Process for isolation of saponins uttroside B and uttroside A from Solanum nigrum linn

An improved process for the isolation of saponins, uttroside B and uttroside A from whole plant of Solanum nigrum comprising the steps of:

• (i) extracting air dried powdered whole plant of Solanum nigrum with an aqueous polar solvent containing 10-20% water;
• (ii) removing the aqueous polar solvent under vacuum at 35-40° C. to obtain a residue;
• (iii) diluting the residue with methanol or ethanol and removing the unwanted insoluble solid impurities by filtration to obtain a clear filtrate;
• (iv) repeatedly precipitating the filtrate to obtain a precipitate of dried enriched saponin fraction with uttroside A and uttroside B;
• and
• (v) subjecting the precipitate to:
• (a) reverse phase silica gel column chromatography to obtain both uttroside A and uttroside B in pure form;
• or
• (b) refluxing in water for 48 hours to afford the uttroside B;
• or
• (c) refluxing in methanol in the presence of 1% silica gel to afford uttroside A.