Patent ID: 6124482
Filing Date: 2000-09-26
Classification: C07D

Abstract:
A process for the isolation of 10-deacetyl baccatin-III from the recoverable part of a plant of Taxus species by crystallization comprising the steps of:(a) extracting the pulverised and optionally dried parts of a plant of Taxus species, with aliphatic alcohol,(b) preparing a partially concentrated alcoholic extract containing 10-DAB and paclitaxel,(c) treating extract with aliphatic ketones and separating the insolubles from the mother liquor by centrifugation or filtration,(d) treating the residue obtained after evaporation of the mother liquor of step (c) under vacuum with a mixture of water and aliphatic ketones solvent and removing the insolubles through a celite bed by filtration or centrifugation, the insolubles containing enriched paclitaxel residue which is further processed to obtain commercial quantities of paclitaxel,(e) extraction of the aqueous ketonic solution devoid of paclitaxel with aromatic hydrocarbons to less polar substances, followed by extraction with water immiscible aliphatic esters or chlorinated solvents,(f) evaporating the organic layer of (e) to dryness to obtain a semisolid residue from which crude 10-DAB is obtained by selective crystallizations, and(g) isolation and purification of 10-DAB.