| 摘要 |
Insulin is obtained from a pancreas extract prepared directly from ground pancreas tissue by extraction with an acidified aqueous extraction liquid containing an organic solvent, with or without intermediate removal in known manner of fatty constituents from said extract, by adding metal ions of zinc, cadmium, iron, nickel, cobalt, copper or manganese, separating off and then dissolving the separated protein fraction in a dilute aqueous acid and then recovering the insulin from the solution so formed. In one example, cow pancreas is extracted with alcohol containing hydrochloric, acid at pH 2.5, the pH of the liquid is adjusted to 7.5 to 8.5 with ammonia and the liquid is clarified, the pH is then adjusted to 2.5 with hydrochloric acid and an equal quantity of water added to precipitate fatty substances which are separated. Zinc chloride is added and the pH is adjusted to 6.0 with ammonia to precipitate the insulin and other proteins. After dissolution in hycrochloric acid of pH 2.5-3.0, insulin is recovered therefrom by known methods. Preferably the metal ions are added in the form of a salt in which the metal is present in its bivalent form and the pH of the extract is adjusted to 5.0 to 7.5. Specifications 566,351 and 726,219 are referred to. |
