Methylcobalamin (mecobalamin, MeCbl, or MeB12) is a cobalamin, a form of vitamin B12. It differs from cyanocobalamin in that the cyano group at the cobalt is replaced with a methyl group.[1] Methylcobalamin features an octahedral cobalt(III) centre and can be obtained as bright red crystals.[2] From the perspective of coordination chemistry, methylcobalamin is notable as a rare example of a compound that contains metal–alkyl bonds. Nickel–methyl intermediates have been proposed for the final step of methanogenesis.
Methylcobalamin is equivalent physiologically to vitamin B12,[3] and can be used to prevent or treat pathology arising from a lack of vitamin B12 intake (vitamin B12 deficiency).
Methylcobalamin that is ingested is not used directly as a cofactor, but is first converted by MMACHC into cob(II)alamin. Cob(II)alamin is then later converted into the other two forms, adenosylcobalamin and methylcobalamin for use as cofactors. That is, methylcobalamin is first dealkylated and then regenerated.[5][6][7]
Methylcobalamin physically resembles the other forms of vitamin B12, occurring as dark red crystals that freely form cherry-colored transparent solutions in water.
Methylcobalamin participates in the Wood-Ljungdahl pathway, which is a pathway by which some organisms utilize carbon dioxide as their source of organic compounds. In this pathway, methylcobalamin provides the methyl group that couples to carbon monoxide (derived from CO2) to afford acetyl-CoA. Acetyl-CoA is a derivative of acetic acid that is converted to more complex molecules as required by the organism.[9]
Methylcobalamin is produced by some bacteria.[citation needed] It plays an important role in the environment, where it is responsible for the biomethylation of certain heavy metals. For example, the highly toxic methylmercury is produced by the action of methylcobalamin.[10] In this role, methylcobalamin serves as a source of "CH3+".
A lack of cobalamin can lead to megaloblastic anemia and subacute combined degeneration of the spinal cord.[11]
^McDowell LR (2000). Vitamins in animal and human nutrition. Wiley. ISBN978-0813826301. Retrieved 28 January 2018 – via Booksgoogle.com.
^ abDavid D (January 1971). "Preparation of the Reduced Forms of Vitamin B12 and of Some Analogs of the Vitamin B12 Coenzyme Containing a Cobalt-Carbon Bond". In McCormick DB, Wright LD (eds.). Vitamins and Coenzymes. Methods in Enzymology. Vol. 18. Academic Press. pp. 34–54. doi:10.1016/S0076-6879(71)18006-8. ISBN9780121818821.
^Sil A, Kumar H, Mondal RD, Anand SS, Ghosal A, Datta A, Sawant SV, Kapatkar V, Kadhe G, Rao S (July 2018). "A randomized, open labeled study comparing the serum levels of cobalamin after three doses of 500 mcg vs. a single dose methylcobalamin of 1500 mcg in patients with peripheral neuropathy". The Korean Journal of Pain. 31 (3): 183–190. doi:10.3344/kjp.2018.31.3.183. PMC6037815. PMID 30013732.
^"Eisai Submits New Drug Application for Mecobalamin Ultra-High Dose Preparation as Treatment for Amyotrophic Lateral Sclerosis in Japan" (PDF). Eisai.com. Retrieved 28 January 2018.
^Kim J, Hannibal L, Gherasim C, Jacobsen DW, Banerjee R (November 2009). "A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins". The Journal of Biological Chemistry. 284 (48): 33418–33424. doi:10.1074/jbc.M109.057877. PMC2785186. PMID 19801555.
^Hannibal L, Kim J, Brasch NE, Wang S, Rosenblatt DS, Banerjee R, Jacobsen DW (August 2009). "Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product". Molecular Genetics and Metabolism. 97 (4): 260–266. doi:10.1016/j.ymgme.2009.04.005. PMC2709701. PMID 19447654.
^Froese DS, Gravel RA (November 2010). "Genetic disorders of vitamin B₁₂ metabolism: eight complementation groups–eight genes". Expert Reviews in Molecular Medicine. 12: e37. doi:10.1017/S1462399410001651. PMC2995210. PMID 21114891.
^Thakkar K, Billa G (January 2015). "Treatment of vitamin B12 deficiency – Methylcobalamine? Cyancobalamine? Hydroxocobalamin? – clearing the confusion". European Journal of Clinical Nutrition. 69 (1): 1–2. doi:10.1038/ejcn.2014.165. PMID 25117994.
^Fontecilla-Camps JC, Amara P, Cavazza C, Nicolet Y, Volbeda A (August 2009). "Structure-function relationships of anaerobic gas-processing metalloenzymes". Nature. 460 (7257): 814–822. Bibcode:2009Natur.460..814F. doi:10.1038/nature08299. PMID 19675641. S2CID 4421420.
^Schneider Z, Stroiński A (1987), Comprehensive B12: Chemistry, Biochemistry, Nutrition, Ecology, Medicine, Walter de Gruyter, ISBN978-3110082395
^Bémeur C, Montgomery JA, Butterworth RF (2011). "Vitamins Deficiencies and Brain Function". In Blass JP (ed.). Neurochemical Mechanisms in Disease. Advances in Neurobiology. Vol. 1. pp. 103-124 (112). doi:10.1007/978-1-4419-7104-3_4. ISBN978-1-4419-7103-6.
January 01, 1970
methylcobalamin, mecobalamin, mecbl, meb12, cobalamin, form, vitamin, differs, from, cyanocobalamin, that, cyano, group, cobalt, replaced, with, methyl, group, features, octahedral, cobalt, centre, obtained, bright, crystals, from, perspective, coordination, c. Methylcobalamin mecobalamin MeCbl or MeB12 is a cobalamin a form of vitamin B12 It differs from cyanocobalamin in that the cyano group at the cobalt is replaced with a methyl group 1 Methylcobalamin features an octahedral cobalt III centre and can be obtained as bright red crystals 2 From the perspective of coordination chemistry methylcobalamin is notable as a rare example of a compound that contains metal alkyl bonds Nickel methyl intermediates have been proposed for the final step of methanogenesis MethylcobalaminClinical dataTrade namesCobolminAHFS Drugs comInternational Drug NamesRoutes ofadministrationBy mouth sublingual injection ATC codeB03BA05 WHO Legal statusLegal statusUS OTCIdentifiersIUPAC name carbanide cobalt 3 CAS Number13422 55 4 YPubChem CID6436232ChemSpider29368587UNIIBR1SN1JS2WChEMBLChEMBL1697757 NCompTox Dashboard EPA DTXSID5048631ECHA InfoCard100 033 200Chemical and physical dataFormulaC 63H 91Co N 13O 14PMolar mass1344 405 g mol 13D model JSmol Interactive imageSMILES CH3 CC1 CC2 C C C1C N C N2 C3C C C O3 CO OP O O OC C CNC O CCC4 C C5C6 C C C N6 C C7C C C N7 C C8C C C N8 C C4 N 5 C CCC O N C C CCC O N C CC O N C CCC O N C CC O N C CC O N C O Co 3 InChI InChI 1S C62H90N13O14P CH3 Co c1 29 20 39 40 21 30 29 2 75 28 70 39 57 52 84 53 41 27 76 87 57 89 90 85 86 88 31 3 26 69 49 83 18 19 59 8 37 22 46 66 80 56 62 11 61 10 25 48 68 82 36 14 17 45 65 79 51 74 62 33 5 55 60 9 24 47 67 81 34 12 15 43 63 77 38 71 55 23 42 58 6 7 35 13 16 44 64 78 50 72 42 32 4 54 59 73 56 h20 21 23 28 31 34 37 41 52 53 56 57 76 84H 12 19 22 24 27H2 1 11H3 H15 63 64 65 66 67 68 69 71 72 73 74 77 78 79 80 81 82 83 85 86 1H3 q 1 3 p 2Key ZFLASALABLFSNM UHFFFAOYSA L N Y what is this verify Methylcobalamin is equivalent physiologically to vitamin B12 3 and can be used to prevent or treat pathology arising from a lack of vitamin B12 intake vitamin B12 deficiency Methylcobalamin is also used in the treatment of peripheral neuropathy diabetic neuropathy and as a preliminary treatment for amyotrophic lateral sclerosis 4 Methylcobalamin that is ingested is not used directly as a cofactor but is first converted by MMACHC into cob II alamin Cob II alamin is then later converted into the other two forms adenosylcobalamin and methylcobalamin for use as cofactors That is methylcobalamin is first dealkylated and then regenerated 5 6 7 According to one author it is important to treat vitamin B12 deficiency with hydroxocobalamin or cyanocobalamin or a combination of adenosylcobalamin and methylcobalamin and not methylcobalamin alone 8 Contents 1 Production 2 Functions 3 See also 4 ReferencesProduction edit nbsp Methylcobalamin physically resembles the other forms of vitamin B12 occurring as dark red crystals that freely form cherry colored transparent solutions in water Methylcobalamin can be produced in the laboratory by reducing cyanocobalamin with sodium borohydride in alkaline solution followed by the addition of methyl iodide 2 Functions editThis vitamer along with adenosylcobalamin is one of two active coenzymes used by vitamin B12 dependent enzymes and is the specific vitamin B12 form used by 5 methyltetrahydrofolate homocysteine methyltransferase MTR also known as methionine synthase citation needed Methylcobalamin participates in the Wood Ljungdahl pathway which is a pathway by which some organisms utilize carbon dioxide as their source of organic compounds In this pathway methylcobalamin provides the methyl group that couples to carbon monoxide derived from CO2 to afford acetyl CoA Acetyl CoA is a derivative of acetic acid that is converted to more complex molecules as required by the organism 9 Methylcobalamin is produced by some bacteria citation needed It plays an important role in the environment where it is responsible for the biomethylation of certain heavy metals For example the highly toxic methylmercury is produced by the action of methylcobalamin 10 In this role methylcobalamin serves as a source of CH3 A lack of cobalamin can lead to megaloblastic anemia and subacute combined degeneration of the spinal cord 11 See also editCobamamide Cyanocobalamin Hydroxocobalamin Vitamin B12 Cobalamin biosynthesisReferences edit McDowell LR 2000 Vitamins in animal and human nutrition Wiley ISBN 978 0813826301 Retrieved 28 January 2018 via Booksgoogle com a b David D January 1971 Preparation of the Reduced Forms of Vitamin B12 and of Some Analogs of the Vitamin B12 Coenzyme Containing a Cobalt Carbon Bond In McCormick DB Wright LD eds Vitamins and Coenzymes Methods in Enzymology Vol 18 Academic Press pp 34 54 doi 10 1016 S0076 6879 71 18006 8 ISBN 9780121818821 Sil A Kumar H Mondal RD Anand SS Ghosal A Datta A Sawant SV Kapatkar V Kadhe G Rao S July 2018 A randomized open labeled study comparing the serum levels of cobalamin after three doses of 500 mcg vs a single dose methylcobalamin of 1500 mcg in patients with peripheral neuropathy The Korean Journal of Pain 31 3 183 190 doi 10 3344 kjp 2018 31 3 183 PMC 6037815 PMID 30013732 Eisai Submits New Drug Application for Mecobalamin Ultra High Dose Preparation as Treatment for Amyotrophic Lateral Sclerosis in Japan PDF Eisai com Retrieved 28 January 2018 Kim J Hannibal L Gherasim C Jacobsen DW Banerjee R November 2009 A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins The Journal of Biological Chemistry 284 48 33418 33424 doi 10 1074 jbc M109 057877 PMC 2785186 PMID 19801555 Hannibal L Kim J Brasch NE Wang S Rosenblatt DS Banerjee R Jacobsen DW August 2009 Processing of alkylcobalamins in mammalian cells A role for the MMACHC cblC gene product Molecular Genetics and Metabolism 97 4 260 266 doi 10 1016 j ymgme 2009 04 005 PMC 2709701 PMID 19447654 Froese DS Gravel RA November 2010 Genetic disorders of vitamin B metabolism eight complementation groups eight genes Expert Reviews in Molecular Medicine 12 e37 doi 10 1017 S1462399410001651 PMC 2995210 PMID 21114891 Thakkar K Billa G January 2015 Treatment of vitamin B12 deficiency Methylcobalamine Cyancobalamine Hydroxocobalamin clearing the confusion European Journal of Clinical Nutrition 69 1 1 2 doi 10 1038 ejcn 2014 165 PMID 25117994 Fontecilla Camps JC Amara P Cavazza C Nicolet Y Volbeda A August 2009 Structure function relationships of anaerobic gas processing metalloenzymes Nature 460 7257 814 822 Bibcode 2009Natur 460 814F doi 10 1038 nature08299 PMID 19675641 S2CID 4421420 Schneider Z Stroinski A 1987 Comprehensive B12 Chemistry Biochemistry Nutrition Ecology Medicine Walter de Gruyter ISBN 978 3110082395 Bemeur C Montgomery JA Butterworth RF 2011 Vitamins Deficiencies and Brain Function In Blass JP ed Neurochemical Mechanisms in Disease Advances in Neurobiology Vol 1 pp 103 124 112 doi 10 1007 978 1 4419 7104 3 4 ISBN 978 1 4419 7103 6 Retrieved from https en wikipedia org w index php title Methylcobalamin amp oldid 1198360116, wikipedia, wiki, book, books, library,
