Patent ID: 6107486
Filing Date: 2000-08-22
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 CH.sub.2 Cl.sub.2 solvent, wherein said adsorbent is a silica gel adsorbent;(2) passing through said column CH.sub.2 Cl.sub.2 containing a dissolved starting plant material containing at least about 60% by weight 20(S)-camptothecin, said starting plant material being selected from the group consisting of Camptotheca acuminata;(3) eluting said column by adding to the column a pure CH.sub.2 Cl.sub.2 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;(4) eluting said column with CH.sub.2 Cl.sub.2 made more polar than said solvent(s) in step (1), (2), and (3) by added lower alkanol; and(5) crystallizing said 20(S)-camptothecin from the eluant resulting from said elution (4).