Patent ID: 6156897
Filing Date: 2000-12-05
Classification: C07D

Abstract:
A method of purifying 20(S)-camptothecin which comprises the steps of:(1) charging a column with an adsorbent compound and wetting said compound with a wetting solvent, wherein said adsorbent is a silica gel adsorbent, an alumina adsorbent, a magnesium silicate adsorbent, a magnesia adsorbent, a carbon adsorbent, a diatomaceous earth adsorbent, or a mixture thereof;(2) passing through said column a starting material containing a starting material solvent and a starting plant material containing at least about 60% by weight 20(S)-camptothecin, said starting plant material being selected from Camptotheca acuminata, Mappie foetida Miers, Ophiorrhiza mungos, and Erratama heyneana;(3) eluting said column charged with said starting material by adding to the column a developing solvent that enables components more polar than 20(S)-camptothecin and components less polar than 20(S)-camptothecin to surpass 20(S)-camptothecin during elution through the column and to clear the column before the 20(S)-camptothecin;wherein the wetting solvent, the starting material solvent and the developing solvent can be the same or different;(4) eluting said column with a solvent more polar than said solvent(s) in step (1), (2) and (3); and(5) crystallizing said 20(S)-camptothecin from the eluant resulting from said elution (4).