Title: Vitamin B12r
CAS Registry Number: 14463-33-3
CAS Name: Vitamin B12-Co(II)
Synonyms: cob(II)alamin; 5,6-dimethyl-1-(3-
O-phosphono-a-D-ribofuranosyl)-1
H-benzimidazole monoester with cobinamide-Co(II) inner salt
Molecular Formula: C62H88CoN13O14P
Molecular Weight: 1329.35
Percent Composition: C 56.02%, H 6.67%, Co 4.43%, N 13.70%, O 16.85%, P 2.33%
Literature References: A one-electron reduction product of vitamin B12 containing a divalent cobalt atom. Undergoes a further one-electron reduction to vitamin B12s. Prepn: H. Diehl, R. Murie,
Iowa State Coll. J. Sci. 26, 555 (1952); R. O. Brady, H. A. Barker,
Biochem. Biophys. Res. Commun. 4, 373 (1961); H.-U. Blaser, J. Halpern,
J. Am. Chem. Soc. 102, 1684 (1980). Crystal structure: B. Kr?utler
et al., ibid. 111, 8936 (1989). Valence of reduced forms of B12: H. A. O. Hill
et al., Chem. Ind. (London) 1964, 197. Review of chemistry of B12r, B12s and analogs: R. Bonnett,
Chem. Rev. 63, 573-605 (1963); of prepns: D. Dolphin,
Methods Enzymol. 18, (Pt. C), 34-52 (1971). Role in enzymatic reactions: J. M. Pratt,
Pure Appl. Chem. 65, 1513 (1993).
Properties: Dark brown amorphous solid. Oxidized by air to aquocobalamin. Absorption max (H2O): 474, 404, 312, 289, 260 nm (log e 3.99, 3.88, 4.46, 4.29, 4.25).
Absorption maximum: Absorption max (H2O): 474, 404, 312, 289, 260 nm (log e 3.99, 3.88, 4.46, 4.29, 4.25)
Derivative Type: Vitamin B12s
CAS Registry Number: 18534-66-2
CAS Name: Cobinamide-Co(I) dihydrogen phosphate (ester) 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1
H-benzimidazole
Synonyms: cob(I)alamin; hydridocobalamin
Molecular Formula: C62H89CoN13O14P
Molecular Weight: 1330.36
Percent Composition: C 55.97%, H 6.74%, Co 4.43%, N 13.69%, O 16.84%, P 2.33%
Properties: Obtained as a gray-green product in solution.