METHOD FOR PRODUCING WATER-SOLUBLE POLYSACCHARIDES FROM LEAVES OF GREAT BURDOCK Russian patent published in 2018 - IPC C08B37/18 

FIELD: chemistry.

SUBSTANCE: invention relates to the production of biologically active substances from medicinal plant material and can be used to prepare water-soluble polysaccharides from the leaves of great burdock. Method provides for three-fold extraction of plant raw material purified by hot water, separation of plant material, precipitation of water-soluble polysaccharides by triple amounts of ethyl alcohol, filtering of the precipitate, washing and drying. And as a plant raw material, the leaves of great burdock ground to a linear size of 0.5-1 mm are used. Extraction is carried out at a raw material / extractant ratio of 1:15 in an ultrasonic bath at a frequency of 35 KHz for 10 minutes at a water temperature of 80°C. Plant material is separated by filtration. Precipitation is carried out with 95% ethanol at -18°C for 30 min. Precipitate is filtered through a previously dried ashless paper filter under vacuum at a residual pressure of 0.4-0.8 atm. Filter cake is washed successively with 15 ml of a 95% solution (3:1) of ethyl alcohol in purified water at a raw material / solution ratio of 1:15 and 10 ml of a mixture (1:1) of ethyl acetate and 95% ethyl alcohol with a raw material / solution ratio of (1:10); drying of the filter with the precipitate is carried out at a temperature of 100 to 105°C until a constant mass is achieved.

EFFECT: invention makes it possible to increase the yield of the desired product and shorten the duration of the extraction of water-soluble polysaccharides.

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