GB903421A - Process for the production of cobalamin/peptide compositions - Google Patents

Abstract

Cobalamin-peptide complexes are prepared by mixing a cobalamin with a peptide from corn steep liquor. The process may be effected by using heat sterilised and filtered corn steep liquor, preferably the latter has been maintained at an acid pH e.g. below about 3. Most preferably (a) the peptide is obtained from the said liquor by extraction therefrom into an organic solvent and re-extraction into water, and (b) the corn steep liquor or peptide is treated with cyanide ions prior to mixing into cobalamin. The cobalamin-peptide complexes may be precipitated from aqueous solutions containing, e.g. (i) at least 1000 and preferably about 5000 micro g/ml of cobalamin when using acetone as precipitating agent, or (ii) about 500 micro g/ml when using ammonium sulphate as said agent. It is preferred to use such a quantity of cobalamin that the solutions have an optical density ratio of 0.7-1.3 at 278 and 361 mm ; such solutions are stated to have generally a cobalamin/peptide ratio of 1:3-9. In the examples glucose and phenol are optional additives to the corn steep liquor prior to extraction with phenol/benzene, to which butyl acetate may be added before the aqueous extraction step, and the aqueous layer may be washed with butanol. In example 3, solid cobalamin/peptide complex was isolated by freeze-drying of a solution having a cobalamin/peptide ratio of 1:9.8 and an optical density ratio of 1:1.25 at 278 and 361 mm . The complexes may be made up into pharmaceutical preparations using solid or liquid diluents.