| 摘要 |
The present invention provides a process for obtaining laxative compounds from senna drug, wherein a) the senna drug is extracted with aqueous methanol by countercurrent percolation and the extract concentrated at a temperature of >/=50 DEG C. until the methanol has been completely removed from the extract; b) the extract obtained is purified by continuous liquid-liquid extraction with an organic solvent; c) the refined material (raffinate) obtained is transferred to a crystallisation apparatus, acidified, while stirring, to a pH of 1.5 to 2.0, seeded with sennoside crystals, left to crystallise while stirring and the crystalline crude sennoside obtained separated off; d) whereafter, the crude senno- dies are, if desired, recrystallised and optionally e) 10 parts by weight of the mother liquor from c) mixed, while stirring, with 2 parts by weight of sodium chloride and the semi-solid mass coagulated on the surface is decanted off, washed and optionally extracted with 95% methanol and the methanol fraction concentrated and the residue dried. n |
