METHOD FOR ISOLATION OF BIOLOGICALLY ACTIVE DIHYDROQUERCETIN ISOMERS Russian patent published in 2008 - IPC A61K36/15 

FIELD: chemical and pharmaceutical industry.

SUBSTANCE: ground larch wood is extracted with 90-95 % ethanol at 55-66°C for 1-2 hours. Extract is filtered, propylene glycol is added, mixture is boiled down. Obtained precipitate is treated with 5 % sodium chloride solution in softened water at 20-30°C. Formed resin is separated, obtained flavonoid complex is eluated from column with 90-99 % ethanol, deposited precipitate is crystallized, filtered and dried. Obtained product representing biflavonoid complex is ground followed by dissolving in methanol/water (10:90) mixture and is subjected to reverse phase chromatography at column temperature of 0°C, wherein as mobile phase β-cyclodextrine solution in methanol/water (10:90) mixture is used. Collected fractions containing individual enantiomers are boiled down on rotor evaporator in vacuum under rest pressure of 10-20 mBar and at temperature of at most 60°C. Obtained rests are dried in vacuum under rest pressure of 10-20 mBar and at temperature of at most 60°C up to constant mass. Dry rests are extracted with 50 ml of absolute methanol at room temperature to separate target products from β-cyclodextrine. Extracts are filtered trough glass filter N 3-4, boiled down on rotor evaporator in vacuum under rest pressure of 10-20 mBar and at temperature of at most 50°C. Dried rests are dried in vacuum under rest pressure of 10-20 mBar and at temperature of at most 50°C.

EFFECT: complex of increased purity.

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