METHOD FOR ISOLATION OF BIOLOGICALLY ACTIVE DIHYDROQUERCETIN ISOMERS Russian patent published in 2007 - IPC A61K31/35 

FIELD: chemical and pharmaceutical industry.

SUBSTANCE: ground larch wood is extracted with 90-95 % ethanol at 55-66°C for 1-2 h; extract is filtered; propylene glycol is added; mixture is boiled out; obtained rest is treated with 5 % sodium chloride solution in softened water at 20-30°C; and obtained resin is separated. Obtained flavonoid complex is eluted from column with 90-95 % ethanol; eluate is boiled out, precipitated with water cold to 0-2°C; deposited precipitate is crystallized, filtered, and dried. Obtained product representing bioflavonoid complex is ground followed by dissolving in methanol/water (10:90) mixture and subjected to reverse phase chromatography wherein as mobile phase β-cyclodextrine solution in methanol/water (10:90) mixture is used, and column is cold to 0°C. Collected fractions of individual enantiomeres are boiled out and dried.

EFFECT: complex of increased purity.

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