pharmacognosy lab manual

LABORATORY MANUAL

OF

PHARMACOGNOSY

Experiment-1

Aim-To study the macroscopic characters of datura

References- 1.Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Edition 41,

Reprint 2008, Nirali Parkashan, Page no. 501-502

2. Shah N. B., Nayak B. S., Experimental Pharmacognosy, First Edition April,2008, S.

Vikas Page no. 109-111

THEORY

Synonym- Datura herb

Bio. Source- It consists of the dried leaves and flowering tops of Datura metel Linn.

And other species of Datura belonging to Family Solanaceae

MACROSCOPIC CHARACTERS:

Leaf

Color-Lower surface is slightly pale in color

Upper surface is darker than lower surface.

Size- the entire leaf has a length of 6-13 cm. and width of 8-13 cm.

Shape- ovate and petiolate

Lamina- Glabrous and usually has 3 to 4 coarse teeth

Apex-acute

Base- unequal

Texture- smooth and thin

Midrib- Prominent

Seeds

Color-Brown

Shape-Triangular

Flowers- Reddish purple on outside and whitish on inner side

Shape- Funnel Shaped

Fruits

Color- Green

Shape-Oval with spines

Size- Fruit has length of 4.5 cm and width of 3.5 cm

Odour- Disagreeable and characteristic

Taste- unpleasant bitter

Chemical constituents-

Datura leaf mainly contains tropane alkaloids (upto 0.5%) of which hyoscine is main

alkaloid. L-hyoscyamine and atropine are present in less quantity.

Hyoscine is an ester of tropic acid ad scopine.

Chemical tests:

1. Vitali-morin test-It is specific test for tropane alkaloids. Powdered sample is

moistened with nitric acid followed by evaporation to dryness and addition of

methanolic potassium hydroxide solution to the residue, a violet color is

produced.

2. On addition of silver nitrate solution to the solution of hyosine hydrobromide,

Yellowish white ppt. formed which is insoluble in nitric acid but soluble in

dilute ammonia

Uses-

1. Datura herb and its main alkaloid hyoscine are parasympatholytic with

anticholinergic and central nervous system depressant effects.

2. It is used in cerebral excitement.

3. Along with morphine, it is used as preoperative medication.

4. It is used in treatment of ashma and cough

5. Hyoscine hydrobromide is used in motion sickness, gastric or duodenal ulcers

Cautions:-

Do not taste the crude drug because it might be harmful to the human body in crude

form.

Experiment-2

Aim-To study the macroscopic characters of withania

Reference- 1.Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Reprint 2008,

Nirali Parkashan, Page no. 13.79-13.81.



Theory

Withania

Synonym- Asgandh, Winter cherry, withania root

Bio. Source:- It consists of dried roots and stem bases of Withania somnifera Dunal,

belonging to family Solanaceae


Color- outer surface is Buff to grey-yellow with longitudinal wrinkles

Odour- Fresh roots have smell similar to urine of horse

Taste- Bitter and acrid

Shape- Straight, unbranched, conical and bears a crown.

Fracture- smooth and powdery


Main constituents are alkaloids and steroidal lactones. Among the various

alkaloids, withanine is the main constituent. other alkaloids are somnine,

somniferinine, withananine, pseudo-ithanine, tropine, pseudo-

tropine, cuscohygrine, anferine andanhydrine. Two acyl steryl glucosides, sitoindoside

VII and sitoindoside VIII, have been isolated from root. The leaves contain steroidal

lactones, which are commonly called withanolides. The withanolides have C28 steroidal

nucleus with C9 side chain and a six-membered lactone ring.

Uses-

1. Sedative and Hypnotic

2. adaptogenic

3. chronic fatigue

4. dehydration

5. bone weakness

6. neurodegenerative disorders

Cautions:-


form.

Experiment-3

Aim-To study the macroscopic characters of Vinca


Edition 39th , Nirali Parkashan, Page no. 484-487.



Theory:

VINCA

Synonym- Periwrinkle

Bio. Source- It consists of dried whole plant of Catharanthus roseus Don belonging to

family Apocyanaceae


Leaves

Color- Green

Shape- Simple,petiolate, ovate or oblong, unicostate, reticulate, entire, brittle and

oppositely arranged

Apex- Acute and mucronate

Lamina- glabrous somewhat shiny

Margin- Entire with acute base

Flowers

Color- Violet, pink, white or carmine red in color

Shape- Flowers are bractate, pedicillate, complete, hermaphrodite, normally 2-3 cm in

cymarose axillary clusters.

Fruits are follicles with several black seeds

Odour- characteristics

Taste-Bitter


It mainly contains indole alkaloids (0.1-1.5%) of which vincristine and vinblastine are

medicinally important. Vinblastine contains indole alkaloid part called catharanthine

and dihydroindole alkaloid part called vindoline.Other alkaloids present are ajmalicine,

serpentine and tetrahydroalstonine.

Uses-

1. Vincristine and vinblastine are used in the treatment of cancer.

2. Vincristine sulphate is an antineoplastic agent which may act by arresting mitosis

at the metaphase.

3. It si used in the treatment of Hodgkin disease and choriocarcinoma.

4. It also possess hypotensive and antidiabetic effects

Cautions:- Do not taste the crude drug because it might be harmful to the human body

in crude form.

Experiment-4

Aim-To study the macroscopic characters of Rauwolfia





Theory

Synonym- Rauwolfia root, serpentine root, chootachand, sarpagandha

Bio. Source- it consists of dried roots and rhizomes of Rauwolfia serpentine Benth,

belonging to Family Apocyanaceae

MACROSCOPIC CHARACTERS-

Color- outer surface- dull greyish brown with faint longitudinal ridges.

Internal surface- pale yellow

Odour-Odourless

Taste- bitter

Size- About 8-15 cm long, 0.5-1.0 cm thick

Shape- Roots are subcylindrical, slightly tapering, somewhat tortuous, rarely branched

Fracture- Short and irregular


Rauwolfia contains atleast 30 indole alkaloids (0.7-2.4%).madicinally important indole

alkaloids are reserpine, rescinnamine, ajmalicine and serpentine.

Use-

1. Antihypertensive

2. Tranquillising agent and used in certain neuro-psychiatric disorders

Cautions:-


form.

Experiment-5

Aim-To study the macroscopic characters of Nuxvomica.





Theory

NUXVOMICA

Synonyms- Kuchla, karaskara, crow fig, semen strychni

Bio. Source- It consists of dried ripe seeds of Strychnos nuxvomica Linn. Belonging to

family loganiaceae


Color-outer surface is grey to greenish grey

Odour-None

Taste- Intensly bitter

Size- 10-30 mm in diameter and 406 mm in thickness

Shape- Disc shaped somewhat flat or irregularly bent and concavo-convex.

Margin- rounded or acute

Surface- silky due to presence o dense, closely oppressed radiating, outwardly directed

trichomes

Hilum is raised in the centre of flat surface.


Nuxvomica seed contains 1.5-5% of bitter indole alkaloids. Chief constituents are

Strychnine and brucine while vomicine, α- Colutrine, pseudostrychnine and strychnicine

are also present. Seeds contain 3% of fat.

Nuxvomica also contain a glycoside i.e. loganin, chlorogenic acid and fixed oil

Uses-

1. Bitter stomachic and tonic

2. CNS stimulant

3. Respiratory stimulant.

4. It is used in CNS depressants poisoning such as Barbiturate poisoning

Cautions:-


form.

Experiment-6

Aim-To study the transverse section and powder microscopy of Rauwolfia

References- 1.Kokate C.K., Practical Pharmacognosy, Edition 11th, Vallabh Parkashan,

Page no. 76-78.



Requirements- sample (rauwolfia root entire & powder), microscope, Glass slide,

Coverslip, glycerine (50%), phloroglucinol, HCl

Theory

Synonym- Rauwolfia root, serpentina root, choota chand, sarpagandha

Bio. Source- It consists of dried roots and rhizomes of Rauwolfia serpentina Benth,


MICROSCOPIC CHARACTERS-

Transverse section of root

1 CORK- stratified with 1-7 laters of small cells, 1-3 layers of larger cells, suberised,

larger cells lignified.

2. PHELLODERM- 10-12 rows of cellulosic parenchyma

3. Phloem- sieve tubes and parenchyma alternating with medullary rays

4. Medullary rays2-4 cells wide

5. Xylem- tatrach with small vessels, parenchyma, fibers,large celled medullary ras

6. Parenchyma of xylem and phloem, both lignified containing prisms and conglomerate

crystals of calcium oxalate and starch granules

7. Granular section staining yellow with iodine in phloem parenchyma

Transverse section of rhizome shows-

In addition to the above structure, cortex, pericycle with unlignified pericyclic fibres, a

small pith and perimedullary phloem in the periphery of pith, stone cells absent

POWDER MICROSCOPY

1 The powder is pale brownish-yellow in color with bitter taste.

2. Microscopic examination shows abundant starch grains, simple and compound (2-4

components), spherical, with a distinct hilum in the form of split.

3. Cork-stratified iso diametric cells sometimes lignified. Polygonal in surface view.

4. parenchyma- pitted, lignified

5. vessels- lignified, fairly narrow with bordered pits

6. Fibers are lignified, slightly pitted, found with or without attached vessels

Cautions:-


form.

Experiment-7

Aim-To study the transverse section of Datura and Vinca

References - 1.Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Edition 41,

Reprint 2008, Nirali Parkashan, Page no. 501-502



Requirements- sample (Datura leaf and catharanthus leaf), microscope, Glass slide,

Coverslip, glycerine (50%)

THEORY


Bio. Source- It consists of the dried leaves and flowering tops of Datura metel

Linn. And other species of Datura belonging to Family Solanaceae

MICROSCOPIC CHARACTERS:

Study of transverse section-

1. Datura leaf is dorsiventral i.e. having distinct upper and lower surfaces.

2. Stomata are of anisocytic type on both surfaces.

3. Epidermal cells are polygonal with thin cuticle, anticlinical walls, slightly straight

on the upper surface, wavy on the lower surface.

4. A single layer of elongated palisade cells is present below upper epidermis.

5. Next to palisade layer is a single row of rectangular cells containing rosette

calcium oxalate crystals and remainder of the mesophyll consists of spongy

parenchyma.

6. Leaf bears both covering and glandular trichomes, covering trichomes, uniseriate,

multicellular and conical, usually less than 35µ in diameter at the base, glandular

trichomes with unicellular stalk and uni- and multi-cellular head.

7. Midrib region shows collenchymatous cells on both surfaces.

8. Xylem bundles are arranged in an arc.

9. The space between collenchyma and vascular bundle is occupied by 6-8 rows of

cortical parenchymatous cells some of which are filled with calcium oxalate

THEORY:

VINCA

Synonym- Periwrinkle

Bio. Source- It consists of dried whole plant of Catharanthus roseus Don belonging to

family Apocyanaceae



1. Vinca leaf is dorsiventral.

2. Stomata are of anomocytic type on both surfaces.

3. Epidermal cells are polygonal with thin cuticle; anticlinal walls are straight on the

upper surface and wavy on the lower surface.

4. A single layer of elongated palisade cells is present below upper epidermis.

5. Mesophyll consists of 5-7 layers of spongy parenchymatous cells with

intercellular spaces.

6. the midrib region shows collenchyma on both surfaces blow epidermis

7. A zone of vascular bundles occupies the central region.

Experiment-8

Aim-To study the transverse section and powder microscopy of Withania

References- 1.Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Reprint 2008,

Nirali Parkashan, Page no. 13.79-13.81.

Shah N. B., Nayak B. S., Experimental Pharmacognosy, First Edition April,2008, S.


THEORY

Synonym- Asgandh, Winter cherry, withania root

Bio. Source: - It consists of dried roots and stem bases of Withania somnifera Dunal,

belonging to family Solanaceae

Requirements- sample (Withania root entire & powder), microscope, Glass slide,



Study of transverse section (T.S.)-

1. T.S. of root shows thin cork, composed of several layers of uniformly arranged,

thin-walled cells

2. Cork surrounds a broad cortex, composed of thin-walled, polygonal, irregular

parenchymatous cells containing starch grains.

3. Below cortex is a large wood, which consists of vessels, tracheids and fibres

transversed longitudinally by medullary rays.

4. Medullary rays are single celled and straight.

5. Longitudinal section shows vessels and tracheids with pitted thickening

Powder microscopy-

1. The powder is greyish in colour with characteristic odour and bitter and acrid

taste.

2. Microscopic examination shows abundant vessels and tracheids with pitted

thickening.

3. Starch grains, nearly all simple, spherical-ovoid with distinct central hilum are

found scattered or parenchymatous cells of cortex.

4. Cork cells are thin walled and polygonal in surface view.

5. Fibres are narrow, elongated with tapered ends.

Experiment-9

Aim-To study the transverse section and powder microscopy of Nuxvomica

References- 1. Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Reprint 2007,

Edition 39th, Nirali Parkashan, Page no. 476-479.



3. Kokate C.K., Practical Pharmacognosy, Reprint 2007, Edition 4th, Vallabh Parkashan,

Page no. 66-67.

Requirements- sample (Nux-vomica seed & powder), microscope, Glass slide,


Theory

NUXVOMICA



family loganiaceae



1. Epidermis- large, thick walled lignified cells with slit like pits.

2. Epidermal trichomes- thick walled, bent, twisted, and lignified with about 10

longitudinal ribs on the limb.

3. Inner layer of epidermis with collapsed cells.

4. Endosperm-thick walled cellulosic parenchyma of isodiametric cells.

5. embryo and endosperm both contain aleurone grains and fixed oil globules

6. Plasmodesma- communication of the protoplast of endosperm cells through the

cell walls by means of very fine protoplasmic threads.

Powder Microscopy-

1. The powder is yellowish-grey to greenish-grey in color.

2. Microscopical examination shows epidermis of testa with attached trichomes.

3. Trichomes are narrow lignified rods running longitudinally.

4. Endosperm cells from central region are large and very thick walled while those

from outer part, small and relatively thin walled.

5. A few fragments of endosperm show faint plasmodesma

Experiment-10

Aim-To perform the chemical test of Nuxvomica and datura

References- 1. Kokate C.K., Purohit A.P., Gokhle S. B., Pharmacognosy, Reprint 2007,

Edition 39th, Nirali Parkashan, Page no. 476-479.&501-502




Page no. 66-67.

Requirements- Sample (Nux-vomica powder), Test tubes, test tube stands and holders,

watch glass, UV lamp, Bunsen burner , Conc. H2SO4, Conc.. HNO3, Ammonium

Vanadate, methanolic Potassium KOH, Acetone, K2Cr2O7,

Theory

NUXVOMICA



family loganiaceae

THEORY




Chemical tests:

The thin section of nuxvomica seed is defatted and performs the following tests-

1. A section of endosperm is strained violet by a drop of ammonium vanadate in

sulphuric acid due to presence of strychnine.

2. A section of endosperm is strained crimson or orange-red by a drop of nitric acid

due to presence of brucine.

3. A thick section of drug is treated with iodine solution and concentrated sulphuric

acid. Endosperm cell walls stain blue (due to hemicellulose)

THEORY




Chemical tests:

1. Vitali-morin test-It is specific test for tropane alkaloids. Powdered sample

is moistened with nitric acid followed by evaporation to dryness and

addition of methanolic potassium hydroxide solution to the residue, a violet

color is produced.

2. On addition of silver nitrate solution to the solution of hyoscine

hydrobromide, Yellowish white ppt. formed which is insoluble in nitric

acid but soluble in dilute ammonia.

Experiment-11

Aim-To perform the chemical test of Rauwolfia and Cinchona

References- 1.Kokate C.K., Practical Pharmacognosy, Edition 11th, Vallabh Parkashan,

Page no. 76-78.


Vikas Page no. 97 &160-161


Page no. 36-37.

Requirements- sample (rauwolfia powder), Test tubes, test tube stands and holders,

watch glass, UV lamp, Bunsen burner Vanillin, acetic acid, Bromine water, ammonia,

Conc. H2SO4

Theory

RAUWOLFIA

Synonym- Rauwolfia root, serpentina root, chotta chand, sarpagandha

Bio. Source- it consists of dried roots and rhizomes of Rauwolfia serpentina Benth,


Chemical tests:-

1. Powdered drug is treated with sulphuric acid and

p-dimethylaminobenzaldehyde, a bluish-violet to red color is developed. The

test is specific for indole alkaloids.

2. 1% tincture of drug shows fluorescence in UV light.

CINCHONA

Synonym- Peruvian bark, Jesuit’s bark

Bio. Source- It consists of dried stem or root bark of the plant Cinchona succirubra, C.

ledgeriana, C. calisaya, C. officinalis and other species of Cinchona belonging to family

Rubiaceae

Chemical tests:-

1. Heat the cinchona powder with glacial acetic acid. Reddish brown fumes on the

cooler part of the test tube are seen.

2. Coarse powdered bark is treated with lime and extracted with alcohol. The

alcoholic extract is evaporated and residue is taken up with dilute sulphuric Acid,

the liquid gives a blue fluorescence.

3. Thalleioquin test- To 10ml of the extract, add 0.25 ml of bromine water and 2 ml

of dilute ammonia solution are added and heated if necessary, a bright green

colouration is produced.

Experiment-12

Aim-To perform TLC of given sample.

References-Shah N. B., Nayak B. S., Experimental Pharmacognosy, First Edition

April,2008, S. Vikas Page no. 255-257

Requirements- TLC Plate & Chamber, Capillary, oven, spraying bottle, Silica gel G,

Sample

Theory

Thin Layer chromatography

Principle- TLC has been included under both adsorbtion and partition. Separation may

result due to adsoption or partition or by both phenomenon depending upon the nature

of adsorbents used on plates and solvent system used for development.

Thin layer chromatography (TLC) is a chromatography technique used to separate

mixtures. Thin layer chromatography is performed on a sheet of glass, plastic, or

aluminum foil, which is coated with a thin layer of adsorbent material, usually silica

gel, aluminium oxide, or cellulose (blotter paper). This layer of adsorbent is known as

the stationary phase.

After the sample has been applied on the plate, a solvent or solvent mixture (known as

themobile phase) is drawn up the plate via capillary action. Because

different analytes ascend the TLC plate at different rates, separation is achieved.

Thin layer chromatography can be used to:

Monitor the progress of a reaction

Identify compounds present in a given substance

Determine the purity of a substance

Procedure:-1. Prepare the TLC plate and keep it for the saturation. Make the extract of

the powdered drug and the spot it on the saturated TLC plate. Make the solvent system

and let it saturate it for the half an hour. The run the solvent system till 3/4th of the plate.

Dry the plate on the hot plate and then spray it by the spraying agent. Let it get air dried

and the mark the spot and trace the spot on the tracing paper.

Results: - Report the Rf value.

Rf Value =

Distance travelled by solute

Distance travelled by solvent

Cautions:-

Do not misuse the chemicals and keep the plate properly in the solvent chamber.

pharmacognosy lab manual

Documents

main alkaloid hyoscine

species of datura

hyoscine hydrobromide

various alkaloids

experimental pharmacognosy

vikas page

color upper surface

color outer surface