Antivitamin B12 activity for the growing chick and developing chick embryo of some analogs of cyanocobalamin

Coates, Michael I.; Davies, M. K.; Harrison, G. F.

doi:10.1016/0003-9861(60)90128-4

Cited by 22 publications

(9 citation statements)

References 6 publications

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“…The relative antagonistic activity was tested after a prolonged period of incubation (72 hr) ; under these conditions the anilide was a more active analogue than the ethylamide. A similar order of activities has been found for the growing chick (Coates, Davies & Harrison, 1960). The two amides have a reversed order of activities towards 0. malhamensis and E. coli (Ford, 1959;Baker et al 1960;Smith, 1960).…”

Section: Discussionsupporting

confidence: 77%

Nutrition and Vitamin B12 Metabolism of a Soil Bacterium

Aronovitch¹,

Grossowicz²

1968

Journal of General Microbiology

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S U M M A R YThe growth requirements of a vitamin B12-dependent soil bacterium (strain 544), provisionally classified as belonging to the genus Arthvobacter, were studied. The organism showed a high specificity for vitamin B12; of the naturally occurring analogues tested, only a-( 5-hydroxybenzimidazo1y1)-cobamide cyanide and a-(2-methylmercaptoadenyl)cobamide cyanide possessed some growth-promoting activity (less than 10 yo). The anilide and the ethylamide of the monocarboxylic acid of vitamin B12 inhibited growth and the inhibition was reversed by the vitamin. A medium and a procedure for vitamin B12 assay using strain 544, is described. Comparative assays withOchromonas malharnensis and Escherichia coli 7~ are given and their differential usefulness for differentiating the various congeners of vitamin B12 discussed.Addition of vitamin B12 to B12-deficient cell suspensions of strain 544 stimulated the biosynthesis of methionine and the oxidation of propionate, valerate, isoleucine and valine. The endogenous respiration and oxidation of glucose, butyrate, leucine and lysine were only slightly enhanced by vitamin B12.

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Section: Discussionsupporting

confidence: 77%

Nutrition and Vitamin B12 Metabolism of a Soil Bacterium

Aronovitch¹,

Grossowicz²

1968

Journal of General Microbiology

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“…The presence of these mechanisms supports the concept that Cbl analogues of microorganismal origin are inert (1,6,7) or even toxic (7) for animals.…”

Section: Introductionsupporting

confidence: 67%

Presence and formation of cobalamin analogues in multivitamin-mineral pills.

Kondo¹,

Binder²,

Kolhouse³

et al. 1982

J. Clin. Invest.

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A B S T R A C T Because the origin of cobalamin (vitamin B12) analogues in animal chows and animal and human blood and tissues is unknown, we investigated the possibility that multivitamin interactions might convert cobalamin to cobalamin analogues. We homogenized three popular multivitamin-mineral pills in water, incubated them at 37°C for 2 h, and isolated the cobalamin. Using paper chromatography we observed that 20-90% of the cobalamin was present as cobalamin analogues. Studies using cobalamin showed that these analogues were formed due to the concerted action of vitamin C, thiamine, and copper on CN-cobalamin. These cobalamin analogues are absorbed from the gastrointestinal tract of mice and either fail to stimulate or actually inhibit cobalamindependent enzymes when injected parenterally.We conclude that CN-cobalamin can be converted to potentially harmful cobalamin analogues by multivitamin-mineral interactions and that these interactions may be responsible for the presence of cobalamin analogues in animal chows and animal and human blood and tissues.

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“…As more than 90 correlation analyses were made, only p values < 0.02 were considered to be significant. Table 1 [25,26]. One hypothesis is that analogues occupy and block the binding sites for coenzymatic Bn function.…”

Section: Statisticsmentioning

confidence: 99%

Vitamin B<sub>12</sub> Analogues, Homocysteine, Methylmalonic Acid, and Transcobalamins in the Study of Vitamin B<sub>12</sub> Deficiency in Primary Degenerative Dementia

Regland¹,

Abrahamsson

Gottfries³

et al. 1990

Dement Geriatr Cogn Disord

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B₁₂ analogues, homocysteine, methylmalonic acid (MMA), and unsaturated transcobalamins, all potential markers of vitamin B₁₂ status, were analyzed in blood and cerebrospinal fluid (CSF) from 22 patients with primary degenerative dementia of Alzheimer type. The level of active vitamin B12 in serum correlated significantly with serum homocysteine, serum MMA, and CSF homocysteine. CSF B₁₂ correlated significantly with serum homocysteine and serum MMA. The ratio of analogues and active vitamin B₁₂ concentrations in serum (analogue/active B₁₂ ratio) correlated significantly with serum homocysteine, serum MMA and CSF B₁₂. This study had no control group. However, based on available reference values, high concentrations of homocysteine and MMA in serum and unsaturated transcobalamin II in plasma were interpreted as evidence of vitamin B₁₂ depletion or deficiency. Such high concentrations were found in a significant number of patients. In 9 patients, vitamin B₁₂ injections were administered. After treatment, serum homocysteine levels fell significantly. We conclude that vitamin B₁₂ analogues, homocysteine, MMA, and transcobalamins may be useful as markers in studies aimed at clarifying the role of vitamin B12 deficiency in dementia disorders.

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Antivitamin B12 activity for the growing chick and developing chick embryo of some analogs of cyanocobalamin

Cited by 22 publications

References 6 publications

Nutrition and Vitamin B12 Metabolism of a Soil Bacterium

Nutrition and Vitamin B12 Metabolism of a Soil Bacterium

Presence and formation of cobalamin analogues in multivitamin-mineral pills.

Vitamin B<sub>12</sub> Analogues, Homocysteine, Methylmalonic Acid, and Transcobalamins in the Study of Vitamin B<sub>12</sub> Deficiency in Primary Degenerative Dementia

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