containing glycosides, which liberate
physiologically active constituent only upon hydrolysis and do not constituent only upon
hydrolysis and do not contain it in the free state, are sometimes known as Reactionary
Drugs.
Using
the
nature
of
chemical
the
aglycone
group as a basis of systematization, the classification of the glycoside containing drugs is: 1) Cardioactive group
2) Anthraquinone Group
7) Alcohol Group
3) Saponin group
8) Aldehyde Group
4) Cyanophore Group
9) Lactone Group
5) Thiocyanate Group
6) Flavanol Group
11) Others
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1) Cardioactive Glycosides:
The members of this group are characterized by their highly specific action on cardiac
muscle, increasing tone, excitability and contractility steroidal glycosides, which occur in
Digitalis, strophanthus, squill etc.
2) Anthraquinone Glycosides:
A number of glycosides related to anthracene are present in such drugs as Cascara
Sagrada, Frangula, Aloe, Rhubarb, Indian Rhubarb, Senna, Chrysarbin and Cochineal.
With the exception of Chrysarobin and Cochineal, these drugs are employed as
cathartics.
The glycosides, on hydrolysis, yield aglycones which are di, tri, or tetrahydroxy
anthraquinones or modifications of these compounds.
Example:
Frangulin
Fairbarin has shown that, without the sugar groups, free anthraquinones exhibit little
therapeutic activity. The sugar moiety is essential because it serves to transport the glycon
to the site of action in the large intestine.
Without sugar groups, the aglycone, would largly disappear during metabolism. The
compounds give a positive Borntrager reaction and are responsible for the laxative action
of these drugs.
Biosynthesis of Anthraquinone Glycosides: - Feedings of labeled acetate to penicillium
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A poly--ketomethylene acid intermediate is probably first produced and then gives six
to
the
various
oxigenarated
aromatic
compounds
following
intramolecular
condensations.
3) Saponin Glycosides:
This group of glycosides is widely distributed in the higher plants.
Saponins are characterized by forming colloidal solutions in water which foam upon
shaking\. They have a bitter, acrid taste and drugs containing them are usually
sternutatory and other wise irritating to the mucous membrane.
They destroy red blood corpuscles by hemolysis and they are toxic espically to cold
blooded animals, many having been used as fish poisions.
Upon hydrolysis they yield an aglycone known as a sapogenin. The sapogenins from
readily crystallizable compounds upon crystallization by which means they may be
purified and studied. The most poisonous saponins are often called sapotoxins.
Biosynthesis of Saponin Glycosides: - Saponin glycosides are divided into two different
types based upon the chemical structure of their aglycones (sapogenins).
Neutral salonins are derivatives of steroids with spisoketal side chains; the acid saponins
possess triterperiod structures.
A brance occurs after the formation of the triterpenoid hydrocarbon saequence, which
leads to steroids in one direction and to cyclic triterpenoids in the other.
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common
cyanophore
glycosides
are
derivatives
of
mandelonitrile
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5) Thiocyanate Glycosides:
The seeds of several cruciferous plants contain glycosides, the aglycones of which are
thiocyanats. Principal among these glycosides are sinigrin from black nuestard, sinalbin
from white musters and gluconapin from rape seed.
When hydrolyzed by the enzyme myrosin, they yield the mustard oils.
Biosynthesis of Thiocyanate Glycosides: - Aglycones of thiocyanate glycosides may consist
of either aliphatic or aromatic derivative. Isotope feeding studies have shown that at least
one example of the former type is biosynthesized via the acetate pathway and one of the
iatter type via the shilamic acid route.
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Studies with phenylanaline labeled in both the --carbons and the mitrogen atom of the
alahive moiety have shown that the side chain of the acid is decarboxylated and then
incorporated as unit into glucotropaeolin in tropaeolum majus.
6) Flavonol Glycosides:
The glycosides rutin, hesteridin and quercitrin are related to the flavones.
Chemically, rutin 3, 3, 4, 5, 7 pentahyhoxyflavae-3-rutinoside. Thus, it is associated
with the pigment glycosides.
Many, if not all, of the red, yellow, violet and blue pigments in plants either exist as
glycosides or are derived from them. The pigment glycosides are usually classified into
the three following types: a) The, Anthraqui, suchas alizarin from madder root
b) The flavoncs or xanthones most of the yellow pigments found in plants are
flavones, such as chrysin.
c) The anthrocyanins and Anthoxan thirs these include most of the red, blue and
violet pigments found in plants.
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flavonoids, are examples of products derived from both of the major path ways leading
to the synthesis of aromatic compounds in biological systems.
One six-carbon fragment of these C6-C3-C6 compounds derives from acetate metabolism
and the rehaining nine-carbon portion from the shikimic acid (phenylpropanoid)
pathway. The following scheme indicates how the C 8-C3 portion.
Probably in the oxidation state of a cinnamic acid, combines with these molecules of
acetate to form a C15 chalcone intermediate and then a flavanone.
Introduction or removal of hydroxyl groups from rings A & B results in the production of
a large number of quantities.
Flavanols are probably first formed by introduction of the hydroxyl group in position 3
and then dehydrogenation of positions 2 & 3 results in the production of flavonols.
7) Alcohol Glycosides:
Salicin is an alcoholic glycoside which hydrolyzes into saligenin (salicyl alcohol)
Another glycoside populin (benzylsalicin) is associated with solution in barks of the
salcaceac.
Coneferin: - A glycoside found in the cambial layer of many pines, yields coniferyl
alcohol on hydrolysis.
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Biosynthesis of Alcohol, aldehyde, lactone, and phenol Glycosides: - The aromatic nuclei
of some compounds (alcohol, aldehyde, lactone and phenol glycosides) derived from C 6 C3 precursors formed via the shikimic acid pathway.
8) Aldehyde Glycosides:
Salinigrin
occurring
in
Salix
discolor
consists
of
glucose
contained
with
m-
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9) Lactone Glycosides:
Coumarin is widely distributed in plants, glycosides containing coumarin as such are
raised several of its hydroxyl derivatives however are known. None are of particular
medicinal importance. The -pyrone structure of coumarin may be illustrated as follows.
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VOLATILE OILS
VOLATILE OILS:Volatile oils are the odorous principles found in various plant parts. Because they
evaporate when exposed to the air at ordinary temperatures, they are called volatile oils,
ethereal oils or essential oils.
The last term is applied since volatile oils represent the essences or the active
constituents of the plants.
Volatile oils are colorless as a rule,
Particularly when they are freshly obtained, but on long standing they may oxidize and
resinify, thus darkening in color.
To prevent this, they should be stored in a cool, dry place in tightly stoppered,
preferably in full amber glass containers.
In the plant parts they occur in glandular hairs, modified parenchgmatous cells, oil
tubes called vital and in some special oil ducts.
Chemical constituents of volatile oils may be divided on the basis of their biosynthetic
origin into two broad classes: 1) Terpene derivatives formed via the acetate mevalonic acid pathway.
2) Aromatic compounds formed via the shikimic acid phenylpropanoid route.
METHODS OF OBTAINING VOLATILE OILS:Volatile oils are usually obtained by distillation of the plant parts containing the oil, the
method depending on the condition of the plant material.
Three types of distillation are used: i. Water Distillation.
ii. Water and Steam Distillation and
iii. Direct steam Distillation.
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WATER DISTILLATION
It is applied to plant material that is dried and not subject to injury by boiling.
Turpentine oil is obtained in this manner. The crude turpentine oleoresin is introduced
into the distillation chamber and subjected to heat until all volatile matter is condensed
in the condensing chamber.
Turpentine oil, is not affected by this amount of heat.
WATER AND STEAM DISTILLATION
It is employed for substances that may be injured by boiling. In the case of dried material
(cinnamon, clove), the drug is ground and then covered with a layer of water, and steam
is passed through the macerated steam is passed through the macerated mixture. Since
the oil might be impaired by direct boiling, the steam is generated elsewhere and is piped
into the container holding the drug. The oily layer of the condensed distillate is separated
from the aqueous layer, and the oil may be marketed with or without further processing.
DIRECT STEAM DISTILLATION
Applicable to fresh plant drugs (peppermint, bspearmint), the crop is cut and taken
directly to the distilling chamber. Steam is forced through the fresh carrying the oil
droplets to the condensing chamber.
During steam distillation certain components of a volatile oil tend to hydrolyze where
as other constituents are decomposed by the high temperatures.
Ideal distillation methods utilizing steam should provide for the diffusion rate of steam
and water through plant, membranes to be as possible and should thus keep the
hydrolysis and decomposition at a minimum.
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MEDICAL AND COMMERCIAL USES: Many crude drugs are used medicinally because of their volatile oil content; in numerous
cases, the volatile oils separated from the drugs are used as drugs in themselves.
Various crude drugs are powdered and are employed as spices and condiments.
The most common use for the volatile oil drugs as well as for the separated oils is
flavoring purposes. They all possess a carminative action but a few possess additional
therapeutic properties. In addition to their pharmaceutical use, the volatile oils are
employed widely as flavors for foods and confections and in the spice, perfume and
cosmetic trades. Many volatile oils possess antiseptic properties.
CHEMISTRY OF VOLATILE OILS:Most volatile oils consists largely of trepnes which are isomeric hydrocarbons would
naturally account for the presence of alcohols, aldehydes, ketones, phenols, phenolic
ethers; esters and oxides. Since these oxygenated compounds are responsible for the
characteristic odors, testes and therapeutic properties of the volatile oils, if follows that a
chemical classification of the oils should be based on the principal chemical constituents.
The following are the divisions in which volatile oils-contains drugs are placed:
1) Hydrocarbons: Cubeb, Pepper, Turpentine oil.
2) Alcohols: Peppermint, Cardamom, Coriander, Rose oil, Orange flavor oil, Pine oil
3) Aldehydes: Cinnamon, Lemon peel, Citronella oil, Bitter almond oil.
4) Ketones: Camphor, Spearmint, Caraway, Buchu.
5) Phenols: Thyme, Clove, Marcia oil, Creosote, Juniper Tar.
6) Phenolic Ethers: Amine oil, Fennel oil; Myristica, Sassafras.
7) Oxides: Chenopodiam oil; Eucalyptus oil.
8) Esters: Levered oil; Rosemary oil, Bergamot oil; Mustard oil; Gaultheria oil.s
9) Others: Angelica herb.
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ALKALOIDS
Alkaloids are organic nitrogenous compounds. All do occur in plants, but some are found
in animals, and practically all have been represented in the laboratory by chemical
synthesis.
Alkaloids may occur in various parts of the plant in seeds (Nux vomica areca) , in
fruits (black papper, conium), in leaves (belladonna leaf, hyoscyamus), in rhizomes and
roots (ipecae, hydrastis), and in barks (cinnhona, pon-cgranate)
The names of the alkaloids are obtained in various ways: 1. From the genetic name of the plant yielding them.
2. From the common name of the drug yielding them.
3. From the specific name of the plant yielding them.
4. From the physiological activity.
5. Occasionally from the discoverer.
Alkaloids usually contain one nitrogen atom although some like ergotamine may contain
up to five. The nitrogen may exist as a primary amine (RNH 3), as a secondary amine
(R2NH) or a tertiary amine (R3N).
Such compounds are basic, but the degree of basicity varies greatly depending
upon the structure of the molecule and the presence and location of other functional
groups.
For the most parts the alkaloids are insoluble or sparingly soluble in water but reacts with
acids to form salts which are usually freely soluble.
The free alkaloids are usually soluble in ether or chloroform or other relatively
non-polar, immiscible solvents in which, however, the alkaloidal salts are insoluble.
Most of the alkaloidal salts are crystalline solids, although a few are amorphous, and an
additional few which lack oxygen in their molecules are liquids.
Alkaloids are usually classified according to the nature of the basic chemical structures
from which they derive.
35
Important ring structures present in alkaloidal and other drugs. Various schemes for the
classification of alkaloids have been suggested. The following plan is based on the ring
structure or nucleus of the chief alkaloid in the plant drug
1) Pyridine piperidine combined group.
2) Tropane Group.
3) Quinoline Group
4) Isoquinoline Group
5) Indole Group
6) Imidazole Group
7) Steroidal Group
8) Lupinane Group
9) Alkaloidal amine Group
10) Purine Group.
36
(1) Pyridine Piperidine Alkaloids: Upon reduction the tertiary base pyridine is converted
into the secondary base piperdine is converted into the secondary base piperdine. These
two nuclei from the basis of this group.
The important alkaloidal drugs drugs and their alkaloids which are classified in this group
are: Areca, Areccoline Hydrobromide, Lobelia, Lobelin, Pomegranate, pelletierine
Tanate, Comium, Coniine, Piperine, Nicotine, Trigonelline.
37
Pyrrolidine occurs free in small quantities in tobacco and opium and is tetrahydropyrrole.
To this group belong such alkaloids arehygrine from Erythroxylon coca and stachydrine
from stachus luberifera.
38
(3) Quinoline Alkaloids: Alkaloids congaing quinoline as the principal nucleus include
those obtained from Cinchona:- quinine, quinidine, cinchomine and cinchomidine; and
viridicatin from penicillium viridicatum.
Cinchona.
(4) Isoquinoline Alkaloids: The isoquinoline structure occurs in a considerable number of
alkaloids in widely separated plant families.
Although the more important opium alkaloids exhibit a phenanthrene nucleus, the
majority of its alkaloids have the isoquinoline ring structure.
Phenanthrene
alkaloids
are
derived
biosynthetically
from
benzylisoquinoline
39
The important drugs and their alkaloids of these group are: - Ipecae, Emetine, Hyclrastis,
Hydrostine, Sanguinaria, Curare, Tubocurarine, Berberis, berberine, opium and its
alkaloids.
(5) Indole Alkaloids: A number of important alkaloids possess an indole ring as part of
their structure.
Strychnine and brucine (dimethoxystrychnine) from Nux Vomica and physostigmine
from physostigma belong to this group.
Strychmine and brucine contain in addition a quinoline mucleus so it may be
classified in the quinoline group also
Alkaloids:
The
steroidal
alkaloids
are
characterized
by
40
the
ctclopentenophenanthrene nucleus.
They are apparently either formed from cholesterol, or they and cholesterol have a
common peecursor.
The important drugs and their alkaloids of this group are veratrum vimide,
veratrum album, rotoveratxine, aconite, aconitine and larruper.
(8) Lupinane Alkaloids: Sparteine, a liquid alkaloid, is the only medical representative of
this group. It is derived from Scoparius. Acrystalline alkaloid, lupinine, is obtained.
(9) Alkaloidal Amines: The alkaloids in this group do not contain heterocyclic nitrogen
atoms.
Many are simple derivatives of phenylethylamine and as such are derived from the
common amino acids phenylalamine or tyrosine, Ephedmine, Colchicine.
41
(10) Purine Bases: The purines are derivatives of a heterocyclic nucleus consisting of the
six membered pyrimidine ring fused to the five membered imidazole ring.
Purine itself does not occur in nature. But numerous derivatives are biologically
significant.
The pharmaceutically important bases of this group are all methylated derivatives of
2,6 dioxypurine (xanthine).
Coffein in 1, 3, 7 trimethylxanthine, theophylline in 1,3- dimethylxanthine.
42
FIBERS
Fibers are used for dressing purposes both in their normal forms and in woven or fabric
forms. Fibers that are useful in wound management and healing include both natural and
artificial or synthetic fibers. Natural fibers may be of plant or animal origin.
Plant fibers include epidermal trachoma, such as cotton, and other fibrous tissues of
plants, such as cotton, and other fibrous tissues of plants, such as phloem fibers (e.g.,
jute) and pericyclic fibers (e.g., Flax and Hemp).
Fibers of animal origin are derived from some animal products such as wool and silk.
Artificial fibers, prepared by processing or regenerating some tissue elements of plant
animals such as wool cellulose (e.g., Rayons, Cellulose, Wadding and Alginate fibers) are
also frequently used in wound management and surgical dressings. Some synthetically
43
prepared fibers, such as nylon and terylene, have also been used for dressing wounds and
burns.
The various groups of fibers used for surgical dressings may be conveniently summarized
in the following way: -
COTTON
Synonyms: Raw cotton, Cotton wool, Absorbent cotton.
Biological Source: Cotton consists of the epidermal trichomes of the seeds of Gossypium
herbaceum Linn.
Family: malvaccae.
Preparation of Raw cotton and Absorbent cotton Wool: Bolls of cotton are collected
from the ripe and dehisced fruits of gossypium.
44
The trichomes are separated from the seeds by a ginning process using a machine
called a gin in which the trichomes are drawn through a narrow space. The masses of
these separated trichomes constitute raw cotton. Raw cotton thus prepared contains
impuriries, chiefly coloiring matter. And about 0.6% of wax and oil, which form a thin
film around the filters and render them the non-absorbent. Raw cotton is then variously
treated, combed and spinned to convert it to yarn or thread, which are woven to make
fabrics and cloths.
Absorbent cotton on wool: Is prepared from various cotton wastes obtained during the
processing of raw cotton for waking gains; The wastes are loosened and then boiled for
10 15 hours under a pressure of about 30lbs in a dilute solution of caustic soda and ash.
This treatment removes the fatty cuticle and renders the trichomes absorbent. The boiled
material is then washed thoroughly with water, bleached with dilute sodium
hypochlorite solution and treated with very dilute hydrochloric acid.
The balanced mass of fibers is then dried, loosened, scotched and carded by using
appropriate machines.
The resultant product is a thin continuous film of absorbent cotton wool. Several such
films are superimposed on one another and rolled.
Constituents: Raw contains about 90% of cellulose and small amounts of wax, fat,
remains of protoplasm, ash. Absorbent cotton is almost pure cellulose.
Uses: Cotton is used as the chief material for many surgical dre3ssings. It is also used as a
filtering medium and an insulating material.
JUTE
Synonyms: Gunny.
Preparation of Jute Fiber: Jute plants are normally straight and unbranched. They are cut
from the base when the plants are in flower, tied into small bundles, stacked and soaked
in stagnant water for about three weeks for retting. The stacks are covered with straw or
water hyacinths to keep them wet and to protect from direct sunlight. When the stem
45
bark is well-macerated by the retting process, the stands of the phloem fibers are
separated manually from the wood and washed free from the surrounding softer tissues
and other dirts thoroughly in clean water. The fibers are then dried in direct sunlight and
made into small bundles. Jute fiber is exported in bales made by hydraulic pressure.
Constituents: Jute fibers are composed of 53% cellulose and 22% hemicellulose and
contain 11% of lignin, 1% of fats and waxes and 1% of ash.
Uses: In pharmacy jute is used for the manufacture of medicated tows, for padding
splints, as a filtering or straining medium and for soaking fluids. Other industrial uses of
jute include the manufacture of ropes, Gunny bags, carpet backings and yarns for some
fabrics.
FLASK
Preparation of Flax: The plants are uprooted by hand just about the fruits, tied in sheaves
and left to dry in the field. The dried plants then undergo a ripping process to remove
the capsules. After which the stems are tied in bundles and subjected to a retting
process.
When retting is complete, the stalks are dried in the sun, broken into pieces in a mill
and pieces of the xylem tissues removed by the teeth of a sketcher. The residual bark
from the stem is then mechanically combed to make the fibers parallel.
Constituents: Flax is made up to pecto cellulose.
Uses: Flax is used as a filtering medium for some preparations. It is rarely used in the
manufacture of lint.
WOOL
Synonyms: Animal wool, Sheeps wool.
Preparation of Wool: The hairs are cut from the sheep at appropriate intervals and dirt
removed by beating on a sieve screen. The dirt-free hairs are then thoroughly cleaned by
washing with soap and sodium carbonate.
46
SILK
Preparation of Silk: The cocoons, a covering of filaments produced by the larvae of the
silk warm around themselves before passing to their pupal stage. They are then taken or
steamed to kill the pupal.
The cocoons are then placed in hot water to soften and removed partly the natural
gum of the silk filaments. The ends of the filaments from two to six cocoons are then
caught up. A number of these are twisted together to form a single thread of raw silk.
This raw silk is made up into hanks for processing into fibers.
Constituents: The mass of the silk fiber is made up of the protein fibroin, coated
externally by another protein serein or silk gum, which cements the fiber together. The
proteins of silk do not contain sulphur.
Uses: The pharmaceutical use of silk includes manufacture of ligatures, oiled silk and
some sieves.
CELLULOSE WADDING
Synonyms: Wool cellulose, Chemical wool pulp.
Source: Cellulose wadding is prepared from bleached sulphite wood pulp obtained from
the wood of various conifers.
Constituents: Cellulose wadding consists almost entirely of pure cellulose.
Uses: Cellulose wadding is used as the chief material for many surgical dressings.
47
RAYON
Synonyms: Regenerated cellulose, artificial cellulose
Constituents: It consists of 0.3% of sulphur and yields about 0.2-0.3% of ash.
Uses: Lint, gauze, net and other surgical dressings are made from viscose rayon.
ALGINATE
Synonyms: Calcium Alginate fibers.
Uses: Calcium alginate fibers are used to prepare gauzes for absorbable haemostatic
dressings and bacteriological swabs.
NYLON
Sources: Nylon is a synthetic fiber, chemically synthetized polymerization from long
chain adipic acid and hexamethylenediamine. The polycondesation product in molter
condition is pumped through a spinning machine and the resultant filaments are colddrawn to increase their length.
Description: Nylon fibers are smooth, solid and cylindrical.
48
GAUZES
Gauzes are usually absorbent dressings principally made from cotton fabrics.
They can be either medicated or unmediated. Medicated gauzes and also other
medicated dressings are prepared by immersing the fabric in a solution of the
medicament and drying off the solvent. Gauzes used for surgical dressings may be
conveniently grouped as follows: -
UNMEDICATED GAUZES
1) Absorbent Gauze: This gauze consists of a plain-wove cotton fabric, 36 inches wide,
with not less than 19 threads per inch in the warm and 15 in the weft ( ). One
square yard of the gauze weighs not less than 11.5g.
49
2) Absorbent Ribbon Gauze: This is finer than not less than 30 threads/inch in the warm
and 25 in the weft. A 2 in by 6 yard piece of the gauze weighs not less than 12.3g.
3) Absorbent Gauze Tissue: This is a sleeve-like which encloses a thick layer of absorbent
cotton wool. The fabric used in this gauze has 12 threads/inch of weft. One round of this
gauze must have a superficial area of not less than 1800 square inch.
4) Cellulose Tissue: This is also tubular absorbent gauze like the gauze tissue. But it
encloses a thick layer of cellulose wadding instead of absorbent cotton wool.
Medicated GAUZES
1) Boric Acid Gauze: It contains 3 to 7% of Boric acid, is tinted pink with a suitable lie.
2) Euflavine Gauze: This gauze is medicated with 0.1% of Euflavine.
3) Double Cyanide Gauze: This contains a mixture of Mercury cyanide (0.5 to 1.5%) and
zinc cyanide (1.5 to 3.0%) and is tinted purple with a suitable dye.
4) Iodoform Gauze: This medicated gauze contains 4 to 6% of Iodoform.
5) Trinitrophenol Gauze: It contains 1.5 to 2.5% of trinitrophenol.
6) Capsium: This is tubular absorbent gauze which encloses capsicum.
BANDAGES
Bandages are continuous length of fabrics and contain no joins. Their edges are evenly
cut, parallel with the warm threads. They are reasonably free from loose threads.
Bandages are chiefly made from plain or treated cotton cloths, but some of them are also
made from wool. In addition to these, there are some bandages which are made from
fabrics containing a mixture of both cotton and wool. Bandages may therefore be
grouped into four categories according to the type of fabrics they are made from as
follows: -
50
BANDAGES
Plain cotton Cloth Bandages
1. Open-wove Bandage
2. Bleached Calico Bandage
3. Unbleached Bandage
4. Muslin Bandage
1.
2.
3.
4.
Battiste
Jaconet
Oiled Cambric
Zinc paste Bandage
1. Flannel Bandage
Wool-containing Bandage
2. Domette Bandag
3. Crepe Bandage
Silk Bandage
2) Bleached Calico Bandage: This is a very closely woven white bandage containing 67
threads/inch in the warp and 58 inch is the weft. A 2 4 yard bleached calico bandage
weighs not less than 13.6gm.
3) Unbleached calico Bandage: This bandage contains 65 threads/inch in the warp and 60
in the weft. A piece of A 2 4 yard size of this bandage weighs not less than 16.2gm.
4) Muslin Bandage: This is a bleached bandage of fine threats band may be regarded as
very closely woven absorbent gauze. It contains 48 threads/inch in the warp and 30 in
the weft. One aquare ft of this bandage weighs not less than 3.25gm.
51
the warp (not less than 40/inch) and wool thread in the weft (not less than 22/inch), 2 6
yd of this bandage weighs not less than 28.5gm.
3) Crepe Cambric: This bandage also consists of a mixed fabric, which contains both
wool and cotton threads in the warm and only cotton threads in the weft. However, it
contains not less than 33.3% of wool, which is responsible for its crepe nature.
When fully extended, the bandage must measure not less than twice the length of
its unstretched condition. It must return to not more than 2 3 of the fully extended
length after being held fully stretched for one minute.
52
Silk Bandage
Silk fabrics are used to prepare some special type of surgical dressings.
Oiled Silk Bandage:
This bandage consists of a pure silk fabric having 120 threads/inch in the warp and 85 in
the weft. The bandage is rendered completely waterproof by treating the fabric with a
suitable drying oil or an oil-modified synthetic resin. It may be colored green with a
suitable dye.
LINTS
Lints are medicated or unmedicated absorbent surgical dressings. They are made of plainwove absorbent cotton fabrics. The threads in the warm of the lint-fabrics are raised to
form a nap. They contain not less than 39 threads/inch in the warp and 24 in the weft.
230 to 250 square inch superficial area of the lints should weigh about 28.35gm.
The following medicated lints are available: 1) Boric Acid Lint: This contains 3 to 7% of boric acid, and is tinted with a suitable dye.
2) Euflavine Lint: This type of link contains about 0.1% of euflavine.
PLASTERS
Plasters are a kind of adhesive bandage made from bleached cotton fabrics. An adhesive
compound is spread on one side of the bandage to make it stick to the skin. Plasters may
be either medicated or unmediated. Some common plasters include: 1) Rubber Adhesive Plaster: This is a bleached cotton fabric of prescribed standard,
prepared with an adhesive compound spread on one side and waterproofed with rubber
on the other side.
2) Zinc Oxide Plaster: This is similar to rubber adhesive plaster, but medicated with 20 to
30% of zinc oxide added to the adhesive compound.
53
3) Elastic Adhesive Plaster: This consists of medicated elastic cotton fabrics spread with an
adhesive compound which contains 20 to 30% of zinc oxide.
4) Plaster of Paris Bandage: This is also a medicated cotton fabric plaster, rendered
adherent to the skin by a suitable adhesive. This bandage is impregnated with at least
80% of exsiccated calcium sulphate.
SERGICAL DRESSINGS
This group of surgical dressings includes some standardized compound dressings
described in the British Pharmaceutical Codex and other official publications. These
dressings are prepared ready for use and consists of a pad of medicated cotton wool,
gauze or lint stitched to an open-wove bandage at certain distance from one end. The
longer end of the bandage is rolled and placed inside the pad and the other end is
wound round the rolled pad. The complete dressing is wrapped in impermeable paper
and sterilized.
However, in case of standard elastic adhesive dressings, the pad is fixed to a base of
elastic adhesive cotton fabric, and no bandage is required. This type of standard dressings
is not sterilized.
The standard dressings of B.P.C are numbered 1 to 15 and variously named as follows: Standard Dressing No. 1
This dressing is also known as Double Cyanide Dressing and consists of separate pieces of
double cyanide gauze, Absorbent cotton wool and opens-wove bandage, all wrapped
together and sterilized.
Standard Dressing No. 2
This standard dressing, which is also known as Fomentation Dressing, consists of separate
pieces of Boric Acid lint, Absorbent Cotton wool and an open-wove bandage, all
wrapped together and sterilized.
54
55
VITAMIN A
Vitamin A, the anti-infective, antixerophthalmic vitamin and its naturally occurring
isomer, now vitamin A are both found in Cod liver oil and other fish liver oils.
The following biological functions of vitamin A may be listed;
1) It is specific in the prevention and cure of xerophthalmia and nyctalopia.
2) It prevents hyperkeratosis of the skin which may occur in several cases of vitamin
A deficiency.
3) It is useful in overcoming retardation of growth and development when this is
due to vitamin A deficiency.
4) It is of value for increasing resistance of the body to infection only when there has
been an inadequate injection of vitamin A.
56
VITAMIN B COMPLEX
The vitamin B complex includes a number of dietary essentials which are found in
significant quantities in liver and yeast.
Thiamine/Vitamin B1: Occurs as small, crystalline powder, decomposing at 248; in
a dry form, it is relatively stable to heat and light, in aqueous solution the pH is about 3.1
and such solution may be sterilized by heating for 20 minutes at 120 or for 1 hour at
100, without applicable loss of potency.
Daily requirement: adults 1.2 to 2mg, infants 0.4 to 0.8mg, children 1 to 1.8mg.
Sources: Enriched cereals, whole grain crenels, milk, legumes, and meats. Special sources
include yeast, liver concentrates and synthetic thiamine.
Riboflavin/Vitamin B2: was first identified in milk, and because of its yellow color is
known as lactochrome and later as lactoflavin.
It occurs naturally in the free form or in various chemical complexes with protein,
phosphoric acid, adenine or nucleic acid. Riboflavin is slightly soluble in water and in
alcohol; and is insoluble in lipoidal solvents.
Daily requirement: adults 1.6 to 3mg, infants 0.6 to 1.8mg, children 1.8 to 2mg. The
therapeutic dose is 3 to 5mg.
Sources: Milk, egg yolk, liver, meats, green leafy vegetables and bread.
57
Daily requirement: adults 12 to 20mg, infants 6 to 12mg, children 4mg. The maximum
therapeutic dose is 500mg/day.
Sources: Meats, liver, eggs, milk and nuts. In addition, it has been found that four cups of
strong coffee provides an adequate daily intake.
PANTOTHENIC ACID
It is the designation for the factor in the vitamin B complex necessary for the proper
growth of animals. It is also known as the chick antidermatitis factor.
It is dextrorotatory and is usually marketed as the calcium salt, dextro calcium
pantothenate.
Daily requirement: The therapeutic dose is 1 to 10mg.
Sources: Liver, kidney, yeast, milk cereals, legumes and nuts.
PYRIDOXINE / VITAMIN B6
Pyridoxine consists of a group in which pyridoxine is one of three members.
58
FOLIC ACID
It is a natural vitamin conjugate found in plant and animal tissues.
This vitamin is one of the compklex group and is related to several growth
factors such as vitamin Bc, L.
is
composed of one molecule of glutamic acid, the others contain several molecules.
Uses and dose: - Folic acid is a B-complex vitamin having hematopoietic properties.
Although its mechanism of action is not definitely established, it plays an essential role in
several metabolic processes.
Usual Dose: - Estimated requirement, 0.5mg daily; therapeutic, oral and Intramuscular,
10mg daily.
59
VITAMIN C
Ascorbic acid or vitamin c is found naturally in several forms- the reduced form (ascorbic
acid), the oxidized form (dehydro ascorbic acid), and as ascorbinogen (the protein
complex).
Ascorbic acid is called the antiscorbutic factor.
Ascorbic acid is an optically active compound, but only the leno-form is biologically
active. It is an odorless, white, crystalline substance which slowly darkens upon exposure
to light.
It melts at 190 to 192 and is soluble in water, alcohol and propylene glycol, glycerin
but insoluble in ether and benzene.
Dry ascorbic acid is fairly stable but aqueous solutions are rapidly decomposed when in
contact with air.
Daily Requirement: - Adults, 75mg; children 30 to 100mg; in fetus 30mg.
Sources: - Fresh fruits, potatoes, green leafy vegetables and sea foods.
VITAMIN K
The coagulation vitamin, occurs naturally in two forms, vitamin K 1 and K2
Vitamine K is said to be necessary for the formation of prothrombin in the liver. A
deficiency in prophrombin results in a prolongation of clotting time.
Dosage: - The therapeutic dose in 1 to 2mg daily.
Sources: - Occurs in green leafy materials such as spinach, kale, etc. in tomatoes and in
vegetable oils.
60
VITAMIN E
These are and tocopherol of which - tocopherol is the most potent.
Vitamin E is referred to as the anti-sterility factor.
All these vitamins are odorless oils, insoluble in water but soluble in alcohol, ether and
other fat solvents.
They are stable to heat in the absence of oxygen stable to strong acids and visible light,
but unstable to ultra violet light, alkalis and oxidation.
The tocophenols are antioxidants, the delta compound being significantly more effective
than any of the others but they are destroyed by rancid fats.
Vitamin E is essential for normal course of pregnancy in rates and also for normal growth
and the prevention of paralysis in rates.
Dosage: - Daily dosage of 15 to 30mg of vitamin E gives orally have used in the
treatment of habitual absorbtion.
Sources: - Wheat germ oil, cotton seed oil, green leafy vegetables, egg yolk and meat.
61
INDIGENOUS DRUGS
Plants available within the boundary of a native land are usually called indigenous plants.
In pharmacognosy by the term indigenous plant those plants (herbs, Serbs & trees)
are indicated which have got medical or poisonous activities on human or animal beings.
In fact, from the very beginning of human civilization, human being has identified the
plants from which they have found medicine, food and other consumable materials.
Gradually they learnt to cultivate, preserve and utilize these plants which they considered
useful to them.
With the development of modern chemistry new dimension have been added
including the chemical composition (active/inactive) of the various indigenous plants.
Modern chemistry have contributed in finding out the structure, modifying the structure
and establishing the structure-activity relationship of natural drugs modified from natural
sources. The natural drugs with modified structure have been synthesized also and
gradually the dependence on drugs shifted from natural source of synthetic.
In this way indigenous plants and modern chemistry have contributed a lot, in
providing better drugs to fight against diseases.
Examples of Indigenous plants/drugs are: Anantamul, Arjuna, Chirata, Kalomegh, Amloki, Ashoka, Bahera, Haritaki, Betel Nut,
Karela, Bel, Garlic, Jam etc.
ANANTAMUL
Botanical Name: Hemidesmus Indicus (L).
Family: Asclepiadaceae.
Synonym: Periploca indica L.
Bang: Anantamul. Eng: Indian Sorsaparilla.
Availability: Dhaka and Mymensingh in salforests.
62
Actions & Uses: Root is valuable alternative, toxic, demulcent, and diaphoretic, diuretic
and blood purifier. It also possesses the sudorific properties. It is employed in nutritional
disorders, syphilis, chronic rheumatism, gravel and other urinary diseases, leucorrhoea
and skin affections.
BAHERA
Botanical Name: Terminalia Belerica Roxb.
Family: Combretaceae.
Bang: Bahera, Boira. Eng: Beleric Myrobalam.
Availability: Dhaka, Chittagong and Mymensingh and Tangail.
Actions & Uses: Fruit is laxative, astringent, used in hepatitis; as hair tonic; in breathing
problems, Fruits are also useful in coughs, hoarseness, eye diseases and scorpion stings.
The inside of the fruit is useful in dysenteric-diarrhoea. The pulp is also used in drops,
piles and leprosy. Half ripe fruit is used as purgative. The oil from fruit is used in
rheumatism. Bark is a mild purgative. Kernel is narcotic.
BASAK
Botanical Name: Adhatoda vasica Nees.
Family: Anchtaceae.
Bang: Baswak. Eng: Malbar Nut.
Availability: Placed in all the district of Bangladesh.
Actions & Uses: The root, bark and leaves are useful in cough, asthma, ague and phthisis.
The plant makes sputum more fluid thereby facilitating its removal and breathing, also
used in bleeding piles.
63
BETAL NUT
Botanical Name: Areca catechu L.
Family: Palmae.
Bang: Supari; Gua Eng: Batalnut, Areca Nut palm, Areca Palm.
Availability: In about all districts.
Actions & Uses: The nut is aphrodisiac anthelmintic, nervintonic and emmenagogue;
useful in uninary disorders.
BEL
Botanical Name: aegle marmelos (L.) bcorr.
Family: Rutaceae.
Bang: Bel. Eng: Wood apple, Bel fruit.
Availability: Cultivated all over Bangladesh.
Actions & Uses: Fruit is astringent, digestive, tonic, stomachic, laxative and is believed to
be an invaluable remedy in obstinate cases of chronic diarrhea and dysentery, where
there is no fever and loss of appetite. It has been used in the treatment of constipation.
Unripe fruit is used in diarrhea, dysentery, and ripe food for constipation.
GARLIC
Botanical Name: Allium sativum L.
Family: Lilliaceae.
Bang: Rasun; Eng: Garlic
Availability: cultivated in most of the district in Bangladesh.
Actions & Uses: Bulbs are stimulant, febrifuge, hypoglycaemic, tonic, diuretic,
carminative, aphrodisiac, expectorant, anterheumatic, anthelmintic, alterative; used in
fevers, coughs, piles, indigestion, heart diseases, intestinal diseases, useful in gas
formation, painful menstruation and pain in abdomen and in ears. Juice is useful in hair
tonic, in asthma, whooping cough, headache, leprosy. Garlic lowers the blood
cholesterol level and lowers blood pressure. It is antiseptic and used in wounds. Oil is
stimulant and now largely used as capsule in different ailments.
64
ii. Conjugated.
iii. Derived.
The simple protein hydrolyzes entirely into amino acids; the conjugated proteins are
combinations of a protein and a non-protein group latter being called the prosthetic
group; and the derived proteins are degradation products of the proteins.
EX: Gelatin, Sodium heparin, Glucagon, plant proteins and toxalbumins.
RESINS
Resins are amorphous products of a complex chemical nature.
They are usually formed in schizogenous or in schizolysigenous ducts or cavities and are
end products of metabolism.
Pharmaceutically, they are usually hard, transparent, or translucent and upon heating
soften. Chemically they are complex mixtures of are resin acids, resin alcohols,
resinotannols, esters and resenes.
They are insoluble in water.
Pharmaceutical Resins are obtained: (1) By extracting the drug with alcohol.
(2) By separating from oleoresin by distillation.
(3) By heating the plant part.
(4) By collecting the natural product.
(5) By collecting fossil resins, rosin, podophyllum, colocynth, eriodietyon, jalap,
ipomea, mastic, cannabis.
65
TANNIS
Tannins comprise a large group of complex substances that are widely distribute in the
plant kingdom; almost every family of plants embodies species which contain tannins.
When tannins occur in appreciable quantities, they are usually localized in specific plant
parts such as leaves, fruits, barks, or stems.
Although often found in immature fruits, tannins usually disappear during the ripening
process.
Fruit employs the energy supplied by the oxidation of these tannins in its metabolic
processes, also that the tannins are the source of fruit acids.
Tannins are antiseptic in action; they prevent damage by insects and fungi.
Tannins are non-crystallizable chemicals which with water from colloidal solutions
possessing an acid reaction and a sharp puckering taste. They cause precipitation of
solutions of gelatin as well as of alkaloids, they form dark blue or greenish black soluble
compounds with ferric salts, they produce a deep red color with potassium ferrieyaride
and ammonia, and they are precipitated by salts of copper, lead and lin, also by strong
aqueous potassium dichromate (or 1% chronic acid) solutions. In alkaline solutions many
of their derivatives readily absorb oxygen.
Chemically tannins are complex substances; they usually occur as mixtures of polyphenols
that are very difficult to separate since they do not crystallize.
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Although some tannin may appear to be glycoside in nature, the majority probably are
not. When hydrolyzed, they yield relatively simple polyhydric phenols
(1) Gallic acid, which is broken down to pyrogallol
(2) Protocatechuic acid broken down catechol.
(3) Ellagic acid etc.
The phenolic groups of the tannins are responsible for their astringent and antiseptic
actions as well as their coloration with iron salts.
The classification of tannins is based upon the colors obtained with iron salts,
The presence of catechol with its two adjacent phenolic groups, a green color is obtained
with ferric iron, and in the presence of pyrogallol with its three adjacent phenolic groups,
a blue color is obtained.
Classification of Tannins: Catechol (pyrocatechol) Tannins or phlobatan nins show the following characteristics : a) When heated: They yield catechol.
b) When boiled with HCl: They yield insoluble, red phlobaphenes.
c) They form a: green color with FeC3 T.S.
d) They form a: Precipitate with bromine T.S.
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PYROGALLOL TANNIS
Pyrogallol Tannins show these characteristics: a) When heated: They yield pyrogallol.
b) When boiled: with HCl They yield gallic acid or ellagic acid.
c) They foem a blue color with FeCl3 T.S.
d) They do not form a pre3cipitate with bromine T.S.
Pyrogallol tannins are gallol tannins in Nutgall and ellagetannin in oak bark and
pomegranat bark
LIPIDS
LIPIDS
Lipids are esters of long chain fatty acids and alcohols, or closely related derivatives.
The chief difference between these substances is the type of alcohol, in fixed oil and fats.
Glycerol combines with the fatty acids; in waxes, the alcohol has a higher molecular
weight, cetyl alcohol has a higher molecular weight, cetyl alcohol being an example.
Fats and fixed oils are obtained from either plants or animals. Their primary function
is food storage. The fixed oils and fats are important products used pharmaceutically,
industrially and as a food. Waxes may also be of plant or animal origin.
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If R, R, R are the same fatty acid radical, the compound is called twolein, tsipalmitin,
tristearin, etc. as the case may be. If R, R, R are the more different fatty acids, a mixed
glyceride results.
Triolein containing radioactive iodine and referred to as I131 triolein in useful as a
rapid, simple and reproductive method for clinical studies of impairment of absorptive
functions and digestive defects. The route through the human body followed by such
tagged lipids can be traced easily, and determination of blood level I131 can be
correlated with urinary I131 excretion and with fecal I131 excretion.
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Biosynthesis of lipids
The synthesis of fats include the hydrolysis of the glycerol, fatty acids esters by the
enzyme lipase and the subsequent removal of 2 carbon units as acetyl coA from the
fatty acid chain by oxidation.
Biosynthetic studies indicate that the formation of these lipids different chemical
pathways. Considering first the biosynthesis of the fatty acid moieties, It has been shown
that these are produce by a series of reactions involving two enzyme complexes plus
ATB, TPNH, Mn+ + , and CO2
Acetate first secrete with CoA and acetyl-CoA. Thus form is converted by reaction
with CO2 to malonyl-CoA. This is turn reacts with an additional molecule of acetyl CoA
to form a 5carbon intermediate which undergoes reaction and elimination of CO 2 to
produce butyryl CoA. Malonyl-CoA again reacts with its compound to form a 7-carbon
intermediate which is reduced to capronyl CoA.
Repetition of the reaction results in a fatty acid containing as even number of carbon
atoms in its chain. Thus manonyl-CoA, a 3-carbon compound is actually the source of the
2-carbon biosynthetic units of the fatty acids.
Pathways of biosynthesis of unsaturated branched chain, odd numbered and other
wised modified fatty acids have not been established in detail.
There is evidence that the first step in the production of monounsaturated acid is the
formation of the acetyl CoA derivative of its saturated analogue.
This is followed by enzymatic desaturation, additional reductions may then ensure
CASTOR OIL
COCONUT
LANOLIN
LINSEED OIL
OIL
AHHYDROUS
CLIVE OIL
PERSIC OIL
LANOLIN
CORN OIL
CHLESTEROL
SWEET
LARD
SITOSTEROLS
ALMOND OIL
STEARIC ACID
SPERMACETI
OLEIC ACID
BEESWAX
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Pharmacognosy & Ph
Md. Asif