Stabilization of Vitamin B12 I

Zuck, D.A.; Conine, James W.

doi:10.1002/jps.2600520112

Cited by 11 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the assay data on the degradation of B 12 and B 12b were subjected to kinetic treatment, and it was found that these vitamins degrade by an apparent first-order kinetics in the presence of AH 2 . This is in agreement with the previous observations that the chemical degradation of B 12 and B 12b follows first-order kinetics (34)(35)(36). The apparent first-order rate constants (k obs ) for the degradation of B 12 and B 12b are given in Table III (28,46), but no comparison of the kinetic data in these reactions has been made.…”

Section: Kinetics Of Degradation Of B 12 and B 12bsupporting

confidence: 89%

See 1 more Smart Citation

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

et al. 2014

View full text Add to dashboard Cite

Abstract. The degradation kinetics of 5×10−5 M cyanocobalamin (B 12 ) and hydroxocobalamin (B 12b ) in the presence of ascorbic acid (AH 2 ) was studied in the pH range of 1. , respectively, indicating a greater effect of AH 2 on B 12b compared to that of B 12 . The k obs -pH profiles for both B 12 and B 12b show the highest rates of degradation around pH 5. The degradation of B 12 and B 12b by AH 2 is affected by the catalytic effect of phosphate ions on the oxidation of AH 2 in the pH range 6.0-8.0.

show abstract

Section: Kinetics Of Degradation Of B 12 and B 12bsupporting

confidence: 89%

“…3,3-Dimethyl-2,5-dioxopyrrolidine-4-propionamide and 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acid have been identified as the oxidation products of B 12 (33). The chemical (34)(35)(36) and photodegradation (21,37) of B 12 and B 12b has been reported to follow first-order kinetics.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Most stabilization methods focus on methods to reduce the formation of hydroxocobalamin, produced by both oxidizing agents and exposure to light. Although there are many suggested additives that can stabilize cyanocobalamin, (see Macek, 1960;Kirschbaum, 1981 for comprehensive lists), the most recognized are ferric salts (e.g., FeCl 3 and saccharated iron oxide) (Macek, 1960;Newmark, 1958;Skeggs, 1952), phosphate buffer (Monajjemzadeh et al, 2014), and potassium ferrocyanide (Zuck & Conine, 1963). A considerably novel method for minimizing the cyano-to-hydroxocobalamin conversion is the application of red light filters in the working laboratory, to filter out the lower wavelengths of light (<600 nm) that contribute most to this reaction (Du et al, 2018).…”

Section: Stabilizationmentioning

confidence: 99%

Vitamins in cell culture media: Stability and stabilization strategies

Schnellbaecher

Binder

Bellmaine

et al. 2019

Biotech & Bioengineering

View full text Add to dashboard Cite

Nowadays, chemically defined cell culture media (CCM) have replaced serum‐ and hydrolysate‐based media that rely on complex ingredients, such as yeast extracts or peptones. Benefits include a significantly lower lot‐to‐lot variability, more efficient manufacturing by reduction to essential components, and the ability to exclude components that may negatively influence growth, viability, or productivity. Even though current chemically defined CCMs provide an excellent basis for various mammalian biotechnological processes, vitamin instabilities are known to be a key factor contributing to the variabilities still present in liquid CCM as well as to short storage times. In this review, the chemical degradation pathways and products for the most relevant vitamins for CCM will be discussed, with a focus on the effects of light, oxygen, heat, and other CCM compounds. Different approaches to stabilize vitamins in solution, such as replacement with analogs, encapsulation, or the addition of stabilizing compounds will also be reviewed. While these vitamins and vitamin stabilization approaches are presented here as particular for CCM, the application of these concepts can also be considered relevant for pharmaceutical, medical, and food supplement purposes. More precise knowledge regarding vitamin instabilities will contribute to stabilize future formulations and thus decrease residual lot‐to‐lot variability.

show abstract

Destruction of Vitamin B12 by Ascorbic Acid

Herbert¹

1974

JAMA

View full text Add to dashboard Cite

\s=b\ High doses of vitamin C, popularly used as a home remedy against the common cold, destroy substantial amounts of vitamin B when ingested with food. Because this undesirable effect is unequivocal when measured in vitro, while the value of ascorbic acid in preventing the common cold is highly equivocal, daily ingestion of 0.5 gm or more of ascorbic acid without regular evaluation of vitamin B12 status is probably unwise. (JAMA 230:241-242, 1974) PAULING12 has suggested that amounts of ascorbic acid in the gram range be taken daily as protection against the common cold. Recent studies3,4 suggest that such doses do not prevent the appearance of the common cold, but do reduce symp¬ toms of each individual cold. Despite possible adverse effects of large doses of ascorbate5 "the public literally swallowed it whole, and sales of vita¬ min C have remained healthily high ever since" (Newsweek, Jan 21,1974, p 56).Recently, we observed6 that four of nine paraplegic veterans taking 1 gm of ascorbic acid daily by prescription to keep their urine acid (since the an¬ tibiotic they were taking was most effective at acid pH), had low serum vitamin B12 levels. Preliminary stud¬ ies suggested that these low levels were partly an artifact related to the radioassay procedure employed.7 However, prior studies showed that ascorbate also reduces serum vitamin B12 as measured microbiologically.8 Additionally, a destructive effect of ascorbate on crystalline vitamin B12 was reported two decades ago,9 and reduced (monovalent cobalt) vitamin B12 is less stable than oxidized (trivalent cobalt) vitamin Bl2.lou For these reasons, we investigated the effect of 0.1-, 0.25-, and 0.5-gm doses of ascorbic acid on the vitamin B12 content of meals served at the Bronx Veterans Administration Hos¬ pital. Materials and MethodsTo mimic most closely the situation in which an individual eats a meal and then takes a tablet of ascorbic acid, the following protocol was adopted.Two sets of four identical meals of each menu to be studied were set up on trays as if for delivery to individ¬ ual patients. The food content of each tray was poured into a 1-gal (4-liter) food blender and homogenized for five minutes to mimic both the masti¬ cation of food by the teeth and the further homogenization that occurs in the stomach. Each pair of sample meals was then allowed to incubate for 30 minutes at 37 C to mimic the gastric environment, after addition of 0.1 gm of ascorbic acid to sample 2, 0.25 gm to sample 3, and 0.5 gm to sample 4. After incubation, vitamin B12 content was determined by radio-assay1213 against a series of intrinsic factor concentrate standards to which had been added sufficient ascorbic acid to equal the amount in the as¬ sayed aliquots of each meal, to correct for any artifact effect of ascorbate on vitamin B12 radioassay.7The "modest vitamin B12-content meal" consisted of 177 ml of cream of potato soup; a fruit plate of 100 gm of cottage cheese, 10 gm of lettuce, and 360 gm of canned peaches; 6 gm of crackers; 25 gm of bread; 5 gm of but¬...

show abstract

Stabilization of Vitamin B12 I

Cited by 11 publications

References 3 publications

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

Vitamins in cell culture media: Stability and stabilization strategies

Destruction of Vitamin B12 by Ascorbic Acid

Contact Info

Product

Resources

About