Page 50 - Phytochemistry -1 (PG404) / Clinical Pharmacy 2nd level students ( 2019 )

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

5- Pipette 10 ml of the filtrate into a 250 m1 round bottorn flask (or conical

flask). Adjust the pH of the solution to 7-8 with few drops of 5%w/v
solution of Na 2CO 3. Add a mixture of 8m1 FeCL 3 and 12 ml water
and mix.
6- Heat on a boiling water bath under reflux for 20 minutes. Add 1 ml

Conc. HCL to render acidic and continue reflux for further 20 minutes,
shaking frequently until a precipitate is dissolved.
7- Cool, transfer and extract with 3 portions each of 25 ml of ether, passing

each fraction over anhydrous Na 2SO 4 (about 5 g.) placed in a small
funnel, receiving the ether extract into a 100 ml volumetric flask,
complete to volume with ether.

8- Pipette 10 ml of the etherial extract into a beaker, evaporate just to
dryness on a water bath and dissolve the residue in 10 ml 1N KOH
accurately measured, filter in case of any turbidity.

9- Without delay, measure the absorbance of the color of the resulting
solution at 500 nm using 1 cm cuvette.
10- Determine the content of total combined anthraquinones in senna

calculated as sennoside. A or B taking ''200" as the value-of E(1%,
1cm).
Each 1 mg of Rhein is equivalent to 1.8 mg of sennoside A or B.

Calculation:
Sennoside content of each tablet

Absorbance A 100 100 100
= 1.8
200 10 10 2
1.8 100
=
4

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