Process for fractionating knotwood extract and using a liquid-liquid extraction to purify knotwood extract

摘要

The invention relates to a method for the fractionation of knotwood extract, which has been obtained by extraction of knotwood with a hydrophilic solvent. The hydrophilic extract is extracted with a lipophilic solvent to remove lipophilic impurities. The invention also relates to the use of a liquid-liquid extraction for the purification of hydrophilic knotwood extract. The present process provides a purified knotwood extract, which contains more than 90% lignans, flavonoids and stilbenes and less than 10% impurities selected from resin acids, fatty acids, sterols, juvabiones, triglycerides and combinations thereof.