Patent GB-513304-A (GB)
Title: Process for the manufacture of therapeutically valuable gold compounds
IPC: A61K38/01
Filed: 1937-12-21
Abstract: 513,304. Gold keratinates. SCHERING AKT.-GES. (formerly SCHERING-KAHLBAUM. AKT.-GES.). Dec. 21, 1937, No. 35426. Void. Convention date, Dec. 23, 1936. Addition to 481,164. Samples furnished. [Class 2 (iii)] Alkaline earth metal and magnesium salts of gold keratinic acids are prepared by (1) reacting alkali metal gold keratinates with water-soluble salts of alkali earth metals or magnesium, (2) treating alkaline earth metal or magnesium keratinates with gold compounds, or (3) the simultaneous action of gold compounds and alkaline earth metal or magnesium oxides, hydroxides or carbonates on keratinic acids. The products, which can be precipitated from the reaction solution by means of a watermiscible solvent, possess therapeutic properties. The alkaline earth metal or magnesium keratinates used in (2) are prepared by the acid hydrohysis of a keratin, with or without reduction of the product, neutralization with ammonia, removal of reducing agent if present, treatment with an oxide, hydroxide or carbonate of an alkaline earth metal or magnesium, and precipitation with an organic solvent miscible with water. According to the examples (1) hair is hydrolysed with dilute hydrochloric acid and the liquid mixture heated with tin foil; after neutralization with ammonia, the tin is precipitated as the sulphide, and gold chloride hydrochloride then added ; on stirring into alcohol, sodium gold keratinate precipitates, and by treating an aqueous solution of it with calcium chloride and stirring into alcohol, calcium gold keratinate separates out ; (2) sodium gold keratinate prepared according to Specification 412,366 or Specification 357,189 is brought into aqueous solution with calcium chloride and the filtered product stirred into alcohol ; (3) hair is hydrolysed with dilute hydrochloric acid, the product neutralized with ammonia, calcium hydroxide added, and the filtered solution stirred into aclcohol ; to an aqueous solution of the resulting calcium keratinate, sodium aurichloride solution is added, and the whole stirred into alcohol to precipitate the calcium gold keratinate ; (4) a solution of gold chloride hydrochloride is added to a solution of a sulphhydryl-keratinic acid prepared according to Specification 412,366 and at the same time magnesium carbonate is added to maintain neutrality ; on stirring with alcohol, the magnesium salt of the gold sulphhydryl-keratinic acid precipitates. The samples furnished under Sect. 2 (5) are prepared by (1) hydrolysing wool with dilute hydrochloric acid, adding gold chloride hydrochloride to the neutralized solution, dissolving the precipitated gold keratinic acid in caustic soda solution, isolating the sodium salt by pouring into alcohol, treating an aqueous solution of the salt with magnesium sulphate, and separating the resulting magnesium gold keratinate by stirring into alcohol ; (2) adding strontium chloride to an aqueous solution of the sodium gold keratinate of (1), and stirring into alcohol to precipitate strontium gold keratinate ; (3) hydrolysing hair with dilute hydrochloric acid, reducing with tin, removing tin by means of hydrogen sulphate, adding- magnesium carbonate to an aqueous solution of the resulting sulphhydryl-keratinic acid, and treating an aqueous solution of the product with gold chloride hydrochloride to form the magnesium salt of the gold sulphhydrylkeratinic acid, which is isolated by stirring into alcohol ; (4) hydrolysing hair with dilute sulphuric acid, dialysing, evaporating to dryness, treating an aqueous solution of the residue with gold chloride hydrochloride whilst adding calcium hydroxide, and separating the resulting calcium gold keratinate.