| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for economically preparing an extract containing a biologically active oligomeric polyphenolic compound. SOLUTION: This method comprises (a) subjecting a plant to extractin with hot water, (b) precipitating tannins from the obtained water phase by addition of a mineral salt, (c) treating the filtrate with ethyl acetate, (d) concentrating the obtained organic phase, (e) adding distilled water, (f) removing ethyl acetate by evaporation under reduced pressure, (g) washing the obtained water phase with a chlorinated solvent at least once, (h) eliminating the residual chlorinated solvent from the washed water phase and (i) drying the obtained water phase condensate to give the extract. The method for preparing the extract containing a biologically active oligomeric polyphenolic compound is economic due to no use of an expensive apparatus such as an ultrafilter. The obtained extract hardly contains an agrochemical. |
