FIELD: PREPARATION OF BIOLOGICALLY ACTIVE SUBSTANCES. SUBSTANCE: 10-deacetylbaccatine III is prepared from different parts of yew (Taxus sp.) by methods which consist in the following. In the first method, disintegrated parts of yew are treated by alifatic alcohol to produce alcohol extract containing 10-deacetylbaccatine III. If necessary, extract is diluted by water. Insoluble products are separated from water-alcohol solution by filtration, decantation, or centrifugation. Alcohol is almost completely removed from solution. 10-Deacetylbaccatine III contained in aqueous phase is extracted with appropriate organic solvent, which is then removed from extract solution. 10-Deacetylbaccatine III is selectively crystallized from thus concentrated solution. In the second method, initial alcohol extract of 10-deacetylbaccatine III is extracted by another organic solvent. Water-alcohol phase obtained is separated by decantation and diluted with water. Insoluble products are separated from water-alcohol solution by filtration, decantation, or centrifugation. 10-Deacetylbaccatine III is extracted from filtered off water-organic phase by organic solvent. The latter is completely or partly removed from organic extract and 10-deacetylbaccatine III is selectively crystallized from solution or residue in organic solvent. EFFECT: improved procedure. 32 cl
