Effects of Extraction Conditions on the Yield of Native Dihydroquercetin Containing More Than 97% (+)-2R,3R-Trans Isomer

The optimum parameters for the process of extraction of the dihydroquercetin (DHQ) isomer with the greatest antioxidant activity were identified. Use of ethyl acetate as extractant in this process was found to have clear advantages over other industrial solvents. An optimum method of extracting DHQ from larch wood with a large enantiomer excess was proposed. The method was developed and the quantitative content of the (+)-2R,3R isomer of DHQ extracted from wood of Larix sibirica Ledeb. was assayed.