Vitamin B12

Wijmenga, H. G.; Veer, W. L. C.; Lens, J

doi:10.1016/0006-3002(50)90096-5

Cited by 50 publications

(8 citation statements)

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“…The photolysis of vitamin Bn on exposure to visible light with the formation of vitamin Bnb has also been observed by these authors. The conversion of vitamins B12a and Bi2b to vitamin Bn (cyanocobalamin) by addition of cyanide ions has been observed (105,197). The formation of a purple blue color in vitamin B12 solutions containing excess potassium cyanide has likewise been reported (176,197,204).…”

Section: Vitaminsmentioning

confidence: 96%

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Pharmaceuticals and Natural Drugs

Marsh¹,

Hilty²

1952

Anal. Chem.

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AS IS the case in all the major fields of the science, the litera-_ \_ ture pertaining to analytical chemistry is rapidly approaching a state of practical unwieldiness. One might say-and not too facetiously-that a detailed search of published information for an analytical project in applied analysis could conceivably involve a large proportion of the time devoted to the project itself. The number of annual published contributions to analytical studies of pharmaceutical and natural drugs alone is estimated to be nearly a thousand.The preparation of a review covering such a number and diversity of publications necessarily poses several problems. Foremost among these is the matter of selection of material, since it is obvious that an abstract of the contents of each article could not be included. The authors wish to repeat and to re-emphasize the fact that omissions from the review do not imply that the papers so omitted do not contain useful information. A conscious effort has been made, however, to include those studies and procedures which offer the greatest possibilities for use in pharmaceutical analysis.The classification of methods is the same as that published in the previous annual reviews of pharmaceuticals and natural drugs.

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Section: Vitaminsmentioning

confidence: 96%

“…The conversion of vitamins B12a and Bi2b to vitamin Bn (cyanocobalamin) by addition of cyanide ions has been observed (105,197). The formation of a purple blue color in vitamin B12 solutions containing excess potassium cyanide has likewise been reported (176,197,204).…”

Section: Vitaminsmentioning

confidence: 96%

Pharmaceuticals and Natural Drugs

Marsh¹,

Hilty²

1952

Anal. Chem.

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“…This chemical group is only present in the structure of synthetic preparations of vitamin B 12 , that is it is not naturally synthetized, and it can also be originated as a result of the extraction procedure by which the compound is removed from bacterial cultures (Martens et al, 2002). It was observed at Organon in the Netherlands, in 1950, that cyanocobalamin is the most chemically stable form of vitamin B 12 (Wijmenga, Veer, & Lens, 1950). This was a result of experiments in which a treatment of vitamin B 12 with KCN was performed, promoting the replacement of the upper ligand present in biologically active forms by a cyano.…”

Section: Chemical Structurementioning

confidence: 99%

Microalgal assimilation of vitamin B₁₂toward the production of a superfood

Pereirã

Simões

Silva³

2019

J Food Biochem

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A network of components from different metabolic pathways is the building scaffold of an indispensable compound in the human organism—vitamin B12. The biosynthesis of this compound is restricted to a limited number of representatives of bacteria and archaea, while vitamin B12‐dependent enzymes are spread through several domains of life. Different attempts have been performed to increase vitamin B12 levels in dietary products, particularly in vegetarian and vegan dietary regimes. The integration of vitamin B12 in microalgae through symbiosis with microorganisms generally recognized as safe, for example the probiotic Lactobacillus reuteri, can even increase the nutritional value of the microalgal biomass. This study reviews the microbial production of vitamin B12 based on genetic analyses and chemical studies. Recent genetic approaches are focused, particularly potential metabolic engineering targets to increase vitamin B12 production. The bioincorporation of vitamin B12 in microalgae as an attempt to provide a superfood is also reviewed. Practical applications Novel food habits (i.e., vegan lifestyle) may lack relevant nutrients, including vitamin B12. Therefore, there is an increased demand for dietary products rich in vitamin B12. Of potential interest is the provision of microbial‐based superfood rich in numerous nutrients, including this vitamin. This manuscript provides an in‐depth and timely overview on vitamin B12 biosynthesis and the major advances on metabolic engineering for improved vitamin B12 production by probiotic bacteria and other microorganisms generally recognized as safe. A relevant advance would result from the bioincorporation of vitamin B12 in alternative microorganisms (non‐vitamin B12 producers) increasingly recognized as superfood, that is microalgae.

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“…(OH-B12) was isolated by Pierce et al (l) in a crystalline form from the culture of Streptoinyces aureofaciens and was designated as vitamin B12b, which was soon ascertained to be the same as B12a obtainable by catalytic reduction of cyanocobalamin (CN-B12) using platinum as a catalyst (3,4). It was also found that OH-B12 was formed by irradiation of CN-B12 in an acidic solution and that it was converted to CN-B12 by treatment with cyanide in a neutral medium (5).…”

Section: Hydroxocobalaminmentioning

confidence: 99%