Extract your plant material in water at waterbath at 80C. Then the extracts were centrifuged to remove the contaminants. The supernatant was concentrated via rotary evaporation method and precipitated with 85% alcohol. Then the precipitation was dissolved with water and dialyzed to remove the small molecules. The dialyzed solution was freeze-dried to yield polysaccharides powder.

or

The supernatant was then passed through a 0.22 μm filter and concentrated with a 5 kDa Amicon PM5 membrane in an Amicon concentrator to obtain crude polysaccharides.

-You can also use other extraction methods viz. ultrasound-assisted water extraction (UAE), microwave-assisted water extraction (MAE) and supercritical fluid extraction too. Try it...

Gud luck!!!

:)

Polysaccharide like macro molecular bio-active compound are extracted through the " Hot water extraction and alcohol precipitation "method.

by this method extract your plant material by aqueous medium ,after extraction if you follow the autoclaving of the same extract at 120 c for 20 min will give the best result. cool down it and centrifuge at 1000 rpm at 4-9 C for 10-15 min

Now add 96% ethanol to the supernatant liquid and left it at 4C until precipitation, repeat the same process 3 times

collect the precipitated material dialysed and dry it

for the better precipitation a reagent like trichloroacetic acid can be added along with alcohol , these reagent cause the precipitation of protein only not the Polysaccharide. for that add 3 % trichloroacetic acid to the extract until the

solution becomes murky (thicker )

@Manish Singh : u mean if we add tricloroacetic acid it can precipitate protiens only.. and after dat we have to add alcohol for polysaccharides. ..is it..?

ya it is, and then have to separate the Polysaccharide and protein , there are different method available for the separation ,

if u dissolve methanolic extract in water and than partition it with ethlacetate most of the components will remove from water and polysaccharides in their natural form will b in water n this water layer after column chromatographic purification give many many nl formatiraly occurring polysaccarides in natura

naturally occurring polysaccarides

Thankyou everyone.

Can you explain all steps of extrction method of polysaacchrides.?

Mr Thakur, you can try flash chromatography or CC over sephadex instead of a silica gel column. Hope you are referencing to phytochemical methods by Prof.J.B.Harborne. It is a good book for NPC researchers.

@Bandana polysaccharides. are not extracting in methanol extract. The water insoluble portion that you get are phenolic compounds like rutin or quercitin. So try to isolate this .

Dear Bandana The insoluble portion in MeOH extract is not the polysaccharide component. But for the isolation of polysaccharide only aq. extraction is required followed by precipitation and purification. 

Please see the attachment also

Try to solublize your water insoluble portion again in methanol. Many times due to hot percolation many compounds deformed in their structure. While during cold it is not possible them to reshape in their structure. Thats why many time extract is not solublize totally in respective solvent from which they are extracted. 

If you want to extract polysachride and  it is good also because you already extracted herb by all solvent from Pet Ether to Methanol. Now  polysacchrides are left which will extracted by hot water extraction. So collect aq. fraction and proceed for polysacchride isolation. You can precipitate this fraction in methanol 1:5 ratio to get certain polysacchrides. Good Luck

For the extraction of polysaacchrides, ethanol is the best solvent extraction medium, due to the character of physio chemical parameters. Further purification made by selective chromatogarphy separation system.

Good luck

Article Extraction of Polysaccharide from Spirulina and Evaluation o...