Paclitaxel cephalomannine → Paclitaxel

Participants

Reaction Steps

The paclitaxel/cephalomannine solid is dissolved in a minimum volume of dichloromethane or acetone and adsorbed onto a solid support such as silica gel or celite. According to the present invention the solid support is silica gel. The ratio of sample to solid support is about 1:1 to about 1:6 (w/w), preferably about 1:3. The sample is air dried to a free flowing powder and applied to 2 inch to 9 inch inner diameter glass or stainless steel columns previously loaded with silica gel in about 1:200 to 1:350 (w/w), preferably 1:250 ratio of sample to silica gel and equilibrated with mobile phase. The mobile phase is chosen from a mixture of toluene/ethyl acetate from about 7:3 to 1:1 (v/v) or toluene/dichloromethane/ ethyl acetate from about 5:1:3 to 2:1:2 (v/v/v) or other combinations of containing toluene having similar elutropic power. It is noteworthy to mention that the toluene in the mobile phase facilitates the separation of paclitaxel from cephalomannine, presumably due to π-π interaction of the toluene with the aromatic ring of paclitaxel. The column is eluted in an isocratic manner at a low pressure (about 5 to about 10 PSI). Eluant fractions (1L) are collected at a rate of 35 mL per minute and monitored by analytical tic and/or hplc. The fractions containing paclitaxel are pooled together and concentrated under reduced pressure to provide a solid residue, which is re-crystallized from a suitable solvent, including but not limited to hexane-acetone or aqueous methanol, to provide clinical standard paclitaxel (purity >98%).

Provenance & Evidence