pseudovitamin

A substance having a chemical structure very similar to that of a given vitamin, but lacking the usual physiologic action.

- p. B₁₂ cobamide cyanide phosphate, 3′-ester with 7-α-d-ribofuranosyladenine, inner salt; vitamin B₁₂ with adenine replacing dimethylbenzimidazole; one of several substances produced during anaerobic fermentation by certain organisms in bovine rumen contents; it is chemically closely similar to vitamin B₁₂ (cyanocobalamin) but without, in humans, the physiologic action of the vitamin.