Cobamic acid

Cobinic acid and cobinamide, which aie hnked to libose 3-phosphate, are known as cobamic acid and cobamide (5), respectively. 

The skeleton of vitamin 8,2 (i.e., the porphyrin nucleus minus C-20) is called corrin. The compound containing the corrin nucleus is edled a corrinoid. The compound containing the cobalt atom and the standard side chains in the free acid form is called cobyrinic acid, but cobyric acid when the side chains are at positions a, b, c, d, e, g, are in the amide form. Cobyrinic acid substituted with D-l-amino-2-propanol at position f is called cobinic acid. The substituted cobyric acid is called cobinamide. Cobinic acid substituted with d ribofuranose-3-phosphate at position 2 of the aminopropanol is called cobamic acid the substituted cobinamide is called cobamide. Many 8,2 vitamins and derivatives in which the heterocyclic base is 5,6-dimethylbenzimidazole are given the trivial name cobalamin see D. Dolphin, ed., 8,2, Wiley-Interscience, New York, 1982. 

The ribose 3 -phosphate-containing moiety in which the primary amide groups are hydrolyzed to carboxyl groups is designated cobamic acid (XII). The corresponding structure in which the primary amide groups are intact... 

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