18 ♦ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

Experiment No. 4 Pharmacognosy

Experiment No. 4

1.0 TITLE :To study Morphological and Microscopical characteristics of Cinchona Bark.

2.0 PRIOR CONCEPTS :

Section cutting technique, staining, mounting and observation of transverse section of Cinchona

Bark.

3.0 NEW CONCEPT :

Proposition 1 : Morphological characters

It includes organoleptic characters and extra features.

Proposition 2 : Microscopical characters

It includes observation of important tissue components of transverse section of Cinnamon bark.

Proposition 3 : Adulterants

It is debasement of genuine crude drugs, which proved harmful.

4.0 LEARNING OBJECTIVE :

Intellectual Skill :

1. Ability to interpret the tissue components.

Motor Skill :

1. Ability to prepare thin transverse section of cinnamon bark.

2. To handle and observe instrument and crude drug correctly.

3. Labeling different component of cell.

5.0 REQUIREMENT SSSS :

Apparatus :

Microscope, watch glass, camel hair brush, glass slides, cover slips, beaker, dropper, filter paper,

forceps, test tubes, test tube holder, tripod stand, wire gauze, dissecting needle, sharp razor, etc.

Chemicals :

Phloroglucinol, Conc. HCI, Iodine solution, Glycerin, etc.

Crude Drug :

Cinchona bark.

6.0 DIAGRAM :

Fig. 4.1 Cinchona Bark and Plant

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION ♦ 19

Pharmacognosy Experiment No. 4

Fig. 4.2 T.S. of Cinchona Bark

(Refer colour diagrams given in Appendix-V)

7.0 STEPWISE PROCEDURE :

7.1 Synonyms :

English : Jesuit's bark, Peruvian bark.

7.2 Biological source :

It consists of dried bark of the cultivated trees of Cinchona calisaya Wedd., C. ledgeriana.

Mocns, C. officinalis Linn., C. succirubra Pav. ex. Klotzsch, or hybrids of either of the last two

species with either of the first two. It contains not less than 6 percent of total alkaloids of

cinchona. Family : Rubiaceae.

7.3 Macroscopy :

Organoleptic characters :

Odour : Slight and Characteristic Taste : Intensely bitter and slightly astringent.

7.4 Microscopy :

1. PERIDERM :

Cork : Several layers of thin walled, flat, polygonal cells with reddish brown content,

impregnated with suberin.

Phellogen : 2to 3 layers thin walled cells without any cellular content.

Pheloderm : 6 to 8 layers of thin walled rectangular cells without any cellular content.

20 ♦ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

Experiment No. 4 Pharmacognosy

2. CORTEX :

Several layers of thin walled tangentially elongated cells containing reddish brown matter.

Calcium oxalate crystals : 2 to 6 m long, microsphenoidal crystals

Starch grains : Rounded, 6 to 10 m in diameter.

Sclereides are absent.

Cavities (secretion canals) are present.

3. SECONDARY PHLOEM :

Sieve Tubes : The compact cells being about 200 m long and 15 to 20 m wide and

having narrow companion cells; most of the sieve tubes are compressed and collapsed.

Fibres : Nemerous, large, fusiform, lignified phloem fibres, having striated walls and

conspicuous tubular or funnel-shaped pits, mostly isolated, some times in groups of 2 to

3 fibres.

Pholem parenchyma : Thin, dark-reddish brown walls, some with micro-prisms of calcium

oxalate.

Medullary rays : One to three seriate, extended up to cortex cells, redially elongated

and contain starch grains.

7.5 Chemical constituents :

Alkaloids : Quinine, Quinidine, Cinchonine, Chichonidine

7.6 Uses :

1. Antimalarial 2. Antipyretic.

7.7 Allied drugs :

1. Cuprea bark, 2. Colombian bark.

7.8 Marketed preparations :

1. Cinchona extract, 2. Compound cinchona tincture.

7.9 Procedure

1. Clean the platform and issue the apparatus.

2. Issue the sample of crude drug.

3. Preparation of sample for sectioning.

� Boiling of the sample.

� Section cutting.

� Transfer the section in to Watch glass containing water.

(If crude drug is too hard, or in any case where subject teacher may feel then the

preparation of sample for sectioning is done before one hour or a day of the practical or

may be varied in certain cases)

4. Staining Process.

� Take a clean watch glass and add the staining solution to it.

� With the help of brush, transfer the section taken from watch glass containing water

to stain solution and keep it for 2 - 3 minutes.

� Transfer it to watch glass containing plane water, so that excess stain is washed

away. This section is ready for mounting.

5. Mounting Process.

� Transfer the section to be mounted on the glass slide with the help of brush.

� Add 1 - 2 drops of water on the section with the dropper.

� Place the clean cover slip over the section with the help of a forceps and needle.

� With the help of blotting paper, wipe out excess of water present outside the cover

slip. The slide is ready for observation.

6. Observation.

� Select a place in the laboratory for microscope, where sufficient light is available.

Set the microscope in such a way that the C-Arm towards to you and the objective

and mirror facing the light.

� Open the diaphragm completely with the help of the sub stage mirror. Adjust the

position so that the field of view is sufficiently illuminated.

� Place the slide prepared on the stage of the microscope at the centre, with the

section placed exactly in line with the stage window lying above the condenser.

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION ♦ 21

Pharmacognosy Experiment No. 4

� Fix the slide between the clips. Now the slide can be moved forward, backward or

sideways above the stage with the help of two screws provided on the mechanical

stage.

� Take observations.

7.10 Staining :

1. T.S. + Phloroglucinol + Conc. HCI (1:1)

Pink colour.

Lignified Phloem fibres

2. T.S. + Iodine

Blue colour.

Starch.

(Refer colour diagrams given in Appendix-V)

8.0 OBSERVATIONS :

8.1 Observation table for Macroscopy :

Sr. No. Test Observation

1. Colour

2. Odour

3. Taste

8.2 Observation table for Staining :

Sr. No. Test Observation Inferences

1.

2.

3.

9.0 CONCLUSION :

The given sample of crude drug is found to be ……………………………………. (Cinchona bark)

10.0 QUESTIONS :

Write answers to Q….Q….Q….Q….Q…. (Questions to be allotted by the subject teacher.

Subject teacher shall also add few more relevant questions)

1. Write two external characters of Cinchona.

2. Differentiate between stem, root and bark of Cinchona with the help of external characters.

3. The name 'Cinchona' is derived from which incident?

4. Which staining test is used to detect starch?

5. What will be the inferences after treatment of T.S. of Cinchona with Dil. Hydrochloric acid?

6. Which microscopic component is present in periderm of Cinchona bark?

Fig. 4.3

Fig. 4.4

22 ♦ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

Experiment No. 4 Pharmacognosy

7. Draw well labeled diagram of Cinchona bark.

8. Which microscopical test is used for identification of Lignified phloem and fibres?

9. Mention four species of Cinchona bark.

10. Which parasites are responsible for infection of Malaria? Give two names.

(Space for answer)

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION ♦ 23

Pharmacognosy Experiment No. 4

(Space for answers)