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US 4,162,255 AGranted
Process for extracting aristolochic acids
AssigneeDr. Madaus & Co.
InventorsRolf Madaus, Klaus Gorler
Life of this patent
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Abstract
Aristolochic acids are obtained from aristolochic plant species by alkaline extraction, comprising: (a) extracting the aristolochic plant species in slightly alkaline medium; (b) acidifying the extract; (c) dissolving the precipitate in an organic solvent immiscible with water; (d) extracting the obtained solution with aqueous alkali; (e) acidifying the extract; and (f) separating and optionally recrystallizing the precipitated product.
Claims17
Process for obtaining aristolochic acids from aristolochic plant species by alkaline extraction, comprising:
- (a) extracting the aristolochic plant species in slightly alkaline medium comprising an aqueous solution of a secondary or tertiary alkali phosphate or an aqueous sodium bicarbonate solution;
- (b) acidifying the extract with a mineral acid to a pH of 5 to 3;
- (c) dissolving the precipitate in an ester of an aliphatic carboxylic acid of 1 to 10 carbon atoms of an alcohol of 1 to 10 carbon atoms, and filtering off insoluble components;
- (d) extracting the obtained solution with aqueous alkali;
- (e) acidifying the extract with a mineral acid to a pH value of 5 to 3;
- and
- (f) recrystallizing the precipitated aristolochic acids.
4 more elements
Dependencies are inferred from the claim text.