The extraction of rutin from flower buds of Sophora japonica

The efficiency of extraction of rutin from Sophora japonica is improved by ultrasound but is dependent on the solvent employed. Rutin is a compound wi th antioxidant activity and aqueous solvents appear to be unsuitable for ul trasonic extractions due to the formation of free radicals from the insonat ion of the solvent. The application of ultrasound to methanolic extraction gave a significant reduction in extraction time and an increase in maximum yield. (C) 2001 Elsevier Science B.V. All rights reserved.