Patent GB-475182-A (GB)
Title: Process for the preparation in a water-soluble and atoxic form of inorganic compounds of heavy metals
IPC: A61K33/24
Filed: 1936-02-10
Abstract: Tetrapectic acid is prepared by saponification of pectic acid under such mild conditions that hydrolysis leading to the formation of tetragalacturonic acids does not occur.ALSO:Inorganic heavy metal salts of therapeutic value which are normally insoluble in water are combined with pectic acid (as defined below) to give water soluble compounds.  An aqueous solution of pectic acid may be reacted with a metal salt of a weak acid or with a metal salt of a strong acid with neutralization by soda, and the metallic pectinate be precipitated with alcohol; or an alkali metal pectinate may be reacted with a metal salt and the pectinate be precipitated.  In either case, to an aqueous solution or suspension of the pectinate is added a salt, acid, or base which normally would precipitate the heavy metal, and from the resulting solution, the new compounds, referred to as "acid-metallic pectinates" are precipitated by alcohol as a water-soluble powder.  Instead of first isolating the metallic pectinate, the pectic acid, metal salt, and reagent adapted normally to precipitate the heavy metal may be reacted in a single stage.  By neutralizing the "acid-metallic pectinates" with alkalies or alkaline-earths, double salts may be obtained, and in this connection sodium silver pectinate and sodium mercury pectinate are referred to; alternatively the "acid alkali or alkaline-earth salts" may be combined with a heavy metal salt. Pectic acid is defined to include pectins, bassaronic acid, polyuronic acids such as tetragalacturonic 2-acid or di- or tetrauronic acids, and tetrapectic acid. Tetrapectic acid is prepared by saponification of pectic acid under such mild conditions that hydrolysis leading to the formation of tetragalacturonic acids does not occur.ALSO:Inorganic heavy metal salts of therapeutic value which are normally insoluble in water are combined with pectic acid (as defined below) to give water soluble compounds.  An aqueous solution of pectic acid may be reacted with a metal salt of a weak acid or with a metal salt of a strong acid with neutralization by soda, and the metallic pectinate be precipitated by alcohol; or an alkali metal pectinate may be reacted with a metal salt and the pectinate be precipitated.  In either case, to an aqueous solution or suspension of the pectinate is added a salt, acid, or base which normally would precipitate the heavy metal, and from the resulting solution, the new compounds, referred to as "acid-metallic pectinates," are precipitated by alcohol as a water-soluble powder.  Instead of first isolating the metallic pectinate, the pectic acid, metal salt, and reagent adapted normally to precipitate the heavy metal may be reacted in a single stage.  By neutralizing the "acid-metallic pectinates" with alkalies or alkaline-earths, double salts may be obtained, and in this connection, sodium silver pectinate and sodium mercury pectinate are referred to; alternatively, the "acid-alkali or alkaline-earth salts" may be combined with a heavy metal salt. Pectic acid is defined to include pectins, bassaronic acid, polyuronic acids such as tetragalacturonic 2-acid or tetra-uronic acids, and tetrapectic acid.