GB475574A - An improved process for obtaining compounds of keratin splitting products which are rich in heavy metal - Google Patents

Abstract

Keratin degradation products containing a large amount of heavy metal are prepared by hydrolyzing keratin materials with acid to the gelatinous state or to the point where solution just occurs, and after reducing the product, treating it in solution with a heavy metal salt in quantity substantially exceeding that which the sulphydryl groups can bind as shown by the sodium nitroprusside test; the solution is then neutralized and poured into an organic solvent to precipitate the heavy metal compound. In an alternative process, the sulphydryl groups in the reduced product are partly or almost wholly removed by oxidation before the addition of the heavy metal salt. The products possess enhanced therapeutic properties. According to the examples: (1) the sulphydryl keratinic acid prepared according to Specification 412,366 is treated in aqueous solution with successive small quantities of auric chloride until the precipitate no longer redissolves, neutralized with caustic soda, filtered and stirred into alcohol; (2) a sulphydryl keratinic acid prepared by hydrolyzing hair with dilute hydrochloric acid, reducing with zinc and removing the zinc with hydrogen sulphide, is oxidized by evaporation of the solution in the air and the residue then dissolved in water, which may be saturated with sulphur dioxide, and treated as in (1) with auric chloride; (3) the sulphydryl albumose solution obtained by hydrochloric acid hydrolysis of wool or hair to the point of solution, followed by reduction with tin and removal of the metal with hydrogen sulphide, is evaporated to dryness in vacuo and an aqueous solution of the residue then treated with auric chloride as in (1); the residue may be precipitated from solution in alcohol before treatment with the auric chloride; (4) the sulphydryl keratinic acid prepared by the process described in Specification 412,366 is treated in aqueous solution with small quantities of an aqueous solution of silver nitrate until the precipitate remains undissolved on stirring, whereupon the solution is neutralized and poured into alcohol; instead of silver nitrate may be used mercuric acetate, stannous chloride or ferrous sulphate; (5) a sulphydryl keratinic acid obtained by reducing the acid hydrolysate of hair is oxidized by repeated evaporation of its aqueous solution in the air; to an aqueous solution of the residue an aqueous solution of copper acetate, stannic chloride or zinc acetate is added in portions and the product worked up as before. Reference has been directed by the Comptroller to Specification 412,366.