Hydroxocobalamin

Title: Hydroxocobalamin
CAS Registry Number: 13422-51-0
CAS Name: Cobinamide hydroxide dihydrogen phosphate (ester) inner salt 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1H-benzimidazole
Additional Names: a-(5,6-dimethylbenzimidazolyl)hydroxocobamide; vitamin B12a; hydroxocobemine; OHB12
Trademarks: Cobalin-H (Link); Dodécavit (Serb); Duradoce (Atlantis); Neo-Cytamen (Medeva); Redisol H (Merck & Co.)
Molecular Formula: C62H89CoN13O15P
Molecular Weight: 1346.36
Percent Composition: C 55.31%, H 6.66%, Co 4.38%, N 13.52%, O 17.83%, P 2.30%
Literature References: Physiological analog of vitamin B12 where the CN group is replaced with OH. Exists in aq soln as an equilibrium mixture of the hydroxy isomer and the ionic aqua isomer (aquacobalamin). Precursor of the coenzymes methylcobalamin and cobamamide, q.q.v. Prepn: E. A. Kaczka et al., J. Am. Chem. Soc. 71, 1514 (1949); eidem, ibid. 73, 335 (1951); eidem, US 2738301 (1956 to Merck & Co.). Acids replace the hydroxo group with the anion of the acid: eidem, Science 112, 354 (1950). Prepn from cyanocobalamin: R. Bieganowski, G. Klar, Chem. Ztg. 106, 235 (1982). Clinical evaluation as antidote to cyanide: J. C. Forsyth et al., Clin. Toxicol. 31, 277 (1993). Review: "Vitamin B12" in Vitamins, W. Friedrich, Ed. (de Gruyter, Berlin, 1988) pp 837-928.
Properties: Dark red, orthorhombic needles or platelets from water + acetone. Darkens at 200°, but not melted at 300°. Absorption max (H2O): 279, 325, 359, 516, 537 nm (e 19000, 11400, 20600, 8900, 9500). Moderately sol in water and in the lower aliphatic alcohols. Practically insol in acetone, ether, petr ether, halogenated hydrocarbons, benzene.
Absorption maximum: Absorption max (H2O): 279, 325, 359, 516, 537 nm (e 19000, 11400, 20600, 8900, 9500)
Derivative Type: Aquacobalamin
CAS Registry Number: 13422-52-1
CAS Name: Cobinamide hydroxide monohydrate dihydrogen phosphate (ester) inner salt 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1H-benzimidazole
Additional Names: aquocobalamin; vitamin B12b; vitamin B12d
Molecular Formula: C62H90CoN13O15P.OH
Molecular Weight: 1364.37
Percent Composition: C 54.58%, H 6.72%, Co 4.32%, N 13.35%, O 18.76%, P 2.27%
Properties: Absorption max (H2O): 274, 317, 351, 499, 527 nm (e 20600, 6100, 26500, 8100, 8500).
Absorption maximum: Absorption max (H2O): 274, 317, 351, 499, 527 nm (e 20600, 6100, 26500, 8100, 8500)
Derivative Type: Acetatocobalamin
CAS Registry Number: 22465-48-1
Additional Names: Cobinamide acetate (salt) dihydrogen phosphate (ester) inner salt 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1H-benzimidazole
Trademarks: Depogamma (Woerwag); Docelan (Aventis); Novidroxin (Fatol)
Molecular Formula: C64H91CoN13O16P
Molecular Weight: 1388.39
Percent Composition: C 55.37%, H 6.61%, Co 4.24%, N 13.11%, O 18.44%, P 2.23%
Literature References: Prepn of stable solns: Marcus et al., FR 1336671 (1963 to Merck & Co.), C.A. 60, 380a (1964).
Derivative Type: Nitrocobalamin
CAS Registry Number: 20623-13-6
CAS Name: Cobinamide nitrite (salt) dihydrogen phosphate (ester) inner salt 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1H-benzimidazole
Additional Names: nitritocobalamin; vitamin B12c
Molecular Formula: C62H88CoN14O16P
Molecular Weight: 1375.35
Percent Composition: C 54.14%, H 6.45%, Co 4.28%, N 14.26%, O 18.61%, P 2.25%
Literature References: Prepn: E. A. Kaczka et al., J. Am. Chem. Soc. 73, 3569 (1951).
Properties: Red crystalline solid. Absorption max in water: 352, 527.5 nm (E1%1cm 153.2, 59.5); in 0.01N NaOH: 357, 535 nm (E1%1cm 139, 62.5).
Absorption maximum: Absorption max in water: 352, 527.5 nm (E1%1cm 153.2, 59.5); in 0.01N NaOH: 357, 535 nm (E1%1cm 139, 62.5)
Derivative Type: Sulfitocobalamin
CAS Registry Number: 15671-27-9
CAS Name: Cobinamide sulfite (1:1) (salt) dihydrogen phosphate (ester) inner salt 3¢-ester with 5,6-dimethyl-1-a-D-ribofuranosyl-1H-benzimidazole
Additional Names: cobalaminsulfonic acid
Molecular Formula: C62H89CoN13O17PS
Molecular Weight: 1410.42
Percent Composition: C 52.80%, H 6.36%, Co 4.18%, N 12.91%, O 19.28%, P 2.20%, S 2.27%
Literature References: Prepn: Fricke, US 2721162 (1955 to Abbott).
Properties: Absorption max: 275, 365, 418, 516 nm (E1%1cm 328, 130, 49, 61).
Absorption maximum: Absorption max: 275, 365, 418, 516 nm (E1%1cm 328, 130, 49, 61)
Therap-Cat: Vitamin (hematopoietic).
Therap-Cat-Vet: Vitamin (hematopoietic).
Keywords: Vitamin/Vitamin Source; Vitamin B12.
Hydroxyamphetamine Hydroxychloroquine Hydroxycodeinone Hydroxydione Sodium Hydroxyglutamic Acid

Hydroxocobalamin
Hydroxocobalamin.svg
Hydroxocobalamin ball-and-stick animation.gif
Systematic (IUPAC) name
Coα-[α-(5,6-dimethylbenzimidazolyl)]-
Coβ-hydroxocobamide
Clinical data
AHFS/Drugs.com Consumer Drug Information
MedlinePlus a605007
Pregnancy cat. C (US)[1]
Legal status OTC (US) Prescription injectable in U.S. Not DEA-controlled
Routes Injectable (intramuscular, intravenous, or subcutaneous)
Pharmacokinetic data
Protein binding Very high (90%)
Metabolism Primarily hepatic, cobalamins are absorbed in the ileum and stored in the liver.
Half-life ~6 days
Identifiers
CAS number 13422-51-0 YesY
ATC code B03BA03 V03AB33
PubChem CID 6433575
DrugBank DB00200
ChemSpider 21160115 YesY
UNII Q40X8H422O YesY
KEGG D01027 YesY
ChEMBL [2] CHEMBL1237097[2] N
Chemical data
Formula C62H89CoN13O15P 
Mol. mass 1346.37 g/mol
 N (what is this?)  (verify)
Hydroxocobalamin injection USP (1000 mcg/mL) is a clear red liquid solution of hydoxocobalamin which is available in a 30 mL brown glass multidose vial packaged in a paper box. Shown is 500 mcg B-12 (as 1/2 cc) drawn up in a 1/2 cc U-100 27 gauge x 1/2" insulin syringe, as prepared for subcutaneous injection.

Hydroxocobalamin (OHCbl, or B12a) is a natural form, or vitamer, of vitamin B12, a basic member of the cobalamin family of compounds. Hydroxocobalamin is the form of vitamin B12 produced by many bacteria which are used to produce the vitamin commercially. Like other forms of vitamin B12, hydroxocobalamin has an intense red color. It is not a form normally found in the human body, but is easily converted in the body to usable coenzyme forms of vitamin B12. Pharmaceutically, hydroxocobalamin is usually produced as a sterile injectable solution and is used for treatment of the vitamin deficiency, and also (because of its affinity for cyanide ion) as a treatment for cyanide poisoning.[3] It has been experimentally tested as a scavenger of nitric oxide.

"Vitamin B12" refers to a group of compounds called cobalamins that are available in the human body in a variety of mostly interconvertible forms. Together with folic acid, cobalamins are essential cofactors required for DNA synthesis in cells where chromosomal replication and division are occurring—most notably the bone marrow and myeloid cells. As a cofactor, cobalamins are essential for two cellular reactions:

  • the mitochondrial methylmalonyl-CoA mutase conversion of methylmalonic acid (MMA) to succinate, which links lipid and carbohydrate metabolism, and
  • the activation of methionine synthasee, which is the rate-limiting step in the synthesis of methionine from homocysteine and 5-methyltetrahydrofolate.