VITAMIN B12 DERIVATIVES HAVING PROLONGED ACTIVITY

1445495 Vitamin B 12 derivatives DR L ZAMBELETTI SpA 19 March 1974 [4 April 1973] 12209/74 Heading C2V A derivative of vitamin B 12 is obtained by a reaction in which the amido group of cobalamin is covalently linked to the hydroxyl groups of dextran. The derivative may contain 1À0 to 95% by weight of cobamide residues. It may be obtained by reacting dextran with cyanogen bromide and reacting the product with cobamide. The derivative has vitamin B 12 activity of prolonged duration. Examples are given.