ABSTRACT
Vitamin B12 is a cobamide, where 5,6-dimethylbenzimidazole is bonded by a glycosyl group from its N to the C of the ribose and additionally attached by a bond between the N and the Co. The cobalamin structure is indicated as Cbl. The oxidation state of cobalt can be shown either after the cob prefix in the compound name, for example, cob(I)alamin or cob(III) alamin, or in the subscript, where vitamin B12s demonstrates the +1 oxidation state, vitamin B12r as the +2 oxidation state and vitamin B12 as the +3 oxidation state. When a number is included in the vitamin B12 name, it signifies the position where substitution has taken place; for example, cobalamin that lacks a CH3 group at position C5 is named as C5-nor-(CN)Cbl. Cobamic acid is formed when cobinic acid is substituted at position 2 of aminopropanol by a-D-ribofuranose 3-phosphate, where its hexaamide is called cobamide. Complete hydrolysis of vitamin B12 gives cobyrinic acid.
