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Sennosides:- B.S, Isolation, Identification Test, TLC (Notes)


Senna, the popular drug uses for constipation was introduced by Arabian physician and they use their leaves and pods. The two varieties of Senna are the Cassia acutifolia Family Leguminosae (popularly known as Alexandrian or Khartoum Senna) and the other variety is Cassia angustifolia (Tinnevelly senna). The drug contains important phytoconstituents sennoside responsible for their purgative activity.

Production of Sennoside:
Method A:
• The dried senna leaves extracted with 70 percent methanol.
• Shake the drug with methanol for around 4 hours at room temperature.
• Filter the extract and reduce the volume to 1/8 under vacuum.
• The extract is acidified to pH 3 with the help of Hydrochloric acid.
• After acidification filtration is done and removes any soluble aglycone with chloroform.
• The filtrate is neutralized with liquid ammonia and then centrifuge to isolate the sennoside.
Method B:
• The extraction of the crude drug was performed with the help of benzene for two to three hours with frequent shaking at room temperature.
• Dry the residue (marc) left after the extraction with benzene at oven or room
temperature which should be not exceeded to 40°C. The dry drug or marc should be extracted with 70 percent methanol for 4-6 hour on shaker at room temperature. Repeat the same process with fresh methanol for 2 hours.
• Club both the methanol extract and concentrate to 1/8 volume under reduced pressure. The pH is adjusted to 3 with hydrochloric acid and kept on side for 3 hours afterwards filter it. Anhydrous calcium chloride dissolves in denatured spirit and added to the filtrate with vigorous shaking.
• Maintain the pH 8 of the solution by ammonia solution and kept aside for two hours. Filter the solution and dry the precipitate over dessicant like phosphorus pentaoxide in a desiccator.
Estimation of Sennoside:
Hot water is useful for the extraction of anthraquinone glycosides. Acidified the aqueous extract and treat with chloroform to make free the aglycone which is largely present in the solution.
First neutralize the solution and then centrifuge it afterwards add ferric chloride to the solution.

Reflux the solution and further acidified it to bring oxidation and hydrolysis. The
aglycone present should be extracted with ether and re dispersed in the magnesium acetate solution. Measure the absorbance of the sennoside and express the concentration in comparison to sennoside B at 515 nm.
The main use of sennoside is cathartic. It may be used in habitual constipation or
occasional constipation. The sennoside glycoside absorb in the gastro intestinal tract and aglycone portion released in the colon. The released aglycone stimulates and irritates the colon. Thus movement in the colon portion is increased due to local action. The peristalsis movement is increased which generate soft and bulky stool.