Title: Vitamin B12
CAS Registry Number: 68-19-9
Synonyms: Cyanocobalamin; 5,6-dimethylbenzimidazolyl cyanocobamide; cobinamide cyanide phosphate 3￠-ester with 5,6-dimethyl-1-a-D-ribofuranosylbenzimidazole inner salt; LLD factor;
Lactobacillus lactis Dorner factor; extrinsic factor; antipernicious anemia principle
Trademarks: Anacobin; Bedoz; Behepan (Pfizer); Berubi (Cesra); Betalin-12 (Lilly); Betolvex (Dumex); Cobalin (Link); Crystamine; Cytacon (Goldshield); Cytamen (UCB); Cytobion (Merck KGaA); Docémine (Roussel Uclaf); Docigram (UCB); Fresmin (Takeda); Millevit (Abbott); Redisol (Merck & Co.); Rubesol; Rubramin PC (BMS); Vitarubin (Streuli)
Molecular Formula: C63H88CoN14O14P
Molecular Weight: 1355.37
Percent Composition: C 55.83%, H 6.54%, Co 4.35%, N 14.47%, O 16.53%, P 2.29%
Literature References: Prototype of the family of naturally occurring cobalt coordination compds known as
corrinoids. Analogs of vitamin B12 which differ only in the b-ligand of the cobalt are termed
cobalamins. Synthesized almost exclusively by bacteria. Dietary sources include fish, meat, liver, and dairy products; plants have little or no cobalamins. Also found in soil and water, the richest sources being activated sewage sludge (
see Milorganite) or manure. Converted by the body into its bioactive forms, methylcobalamin and cobamamide,
q.q.v., which serve as enzyme cofactors. Severe deficiency may result in megaloblastic anemia and/or neurological impairment. Isoln from mammalian liver: E. L. Rickes
et al., Science 107, 396 (1948); from cultures of
Streptomyces griseus: eidem, ibid. 108, 634 (1948); E. L. Rickes, T. R. Wood,
US 2563794 (1951 Merck & Co.). Fermentation process using
Pseudomonas denitrificans: R. A. Long,
US 3018225 (1962 to Merck & Co.). Purification from sewage sludge: P. J. Van Melle,
US 3057851 (1962 to Armour). Structure: D. C. Hodgkin
et al., Nature 176, 325 (1955); R. Bonnett
et al., ibid. 328. X-ray structure analysis: D. C. Hodgkin,
Fortschr. Chem. Org. Naturst. 15, 167-227 (1958). Stereochemistry: Stora,
Bull. Soc. Chim. Fr. 1959, 1421. Total synthesis: R. B. Woodward,
Pure Appl. Chem. 33, 145 (1973). Nomenclature: IUPAC rules,
ibid. 48, 497 (1976). Gastrointestinal absorption is dependent on Castle's intrinsic factor,
q.v., and
haptocorrin (R-protein); transport of the absorbed vitamin is mediated by
transcobalamins: B. Seetharam, D. H. Alpers,
Annu. Rev. Nutr. 2, 343-369 (1982); R. Gr?sbeck,
Clin. Biochem. 17, 99-107 (1984). Role of Co-C bond in B12-dependent reactions: J. M. Pratt,
Pure Appl. Chem. 65, 1513 (1993). Review of biosynthesis: A. I. Scott,
Angew. Chem. Int. Ed. 32, 1223-1243 (1993). Comprehensive description: J. Kirschbaum,
Anal. Profiles Drug Subs. 10, 183-288 (1981). Book:
B12 vols. 1 and 2, D. Dolphin, Ed. (Wiley-Interscience, New York, 1982) 672 and 506 pp.
Reviews: B. T. Golding in
Comprehensive Organic Chemistry vol. 5, E. Haslam, Ed. (Pergamon, New York, 1979) pp 549-584; "Vitamin B12" in
Vitamins, W. Friedrich, Ed. (de Gruyter, Berlin, 1988) pp 837-928. Review of chemistry and enzymology: K. L. Brown,
Chem. Rev. 105, 2075-2149 (2005).
Properties: Hygroscopic, dark red crystals. When exposed to air, may absorb ~12% water. The hydrated crystals are stable to air. Darkens at 210-220°. Not melted at 300°. [a]23656 -59 ± 9° (dil aq soln). Absorption max (water): 278, 361, 550 nm (A1%1cm 115, 204, 64). Odorless and tasteless. One gram dissolves in ~80 ml water. Aq solns are neutral, maximum stability in the pH range 4.5-5. Solns in this pH range can be autoclaved for 20 min at 120°. Soluble in alc. Insol in acetone, CHCl3, ether.
Optical Rotation: [a]23656 -59 ± 9° (dil aq soln)
Absorption maximum: Absorption max (water): 278, 361, 550 nm (A1%1cm 115, 204, 64)
Derivative Type: Zinc tannate complex
Synonyms: Cyanocobalamin zinc tannate
Trademarks: Depinar (Armour Pharm.)
Literature References: Long acting injectable vitamin B12 prepn. Prepn: Thompson,
US 2920015 (1960 to Armour). Comparative clinical study: A. Killander, I. Werner,
Acta Haematol. 40, 305 (1968).
Properties: Practically insol in water. On reconstitution forms a colloidal suspension.
Therap-Cat: Vitamin (hematopoietic).
Therap-Cat-Vet: Vitamin (hematopoietic).
Keywords: Vitamin/Vitamin Source; Vitamin B12.
