Silymarin isolation from Silybum marianum oil expression residue - by extn. with ethyl acetate, defatting with petroleum ether, and work-up in aq. methanol

摘要

In recovering silymarin (silymarin I-IV) from the residue obtd. after removal of the major part of the oil from fruits of silybum marianum by cold pressing, (A) the comminuted residue is repeatedly extracted with ethyl acetate and the extract is sepd. from the residue and evapd., (B) either (1) the evapn. residue is defatted by repeated solid-liq. extn. with petroleum ether and is subsequently dissolved in MEOH, the soln. being sepd. from insolubles, or (2) the evapn. residue is dissolved in MEOH and the soln. is subjected to repeated liq.-liq. extn. with petroleum ether, (c) the methanolic soln. is partitioned between a chloro-substd. lower alkane and water, the aq. methandic phase being sepd. off and retained, (D) the chloroalkane phase is repeatedly stirred with water and MEOH and decanted off, (E) the combined aq. methandic phases are evapd., (F) the evapn. residue is suspended in a small amt. of MEOH, the suspension is stirred into water, and the ppte. is centrifuged off and repeatedly washed with water, and (H) the ppte. is dried in vacuo, ground, and again dried in vacuo. Silymarin (a mixt. of the polyhydroxyphenylchromanons Silymarins I-IV) is a hepatotropic agent, the activity of which is better than that of the individual components. Simple process gives god yields of a high (90-96%) purity prod.