| 摘要 |
In the preparation or purification of crystalline insulin an aqueous insulin solution (the insulin being obtained by extraction with an aqueous acidic solution of a lower (C1-4) aliphatic alcohol) is contacted with an aminocellulose anion exchanger and is subsequently eluted therefrom. The insulin-containing solution may have a pH of between 5.5 and 8.0 and is preferably about 6.0 to 7.5. The adsorption is preferably carried out in the presence of anions e.g. those of buffers such as sodium potassium phosphate and ammonium acetate which have a pH value within the adsorption range. Elution may be performed using either an acid (pH 1 to 5 preferably pH 3.5 to 4) or a base (pH 8.5 to 11 preferably 8.5-9) e.g. with sulphuric, hydrochloric or phosphoric acid, ammonia, sodium or calcium hydroxide. Recovery from the eluant may be by precipitation e.g. with zinc salts (preferred), other soluble heavy metal salts, alkali metal or ammonium salts, hydroxides or hydrohalides. Specified aminocelluloses are those obtained by the reaction of alpha cellulose with 2-aminoethyl sulphuric acid, 2-chloroethylamine, 3 - dimethylaminopropyl sulphuric acid, 2 - chloropropylamine, 1 : 3 - diamino - 2 - sulphato - propane sulphate monohydrate, 2 - (2 - sulphatoethyl) pyridine, potassium (disulphatoethyl) amine monohydrate, and sulphatoethylenediamine hydrochloride. Others mentioned are the reaction products of cellulose including cellulose-containing fabrics e.g. cotton, with epichlorhydrin and an amino alcohol e.g. ethanolamine and iminized exchangers e.g. the reaction product of 2-aminoethoxy cellulose and 2-aminoethyl sulphuric acid. Quaternarized amino-celluloses may also be used. Preferred exchangers are the lower (C1-4) dialkylamino lower alkyl cellulose compounds. A continuous process is described wherein the anion exchanger is a sodium hydroxide treated cotton belt which has been reacted with dimethylaminoethyl sulphuric acid. |
