Patent GB-683083-A (GB)
Title: Improvements in or relating to hypotensive compositions and methods of making the same
IPC: C07G5/00
Filed: 1950-04-26
Abstract: A mixture of hypotensive alkaloids is isolated from veratrum plants by a process comprising the steps of: obtaining a solution of the veratrum alkaloids in an aqueous solution of a non-oxidizing non-reducing acid, e.g. acetic acid, adding sulphate ions to the solution, preferably in the form of ammonium sulphate, to precipitate undesired alkaloids as sulphates; rejecting the thus formed insolubles; rendering the resulting solution alkaline to produce a precipitate of alkaloids; dissolving this precipitate in chloroform; evaporating the solution to dryness; taking up from the residue in benzene those alkaloids soluble therein; and recovering the benzene-soluble alkaloids as a hypotensive composition.  The initial solution of veratrum alkaloids in the aqueous acid may be obtained by the steps of extracting veratrum plants with an organic alkaloid solvent made alkaline with ammonia; replacing such solvent and ammonia with a water-miscible organic alkaloid solvent; mixing this solution with an aqueous solution of the acid and rejecting material insoluble in the last-mentioned solution.  Suitable organic alkaloid solvents are chloroform, carbon tetrachloride, acetone, benzene and ether.  Suitable water - miscible alkaloid solvents are methyl, ethyl, propyl, iso-propyl, and hexyl alcohols, dioxanes, carbitols, glycerine, propylene glycol, and methyl-, ethyl-, butyl- and benzyl-glycol ethers.  Alternatively, the initial solution of veratrum alkaloids in aqueous acid may be made by the steps of extracting veratrum plants with an aqueous solution of acetic acid; rendering the solution alkaline to precipitate the alkaloids; recovering in chloroform the chloroform-soluble alkaloids, the insolubles being rejected; evaporating the resulting solution to dryness; and dissolving the residue in the aqueous acid.  Citric, tartaric, sulphuric and hydrochloric acids or mixtures thereof may be used instead of acetic acid.  The final residue from the benzene solution may be further purified by solution in acetone, discarding any insoluble material or crystalline precipitate and recovering the remaining acetone-soluble alkaloids.  Instead of the benzene and acetone extractions, a single ether extraction may be made.ALSO:A mixture of hypotensive alkaloids is isolated from veratrum plants by a process comprising the steps of: obtaining a solution of the veratrum alkaloids in an aqueous solution of a non-oxidising non-reducing acid, e.g. acetic acid, adding sulphate ions to the solution, preferably in the form of ammonium sulphate, to precipitate undesired alkaloids as sulphates, rejecting the thus formed insolubles; rendering the resulting solution alkaline to produce a precipitate of alkaloids; dissolving this precipitate in chloroform; evaporating the solution to dryness; taking up from the residue in benzene those alkaloids soluble therein; and recovering the benzene-soluble alkaloids as a hypotensive composition.  The initial solution of veratrum alkaloids in the aqueous acid may be obtained by the steps of extracting veratrum plants with an organic alkaloid solvent made alkaline with ammonia; replacing such solvent and ammonia with water-miscible organic alkaloid solvent; mixing this solution with an aqueous solution of the acid and rejecting material insoluble in the last-mentioned solution.  Suitable organic alkaloid solvents are chloroform, carbon tetrachloride, acetone, benzene and ether.  Suitable water-miscible alkaloid solvents are methyl, ethyl, propyl, iso-propyl, and hexyl alcohols, dioxanes, carbitols, glycerine, propylene glycol, and methyl-, ethyl-, butyl- and benzyl-glycol ethers.  Alternatively, the initial solution of veratrum alkaloids in aqueous acid may be made by the steps of extracting veratrum plants with an aqueous solution of acetic acid; rendering the solution alkaline to precipitate the alkaloids, recovering in chloroform the chloroform-soluble alkaloids, the insolubles being rejected; evaporating the resulting solution to dryness; and dissolving the residue in the aqueous acid.  Citric, tartaric, sulphuric and hydrochloric acids or mixtures thereof may be used instead of acetic acid.  The final residue from the benzene solution may be further purified by solution in acetone, discarding any insoluble material or crystalline precipitate and recovering the remaining acetone-soluble alkaloids.  Instead of the benzene and acetone extractions, a single ether extraction may be made.