Process for preparing a therapeutically useful extract from Brackenridgea zanguebarica, extract and such a medicine

摘要

1. Process for preparing an extract of Brackenridgea zanguebarica containing sequoiaflavone useful in therapeutics, said process, which involves the use of two extracting solvents, is characterized in that 1) leaves of Brackenridgea zanguebarica dried and groud beforehand, are subjected to an extraction with a solvent selected from the group constituted by a) acetone, b) acetone-water mixtures having a volume ratio CH3 COCH3 -H2 O higher than or equal to (3:7) v/v, and c) C1 -C3 lower alkohol-water mixtures having a volume ratio water-alkohol comprised between (3:7) v/v and (1:1) v/v, at a temperature comprised between 45 and 60 degrees C ; 2) the extract thus obtained is subjected to a treatment selected from the group constituted by a) the extraction by means of a solvent selected from the group comprising C1 -C4 halogenated aliphatic hydrocarbons, and the mixtures thereof, in order to extract the active substance soluble in said solvent, and to remove the largest part of the indesirable substances non soluble in said solvent, and b) the treatment by means of a solvent selected from the group comprising C5 -C7 aliphatic hydrocarbons, C5 -C6 cycloaliphatic hydrocarbons, aromatic hydrocarbons and the mixtures thereof, in order to remove the largest part of the indesirable substances in said solvent, the active substance being insoluble in said solvent ; and 3) the resulting liquid medium is concentrated at a temperature lower than or equal to 50 degrees C under reduced pressure.