Title: Cobamamide
CAS Registry Number: 13870-90-1
CAS Name: Co-(5￠-deoxyadenosine-5￠) deriv of 3￠-ester of cobinamide dihydrogen phosphate (ester) with 5,6-dimethyl-1-a-D-ribofuranosyl-1
H-benzimidazole, inner salt
Synonyms: cobamamidum; coenzyme B12; DBC; adenosyl-B12; 5￠-deoxyadenosyl-B12; 5￠-deoxyadenosylcobalamine; dibencozide; dibenzcozamide; dimebenzcozamide; 5,6-dimethylbenzimidazolylcobamide coenzyme; 5,6-dimethylbenzimidazolylcobamide 5￠-deoxyadenosine; vitamin B12 coenzyme
Trademarks: Actimide (Tobishi); Ademide (Toyo Jozo); Betarin (Beta); Calomide (Yamanouchi); Cobalion (Houd?; Cobaltamin S (Wakamoto); Cobanzyme (Bouchara); Cobazymase (Bouchara); Coenzile (A.T.I.); Dolonevran (Dausse); Enzicoba (Farmasa); Héraclène (Mauchant); Hi-Fresmin (Takeda); Hycobal (Eisai); Indusil (Diamant; Recordati); Ripresil (Erba); Sabalamin (Santen); Xobaline (Albert-Roussel)
Molecular Formula: C72H100CoN18O17P
Molecular Weight: 1579.58
Percent Composition: C 54.75%, H 6.38%, Co 3.73%, N 15.96%, O 17.22%, P 1.96%
Literature References: The coenzyme is the metabolically active form of vitamin B12: Barker
et al., Proc. Natl. Acad. Sci. USA 44, 1093 (1958); Weissbach, Taylor,
Vitam. Horm. 26, 395 (1968). Isoln from a culture of
Propionibacterium shermanii: Barker
et al., J. Biol. Chem. 235, 181, 480 (1960);
Biochem. Prep. 10, 27 (1964). Prepn of aquocobalamin and 2￠,3￠-
O-isopropylidene-5￠-
O-p-tolylsulfonyladenosine: Hogenkamp, Pailes,
ibid. 12, 124 (1968); from treatment of a cobalamin-thiol complex: Murakami
et al., US 3461114 (1969 to Yamanouchi). The coenzyme differs from Vitamin B12 by the presence of a 5￠-deoxyadenosyl group in the axial ligand occupied by the cyanide in the vitamin. Structure: Lenhert, Hodgkin,
Nature 192, 937 (1961). The nucleoside is linked to the cobalt via the 5￠-carbon atom of its deoxyribosyl moiety and the biological and chemical reactivity reside in this C to Co bond: Hogenkamp
et al., J. Biol. Chem. 240, 3641 (1965) and
Fed. Proc. 25, 1623 (1966).
Review: Smith,
Vitamin B12 (Methuen & Co., London, 3rd ed., 1965).
Properties: Yellow-orange six-faced crystals which become deep red upon exposure to air. Absorption max (H2O): 260, 375, 522 nm (A ′ 10-6 34.7, 10.9, 8.0 cm2/mole). Soly in water (24°): 16.4 mmol. Solns of pH <3.5 are yellow, >3.5, red. Sol in ethanol, phenol. Practically insol in acetone, ether, dichloroethylene, dioxane. pKa 3.5. Stability studies: Collado, Nieto,
Ann. Pharm. Fr. 27, 427 (1969). Highly sensitive to light, to cyanide and moderately sensitive to acid. Solns are most stable at pH 6-7 stored in the dark. Heating of acid or alkaline solns produces slow inactivation.
pKa: pKa 3.5
Absorption maximum: Absorption max (H2O): 260, 375, 522 nm (A ′ 10-6 34.7, 10.9, 8.0 cm2/mole)
Therap-Cat: Vitamin (hematopoietic).
Therap-Cat-Vet: Vitamin (hematopoietic).
Keywords: Vitamin/Vitamin Source; Vitamin B12.
