6045. Methylcobalamin

Nomenclature

CAS number: 13422-55-4
Co-Methylcobinamide dihydrogen phosphate (ester) inner salt 3′-ester with 5,6-dimethyl-1-α-d-ribofuranosyl-1H-benzimidazole-κN3; methyl-5,6-dimethylbenzimidazolylcobalamin; mecobalamin; methyl vitamin B12; MeCbl; Algobaz (Labaz); Hitocobamin-M (Hishiyama); Methycobal (Eisai); Methylcobaz (Labaz); Xobaline (Delano).
C63H91CoN13O14P; mol wt 1344.38.
C 56.28%, H 6.82%, Co 4.38%, N 13.54%, O 16.66%, P 2.30%.

Description and references

One of the biologically active forms of vitamin B12, q.v.; differing only by the substitution of a methyl for the cyano group. Coenzyme required in the biosynthesis of methionine from homocysteine. Identification as requirement for methionine biosynthesis by E. coli: R. L. Kisliuk, D. D. Woods, Biochem. J. 75, 467 (1960) PubMed; J. R. Guest et al., Nature 195, 340 (1962) DOI PubMed. Prepn: O. Müller, G. Müller, Biochem. Z. 336, 299 (1962); D. Dolphin, Methods Enzymol. 18, Pt. C, 34 (1971); D. Autissier et al., Bull. Soc. Chim. Fr. 1980, part 2, 192. Interrelationship with folate metabolism: B. Shane, E. L. R. Stokstad, Annu. Rev. Nutr. 5, 115-141 (1985) DOI PubMed. General review: “Vitamin B12” in Vitamins, W. Friedrich, Ed. (de Gruyter, Berlin, 1988) pp 837-928. Review of role in methyltransferase reactions: R. G. Matthews, Acc. Chem. Res. 34, 681-689 (2001) DOI PubMed. Review of clinical experience in treatment of hyperhomocysteinemia and peripheral neuropathy: Y.-F. Zhang, G. Ning, Expert Opin. Invest. Drugs 17, 953-964 (2008) DOI PubMed.

Chemical structure

Properties

Bright red crystals from water/acetone. uv max (pH 7): 522, 342, 266 nm (ε 9357, 14416, 19897); (0.1N HCl): 462, 304, 264 nm (ε 9599, 22855, 24737).

Therapeutic Category

Vitamin; enzyme cofactor. In treatment of hyperhomocysteinemia and peripheral neuropathy.

Keywords

Vitamin/Vitamin Source; Vitamin B12; Enzyme Cofactor