摘要 |
The invention concerns a process for the preparation of sennosides A and B, wherein rheinanthrone-8-glucoside is oxidized with oxygen or an oxygen source to the sennosides A and B. According to the invention, the oxidation is carried out using active carbon as a catalyst, and, if desired, the obtained sennosides A and B are converted to their calcium salts using methanol precipitation from a calcium ion containing aqueous solution. |