pharmacognosy

1. By:
Dr. Marwa Fayed
(Ph.D)

2. Unorganized drugs may be classified under headings
based upon their origin and nature, giving well
characterized groups, such as:
I- Resin and resin combinations.
II- Gums.
III- Dried latices.
IV- Dried juices.
V- Dried extracts.
VI- Saccharine substances.
VII- Oils and Fats.

3. Ex.:
- Jalap
- Podophyllum
Ex.:
- Filicis
- Copaiba
Ex.:
-Asafoetida
- Galbanum
- Myrrh
Ex.:
- Benzoin
- Peru balsam
- Tolu balsam
Ex.:
- Gamboge
Ex.:
- Turpentine
- Guaiacum
- Mastic

4. Resins
• General characters:
• Hard, solid or semi-solid, amorphous organic
substances of complex chemical nature.
• Insoluble in: water and petroleum ether.
• Soluble in: alcohol, chloroform, ether and in many
of the organic solvents as well as in fixed and
volatile oils.
• They are brittle secretions or exudations of plant
tissues, produced either normally or due to
pathogenic conditions.

5. Preparation of resins
I- Natural resins: are those collected from the plants.
II- Prepared resins: (or resin combinations), these
are obtained by one of the following methods:
1- Extracting the plant containing a resin with
alcohol then the solvent is either evaporated or
the solution poured in water to precipitate the
resin.
2- Extracting the plant containing oleo-resin with
ether or acetone followed by distillation to
remove the oil.
3- Extracting the plant containing gum resin with
alcohol in which the gum is insoluble.

6. Chemical Composition of Resin
1- Resin acids:
• These are diterpenoid oxyacids, usually combining the properties of
carboxylic acids and phenols.
• Their metallic salts are known as resinates.
• Examples are abietic acid in Colophony and commiphoric acid in
Myrrh.
2- Resin alcohols:
• These are complex alcohols of high molecular weight.
• They are subclassified into resinotannols and resinols.
• Resinotannols give a tannin reaction with ferric chloride e.g.
Siaresinotannol and sumaresinotannol (Benzoin).
• Resinols give no color reaction with ferric chloride e.g. benzoresinol
from benzoin and ammoresinol from ammoniacum.

7. 3- Resenes:
• These are complex neutral oxygenated substances
devoid of characteristic chemical properties.
• They do not form salts or esters.
• They resist hydrolysis with alkalis.
• They resist the action of oxidizing agents.
• They generally used in the manufacture of varnishes.
4- Glycosidal mixtures:
• These are complex mixtures yielding on hydrolysis
sugars and complex resin acids as aglycones.
• Ex. Jalapin from Jalap resin.

8. Turpentine
Colophony, Rosin
Botanical Origin:
Colophony is the residue left
after distilling the volatile oil
from the oleo-resin obtained
from Pinus species especially
Pinus palustris , Family:
Pinaceae.

9. Transverse section through the wood of Pinus species
showing an oleo-resin duct

10. Collection and Preparation
Cup and Gutter method

11. Cup and Gutter Method
During spring the bark is chipped from the tree with a long- handled cutting
blade. 50% sulphuric acid is sprayed on the freshly cut surface. This
treatment collapses the thin-walled parenchyma cells that line the resin
ducts, allowing the duct channels to become larger. This results in a more
rapid flow of the oleo-resin (crude turpentine) and reduces the chances of
hardened secretions blocking the outlets. The flowing oleo-resin is guided
by metal gutters into containers attached directly to the trunk. The crude
turpentine removed periodically and taken to the turpentine still, which
are of copper, and are set in brick furnaces. Water is added and the whole
warmed, any chips of wood, and other debris, that float to the top being
skimmed off the heat is then increased. At first, water and oil of
turpentine distill over, subsequently oil of turpentine alone. Water is
occasionally added to prevent the resin from charring. After the distillation
has been stopped the melted resin is run through wire strainers into
barrels and allowed to solidify.

12. • Description:
- pale amber-coloured, transparent, glassy masses, very brittle
and easily powdered.
- a faint terebinthinate odour and taste.
- burns with a dense yellow smoke.
• Solubility:
- Insoluble in water.
- Soluble in: alcohol, chloroform, ether, benzene, carbon
disulphide, glacial acetic acid, fixed and volatile oil, dilute
solutions of potassium & sodium hydroxide.
- Partially soluble in: petroleum ether.

13. Active Constituents
1- Resin acids: 80-90% of diterpene acids (Abietic acid)
2- Esters of fatty acids.
3- Resene: represented by a small proportion of hydrocarbons.
Therapeutic Uses
In pharmaceutical industries:
Colophony is used as ingredient in plasters and ointments.
Commercially:
- used in the manufacture of varnishes, paint dryers, printing inks,
soap, sealing wax, floor coverings.

14. Special Chemical Tests
1- Copper acetate test (for abietic acid)
Extract the powder with petroleum ether and filter,
Shake the filtrate with Cu acetate.
The petroleum ether layer turns bluish-green due
to the formation of the copper salt of abietic acid.
2- 1% soln. of Colophony + 5ml pet.ether + 1 drop
H2SO4 bright purplish-red color
which rapidly changes.

15. Turpentine oil
- consists mainly of α-pinene (64%) and β-pinene
(33%) and some minor constituents.
Uses
- mild antiseptic action,
- insecticide,
- solvent for waxes,
- production of synthetic camphor,
- furniture polishes.

16. Rectified turpentine
• It is obtained by distillation of turpentine oil
from an aqueous solution of NaOH.
• It is used as stimulant to the mucous
membrane, diuretic and expectorant.

17. Guaiacum Resin ‫األنبياء‬ ‫خشب‬ ‫راتنج‬
• Botanical origin:
• Guaiacum resin is
obtained from the heart
wood of Guaiacum
officinale and Guaiacum
sanctum, Family:
Zygophyllaceae.

18. Preparation of the resin
• Guaiacum wood chips are boiled in salt solution,
when the resin which melts at about 85°C may be
more or less separated from the wood.
Description
-in large blocks or rounded tears about 2-3 cm in diameter, often
covered with a dull green powder.
- Color: powder is grayish but become green on exposure to light
and air,
-Taste: slightly acrid,
- Odor: aromatic especially when warmed.
- Solubility: soluble in ether, chloroform, alcohol, solutions of
caustic alkalies and in chloral hydrate.

19. Active constituents
• Some of the main resinous constituents belong to
the group of Lignans. These are phenolic
compounds having a C-18 structure formed from
C6-C3 units.
• Guaiaretic acid, which forms about (10%) of
guaiacum resin, is a diaryl butane.
• The resin contains about (70%) α- and β-
guaiaconic acid and guaiacic acid.
• α - guaiaconic acid is the substance which yields
the blue compound guaiac- blue when guaiacum
resin is acted upon by oxidizing agents.

20. Test for identity
- Dissolve about 0.05 gm of freshly powdered resin
in 5 ml of alcohol and add 1ml. of a solution of
FeCl3 in water. A deep blue color is produced.
Therapeutic Uses
- For use as a reagent the resin extracted from wood
by means of chloroform is said to be the most
sensitive. An alcoholic solution is used for the
detection of blood stains, cyanogenetic
glycosides, oxidase and peroxidase enzymes.

21. Mastic Resin ‫المســــــتكة‬
• Botanical Origin:
Mastic is a resin, containing
little oil, obtained from
cultivated variety of
Pistacia lentiscus Var.
chia, Family:
Anacardiaceae

23. Collection and preparation
• The base of the shrub is cleared of weed.
Flatten and covered with a special white soil to
receive some of the flow. The stem and larger
branches are then wounded by means of
special knife which makes an incision about
2cm long and 3mm deep. Each plant is tapped
repeatedly for about 5 or 6 weeks receiving in
all about 200-300 wounds. A special tool is used
for the removing the tears which harden on the
plant and the flat plates of mastic which
collected on the ground .

24. Description:
• Color: yellow or greenish – yellow rounded or
pear-shaped tears about 3 mm in diameter.
- The tears are brittle but becomes plastic when
chewed.
- Odor: slightly balsamic,
- Taste: mildly terebinthinate.
Active Constituents
- Mastic is an acid resin and contains triterpenoid
acids such as masticadienonic acid and triterpene
alcohols, about 2% of volatile oil is also present.

25. Therapeutic Uses
- Mastic is used for stomach and intestinal ulcers, breathing
problems, muscle aches, and bacterial and fungal infections.
It is also used to improve blood circulation.
- Some people apply mastic directly to the skin for cuts and
as an insect repellent.
- In dentistry, mastic resin is used as a material for fillings.
- Chewing the resin releases substances that freshen the
breath and tighten the gums.
- In manufacturing, mastic resin is used in the food and drink
industries and in the production of chewing gum.

26. B-Oleo-resin
1- Male fern oleo-resin, Oleoresina Filicis
Malis
• Male Fern oleo-resin may be prepared by
extraction the powder rhizome, formed bases and
apical buds of Dryopteris filix-mas, Family:
Polypodiaceae , with ether. The ethereal extract is
evaporated on a water bath until an oleo-resinous
extract remains.

27. • Description:
- a thick dark green liquid, frequently depositing a granular
crystalline substance,
- an agreeable odor,
- bitter astringent taste.
• Solubility:
- insoluble in water,
- soluble in ether,
- not less than 85% of it is soluble in light petroleum ether.

28. • Active constituents:
The active constituent of male Fern are phloroglucinol derivatives
which occur as mono-, di-, tri-, and tetra-cyclic compounds.
These constituents are acid in nature and termed Filmarone and
to which the Taenicide activity of the drug is due to Filicic,
aspidinol, flavaspidic acid, flavaspidinol are also contained in it.
- Filmarone occurs as a bright yellowish-brown powder insoluble
in water, soluble, in organic solvent, and alkali hydroxides and
carbonate. It is slowly hydrolysed in the drug or in solution:
Filmarone ® Filicic acid + Aspidinol
Filicin
Filicic acid is therapeutically inert and upon heating , it is
converted to its lactone filicin.

29. Test for identification
 Mix about 0.1 gm of male Fern oleo-resin and
0.2 gm of talc.
 Shake vigorously with 10 ml of hot alcohol then
filter.
 Add to 1ml of the filtrate 9 ml of alcohol and 1
drop of FeCl3
 solution a light green color is produced which
changes to brown.
Therapeutic Uses
Male Fern oleoresin is used as taenicide.

30. 2- Copaiba, Oleoresina Copaiba
• Botanical origin:
Copaiba is an oleo-resin obtained
by incision from the trunks of
Copaifera langsdorfii, Family:
Leguminosae.
- Copaiba is sometimes
commercially wrongly known
as Copaiba balsam .

31. • Description:
- Copaiba is a pale yellow, or golden brown,
- more or less viscous liquid, more or less transparent
with occasional slight greenish fluorescence.
- characteristic aromatic odor,
- bitter, acrid and persistent taste.
• Solubility:
- insoluble in water,
- partially soluble in alcohol, chloroform, ether,
benzene, acetone, carbon disulphide and in fixed
and volatile oils.

32. Active Constituents
• Copaiba contains at least 24 sesquiterpene
hydrocarbons, resin acids e.g., capaivic acid,
small quantity of a bitter principle and a
fluorescent substance.
Therapeutic Uses
- in inflammatory affections of bladder, urethra and
occasionally in chronic bronchitis

33. C- Oleo-Gum Resin
1- Asafoetida, Gummiresina Asafoetida
• Botanical origin:
• Asafoetida is an oleo-gum-
resin obtained by incision
from the living rhizome and
root of Ferula feotida,
Family Umbelliferae.
• The drug is collected in Iran
and Afghanistan.

34. Collection and preparation:
This involves the removal of the stem and cutting of successive slices from
the vertical rootstock. After each slice is removed oleo-gum-resin
exudes and when sufficiently hardened is collected and packed in tin-
lined cases.
Description:
- occurs in rounded or flattened tears, from 1.2 to 2.5 cm in diameter, or
as masses of these tears formed by agglomeration.
- grayish – white to dull yellow.
- freshly exposed surface is yellow and translucent or milk-white and
opaque, gradually passes through a very characteristics change of color
on exposure to the air or light, and finally reddish brown,
- strong and alliaceous persistent odor,
- bitter alliaceous and acrid taste.

35. Active Constituents
- Volatile oil (10-16%), Resin (40-60%), Gum (20-30 %) and impurities.
- The volatile oil consisting principally of organic sulfides and pinenes.
- The resin consisting of asaresinotannol free and partly combined with
ferulic acid.
- There is also some free ferulic acid.
- The drug contains no free umbelliferone. On boiling it, however with
hydrochloric acid and filtering into ammonia a blue fluorescence is
produced owing to the formation of umbelliferone. Ferulic acid is closely
related to umbellic acid and umbelliferone.

36. Therapeutic Uses
Asafoetida is now little used in human medicine
(as a carminative, expectorant and
antispasmodic) although still employed in
certain food spices.

37. Tests for identity
1- Place a drop of H2SO4 on the freshly fractured
surface of a tear, a bright red or reddish-brown
color is produced changing to violet when the acid
is washed off with water.
2- Boil 0.5 gm of coarsely powdered drug for few
minutes with 5 ml HCL mixed with 5 ml of water.
Filter, cool and add to the filtrate an equal volume
of alcohol and excess of ammonia, a blue
fluorescence is produced.

38. 2- Myrrh, Gummiresina Myrrha
• Botanical origin:
Myrrh is an oleo-gum-resin obtained from the stems and
branches of Commiphora molmol, Family Burseraceae.

39. • Description
- Myrrh occurs in tears, rounded or irregular or in
masses of tears varying much in size and shape.
- The surface is usually covered with a fine
yellowish-brown powder.
- Beneath this the color is reddish-brown or
reddish-yellow.
- The fracture is brittle and uneven.

40. Active constituents
- Volatile oil (7-17 %), Resin (25-40 % ), Gum (57-61
%) and 3-4 % of impurities.
- The volatile oil contains terpenes, sesquiterpenes,
esters, cuminic aldehyde and eugenol.
- The gum present in the drug is similar to acacia
gum and contain also an oxidase enzyme.

41. Test for identity
Triturate about 0.5 gm of myrrh with 1 gm of sand and
shake with 10 ml of ether. Filter, divide the filtrate
into two portions and evaporate in a porcelain dish.
- To the film left in one porcelain dish, add few drops
of HNO3; a purplish-violet color is produced.
- Over the film left in the other porcelain dish pass the
vapour of bromine, where a violet color is
produced.
Therapeutic Uses
Myrrh has stimulant and antiseptic properties, it used
as a mouthwash and us uterine stimulant and
emmenagogue, flavoring agent.

42. D – Balsams
1- Benzoin ‫الجاوى‬
• Botanical origin:
- Benzoin is a balsamic resin obtained
from the incised stem of Styrax
benzoin known in commerce as
Sumatra benzoin or Styrax tonkinensis,
known in commerce as Siam benzoin,
Family: Styraceae.
- The trees from which benzoin is
obtained do not contain any special
secreting cells or ducts and normally
produce no benzoin, the formation of
which is induced by injury to the tree.

43. Description
Sumatra benzoin occurs in masses consisting of opaque creamy white tears embedded in a
dull grayish-brown or sometimes reddish-brown matrix. It is in hard and brittle and the
fractured surface is dull and uneven. It possesses an agreeable balsamic odor and
slightly acrid taste, when gradually heated it melts and evolves whitish irritating fumes
of benzoic and cinnamic acids, when a little of the crushed resin is warmed with dilute
sulphuric acid and potassium permanganate, benzaldehyde is evolved indication the
presence of cinnamic acid in the drug.
Siam benzoin occurs in tears or in blocks the tears are of variable size they are yellowish
brown or reddish brown or reddish brown externally but milky white and opaque
internally, the block form consists of small tears embedded in a somewhat glassy,
reddish-brown, resinous matrix. It has vanillin like odour and balsamic taste.

44. Active constituents
Sumatra benzoin contains free balsamic acid (cinnamic and benzoic acid)
and esters derived form them also present are triterpenoid acids. The
content of total balsamic acids is at least 25% and the amount of
cinnamic acid is usually double that of benzoic acid. Up to 20% of free
acids may be present the drug contains, in addition traces of
benzaldehyde, vanillin, phenyl propyl cinnamate, styrol and styracin.
Siam benzoin consist chiefly of coniferyl benzoate, other constituents are
free benzoic acid, triterpenoid acids and Vanillin.

45. Test for Identity
1- when about 0.5 gm of powdered benzoin is warmed with
10ml of potassium permanganate solution, a faint odor
of benzaldehyde is developed only with Sumatra benzoin
but not with the Siam benzoin.
2- Digest about 0.2 gm of the coarsely powdered benzoin
with 5ml of ether for about 5 minutes decant about 1ml
of the ethereal solution into a porcelain dish containing 2-
3 drops of H2SO4 and mix carefully, a deep purplish – red
color with siam benzoin and deep reddish brown color in
produced with Sumatra benzoin.
Therapeutic Uses
Benzoin when taken internally acts as an expectorant and
antiseptic, externally it is stimulant and antiseptic.

46. 2- Balsam of Tolu ‫الطولو‬ ‫بلسم‬
Balsamum tolutanum
• Botanical origin:
• Balsam of tolu is balsam
obtained by making
incisions in trunk of
Myroxylon balsamum,
Family Leguminosae.

47. Description:
Balsam of Tolu when freshly imported is a soft
yellowish - brown semi-solid, resinous mass
which takes the form of the vessel in which it is
kept, on keeping it gradually hardens to brownish
and especially in cold weather brittle and easily
powdered, readily soften when warmed, it has
an agreeable fragrant odor which is not powerful
and an acidulous balsamic taste and adhere to
the teeth when chewed. It is easily soluble in
alcohol, acetone, and chloroform.

48. Active constituents
- Tolu balsam contains about 7.5 % of an oily liquid
consisting of benzyl benzoate with little benzyl
cinnamate, traces of vanillin, free aromatic acids,
principally cinnamic (12-15%) and benzoic acid
(8%).
- The resin forming about 80% of the drug, yields
by saponification the alcohol tolu resinotannol,
cinnamic acid and little benzoic acids.

49. Test for identity
1- A solution of balsam tolu im alcohol is acid to litmus
paper.
2- To an alcoholic solution of the balsam (5%) add a few
drops of ferric chloride a green color produced.
3- Boil 1gm of balsam of tolu with 5ml of water filter
add to the filtrate 3ml of potassium permanganate
and warm the odor of benzaldehyde is developed.
Therapeutic Uses
Tolu balsam in used chiefly as a pleasant ingredient in
cough mixtures it possesses antiseptic properties due
to cinnamic and benzoic contained in it .

50. 3-Balsam of Peru, Balsamum
peruvianum ‫بـيـرو‬ ‫بلسـم‬
• Botanical origin:
• Balsam of Peru is a balsam
exuded from the trunk of
Myroxylon pereirae, Family
Leguminosae, after the
trunk has been beaten and
scorched.

51. Description
Balsam of Peru is a rather viscid oily liquid, free from
stickiness and stringiness.
It appears black in bulk, but in thin layers it is dark reddish –
brown and transparent. It has a fragrant balsamic odour,
somewhat vanilla – like odor and acrid slightly bitter taste.
The drug is almost insoluble in water. It is soluble in equal
volume of alcohol. The specific gravity, 1.1470-1.170 is a
good indication of purity.

52. Active constituents
Balsam of peru consists mainly of an oily fluid portion
mixed with dark resin. The fluid potion (cinnamein)
constitutes from 56-90% of the drug and consists of
benzylbenzoate and benzyl cinnamate. It also
contains about 28% of resin consisting of
peruresinotannol combined with cinnamic and
benzoic acids, small quantities of vanillin and free
cinnamic acid.
Test For Identity
Shake about 0.5 gm of balsam Peru with 10 ml of
water, the aqueous solution is acid to litmus.
Therapeutic Uses
Balsam of Peru is used internally as an antiseptic and
expectorant; applied externally it acts as an
antiseptic and parasiticide, especially for scabies.

53. Plant gums ‫الصموغ‬
- Gums are abnormal products exuded from
certain plants as pathological products in
response to injury or unfavorable conditions,
e.g. Gum arabic and Gum tragacanth.

54. Wounding of
branches and gum
exudate

55. Gum Arabic (Gum Acacia)
• It is the dried gummy
exudate obtained by
incision from stems and
branches of Acacia
senegal, Family:
Leguminoseae

56. • Properties:
- occurs as translucent spherical tears or angular
fragments.
- water-soluble, insoluble in ethanol and ether..
- + lead acetate no precipitate.
- + basic lead acetate a flocculent ppt.
- + Iodine no color.
- + tincture guaiacum or benzidine a blue color
(due to the presence of oxidase enzymes).

57. • Constituents:
1- Arabin: a complex mixture of calcium,
magnesium and potassium salts of Arabic
acid.
Arabic acid: branched polysaccharide with the
basic building unit is galactose.
2- enzymes: oxidases, peroxidases and
pectinases.
• Uses:
1- Emulsifying and suspending agent.
2- demulcent and emollient.
3- adhesive and binder in tablet manufacture.

58. b- Gum Tragacanth
Origin:
• the air hardened gummy
exudates obtained by
incision from Astragalus
gummifer and other
Asiatic species of
Astragalus, Family:
Leguminosae

59. • Solubility:
• slightly soluble in water, swelling at first into a
homogeneous adhesive mass. It is insoluble in
ethanol.
• Constituents:
1- Bassorin: a complex of polyhydroxylated acids
2- Tragacanthin: demethoxylated bassorin

60. • Chemical tests:
1- aqueous solution + HCl, heat for 30 min., divide into two
portions:
a- add NaOH and potassium copper tartarate, heat in W.B. → red
ppt
b- add BaCl2 → no ppt (agar).
2- solution in water + barium hydroxide → slight flocculent ppt ,
heat → yellow colour.
• Uses:
As gum arabic, but due to its resistance to acid hydrolysis it is
preferred for use in highly acidic conditions.

61. MUCILAGE
- are generally normal
products of metabolism
formed within the cell
(intracellular formation).
Function of Mucilage:
- Storage material.
- Water storage reservoir.
- Protection for germinating
seeds.

62. • Properties:
- white amorphous masses.
- swell in water and form viscous non-adhesive
solutions.
- have variable physical and chemical properties.
• Classification:
- The neutral mucilages.
- The acidic mucilages.
- The sea weed mucilages.

63. Dried latex
Latex is an emulsion or suspension, the continuous
phase of which is an aqueous solution of mineral
salts, proteins sugars tannins, alkaloids, etc., and
the suspended particles are oil droplets, resin,
gum, proteins, starch, caoutchouc. This turbid
fluid is often white in color, as in opium (Papaver
somniferum), but may be yellow as in Argemone
mexicana or red as in the rhizome of Sanguinaria
Canadensis. Latex occurs in the plant in special
structures named laticiferous cells, tubes or
vessels, from which it is obtained by incision into
the plant.

64. Opium ‫األفـيـون‬
• Botanical origin:
Opium is the air dried latex
obtained by incision from the
fully grown but unripe capsule
of Papaver somniferum, family:
Papaveraceae.

65. Capsules of Papver somniferum showing incisions for
the production of Opium

66. Collection and preparation
While the capsules are still green or just showing a tint of yellow,
incision are made in the walls, so as not to penetrate into the
locules, which would result in loss of opium and also prevent the
seeds from ripening . Precaution must be taken to chose the time
for making the incisions so that neither rain, wind nor dew is likely
to spoil the exudation. The incision cuts across the laticiferous
vessels and, since these vessels ramify and anastomose throughout
the phloem tissues of the capsule wall, the latex from a large area
of the capsule exudes in small drops along the edges of the
incisions and partially dries in air. The incisions are usually made in
the afternoon and the exuded latex in scraped off with a knife or
special instrument early in the following morning. The collected
exudate is mixed and dried and packed.

67. Description
Opium occurr in more or less rounded or cubical
pieces or some what flattened or brick – shaped
masses usually about 8- 10cm in diameter, varying
in weight but commonly weighing between 250-
1000 gm, sometimes wrapped in tissue paper,
cellophane or covered with poppy leaves;
externally dark brown to chocolate brown; more
or less elastic when fresh, becoming hard and
tough, or occasionally brittle on keeping, internally
dark brown, coarsely granular or nearly smooth.
Opium has strong characteristic narcotic odour
and characteristic very bitter taste.

68. Constituents
Opium contains about 30 different alkaloids, belonging to different
chemical groups which occur in combination with MECONIC acid.
Other constituents are small amount of mucilage, sugars, wax and
salts of calcium and magnesium.
The most important alkaloids are morphine (10-20), codeine (methyl
morphine 0.3-0.4%), narcotine (2-8%), thebaine ( 0.2-0.5%)
narceine, and the remaining alkaloids are present in very small
quantities constituting together rather more than 1% of thedrug.
Test For Identity
Warm about 20-30mg of powdered opium in 2-3 ml of water for few
minutes and then filter. On adding a few drops of 5% ferric chloride
solution to the filterate, a purplish red color is produced and the
color is not destroyed by the addition of dilute hydrochloric acid or
5% mercuric chloride solution (Test For Meconic Acid)

69. Dried Juice
ALOE ‫الصبر‬
• Botanical Origin:
Aloes is the solid residue
obtained by evaporating
the juice which drains
from the cut leaves of
Aloe vera family:
Liliaceae.

70. Preparation Of Aloes
• The leaves are cut transversely
near the base and about 200 of
them are arranged around a
shallow hole in the ground
which is lined with a piece of
canvas or a goatskin. The leaves
are arranged as that the cut
ends overlap and drain freely
into the canvas. After about 6
hours all the juice has been
collected and it is transferred to
a drum in which it is boiled for
about 4 hours on an open fire,
the product is poured whilst
hot into tins, where it solidifies.

71. Constituents
1- Anthraquinones e.g. Aloin, barbaloin,
isobarbaloin, emodin and chrysophanoic acid.
2 Saccharides e.g. cellulose, glucose, mannose
and L-rhamnose.
3- Enzymes e.g. oxidase, amylase and lipase
4- Vitamins e.g. B1, B2, B6, C, E, folic acid and β-
carotene
5- Minerals e.g. calcium, sodium, manganese,
magnesium, zinc and cupper.

72. Uses
1- Topical: Wound healing, sunburn, hair tonic and minor skin irritation.
2- Oral: Constipation and peptic ulcers.
Test for identity
1- Borax test Boil about 0.5g of powdered aloe with 50ml of water for 2-3 m.
Clarify with kiesselguhr and filter. Add 0.2 g of borax to 5ml of filtrate and
heat. Pour 2-3 drops of the dark fluid into water where a green fluorescence
is produced.
2- Modified Borntrager’s test
Mix 0.1g of powder with 5ml of 5%FeCl3 and 5ml dil. HCl. Heat for 5minutes in
boiling water bath and cool. Shake with benzene and separate the benzene
layer and add NH4OH pink to red colour is formed in the ammonical
layer.

73. Dried Extracts
This group includes drugs prepared by evaporating
aqueous decoction of whole or parts of certain
plants or animals.
1- Gelatin
It is the protein obtained by boiling the collagenous
tissues of animals such as skin, tendons, ligaments
and bones with water, evaporating the aqueous
extract and drying the residue in air.

74. Description
Gelatin occurs in thin sheets or in shreds, or
powder which may be nearly colorless. It is hard
and brittle; when broken it at first bends and
then breakes suddenly with a short fracture .
- In cold water it swells and when heated dissolves
- it is soluble in acetic acid and glycerol, but not in
alcohol and ether.
- A 2 % hot a queous solution should gelatinse on
cooling.

75. Active Constituents:
It is formed mainly of protein and glutin.
Uses:
1- Nutrient and bases for glycerin suppositories.
2- Preparation of nutrient medium for bacterial growth.
Tests for identity:
1- On heating with soda lime, ammonia odour is
evolved.
2- 2% hot aqueous solution gelatinize on cooling
3- The aqueous solution gives a precipitate with solution
of tannic acid and lead subacetate.
4- Millon’s reagent it gives a white precipitate which
becomes red on boiling .

76. 2- Agar-Agar ‫آجار‬ ‫آجار‬
- Agar is the bleached and dried product
obtained by concentrating a decoction made
from various species of algae belonging to the
class Rhodophyceae.
- Agar from Japan is made chiefly from species
of Gelidium, especially G. elegans and G.
amansil, Family: Gelidiaceae.

77. Preparation
In Japan the seaweeds are collected by removing them
from the ocean floor. They are then spread upon beach
to dry. The dried seaweeds are beaten and shaken to
remove shells, sand etc. weed is washed water,
bleached by exposure to the sun and then boiled in
open boilers for 5-6 hours with about 50 times its
weight of very faintly acidulated water. The liquor is
strained through cloth and transferred to wooden
troughs (100 x 40 x 8 cm ) where it is allowed to cool in
the open air and the liquid congeals. The jelly is cut into
pieces about 5 x 8 x 40 cm, using knifes guided by a
ruler. These rectangular pieces of jelly is then forced
through a netting and the narrow strips thus formed are
spread out to dry and bleaching in the air and sunshine.

78. Constituents:
- Agar is composed chiefly of a calcium salt of a
sulphuric acid ester of a carbohydrate complex.
- When hydrolysed by boiling with dilute
hydrochloric acid it yields galactose and
sulphuric acid.
- Agar contains a small traces of proteins .

79. Chemical tests:
1. Boil 1 gm of agar for 10 minutes with 100 ml
of water, the solution yields a stiff jelly on
cooling.
2. Powder + I2 → reddish to violet but not blue
colour.
3. powder + rhuthenium red → the particles are
stained deep red.
4. Aqueous solution + dil. HCL, boil in W.B. for 30
min, add BaCl2 → white ppt.

80. Uses:
- Agar-agar is largely used for the preparation of
bacteriological culture media.
- Agar passes through the intestinal canal
unchanged, but absorbs water during its passage
and thus promotes peristalsis, for which purpose
it is frequently used for treatment of
constipation .