5-Methyltetrahydrofolate

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Nicolle Breusing - One of the best experts on this subject based on the ideXlab platform.

Michael Rychlik - One of the best experts on this subject based on the ideXlab platform.

  • Stability of 5-Methyltetrahydrofolate in fortified apple and carrot purées
    LWT, 2019
    Co-Authors: Anna-lena Herbig, Nicolas Delchier, Lisa Striegel, Michael Rychlik, Catherine M.g.c. Renard
    Abstract:

    Abstract 5-Methyltetrahydrofolate, the naturally abundant folate vitamer, has been proposed as an alternative to folic acid for fortification. However, it is less stable than folic acid. In a formate buffer (pH 3.5), folic acid was entirely preserved after heating the solution for 3 h at 80 °C. In contrast, 5-Methyltetrahydrofolate was completely degraded in less than 15 min. As in the buffer, 5-Methyltetrahydrofolate in apple or carrot purees degraded rapidly without the addition of ascorbic acid. By adding ascorbic acid, the stability could be increased, but the chosen amount was crucial. An excess of vitamin C compared to 5-Methyltetrahydrofolate was not always sufficient for the complete protection of 5-Methyltetrahydrofolate during 3 h at 80 °C. Only by adding 2840 μmol/kg of ascorbic acid (equivalent to 500 mg/kg), 5-Methyltetrahydrofolate seemed to remain stable. Degradation started after approximately 60 min when 570 μmol/kg of ascorbic acid (equivalent to 100 mg/kg) were added; after 120 min with 1420 μmol/kg (equivalent to 250 mg/kg). In addition, a temperature decrease to 70 °C or 60 °C did not increase the stability of 5-Methyltetrahydrofolate.

  • Stability of 5-Methyltetrahydrofolate in fortified apple and carrot purées
    LWT - Food Science and Technology, 2019
    Co-Authors: Anna-lena Herbig, Nicolas Delchier, Lisa Striegel, Michael Rychlik, Catherine Renard
    Abstract:

    5-Methyltetrahydrofolate, the naturally abundant folate vitamer, has been proposed as an alternative to folic acid for fortification. However, it is less stable than folic acid. In a formate buffer (pH 3.5), folic acid was entirely preserved after heating the solution for 3 h at 80 °C. In contrast, 5-Methyltetrahydrofolate was completely degraded in less than 15 min. As in the buffer, 5-Methyltetrahydrofolate in apple or carrot purées degraded rapidly without the addition of ascorbic acid. By adding ascorbic acid, the stability could be increased, but the chosen amount was crucial. An excess of vitamin C compared to 5-Methyltetrahydrofolate was not always sufficient for the complete protection of 5-Methyltetrahydrofolate during 3 h at 80 °C. Only by adding 2840 μmol/kg of ascorbic acid (equivalent to 500 mg/kg), 5-Methyltetrahydrofolate seemed to remain stable. Degradation started after approximately 60 min when 570 μmol/kg of ascorbic acid (equivalent to 100 mg/kg) were added; after 120 min with 1420 μmol/kg (equivalent to 250 mg/kg). In addition, a temperature decrease to 70 °C or 60 °C did not increase the stability of 5-Methyltetrahydrofolate.

  • Study design.
    2019
    Co-Authors: Lisa Striegel, Beate Brandl, Markus Kopp, Lukas Sam, Thomas Skurk, Michael Rychlik
    Abstract:

    Overview of the timeline and the different blood sampling time points for one of the three interventions. Details are described in the text. 5-CH3-H4folate, 5-Methyltetrahydrofolate; STD, standardized.

  • Simulation of Food Folate Digestion and Bioavailability of an Oxidation Product of 5-Methyltetrahydrofolate
    Nutrients, 2017
    Co-Authors: Christiane Ringling, Michael Rychlik
    Abstract:

    Generating bioavailability data from in vivo studies is time-consuming and expensive. In vitro simulation can help to investigate factors influencing bioavailability or facilitate quantifying the impact of such factors. For folates, an efficient deconjugation of polyglutamates to the corresponding monoglutamates is crucial for bioavailability and highly dependent on the food matrix. Therefore, the bioaccessibility of folates of different foodstuffs was examined using a simulated digestion model with respect to folate stability and the efficiency of deconjugation. For realistic simulated deconjugation, porcine brush border membrane was used during the phase of the simulated digestion in the small intestine. For a better understanding of folate behaviour during digestion, single folate monoglutamates were also investigated with this in vitro digestion model. The results for bioaccessibility were compared with data from a human bioavailability study. They support the idea that both stability and deconjugation have an influence on bioaccessibility and thus on bioavailability. Tetrahydrofolate is probably lost completely or at least to a high extent and the stability of 5-Methyltetrahydrofolate depends on the food matrix. Additionally, 5-Methyltetrahydrofolate can be oxidised to a pyrazino-s-triazine (MeFox), whose absorption in the human intestinal tract was shown tentatively.

  • Measurements of Intra- and Extra-Cellular 5-Methyltetrahydrofolate Indicate that Bifidobacterium Adolescentis DSM 20083T and Bifidobacterium Pseudocatenulatum DSM 20438T Do Not Actively Excrete 5-Methyltetrahydrofolate In vitro
    Frontiers in Microbiology, 2017
    Co-Authors: Markus Kopp, Kerstin Dürr, Matthias Steigleder, Thomas Clavel, Michael Rychlik
    Abstract:

    Certain intestinal bifidobacteria have the ability to synthesize folates. In vitro experiments revealed a high production, cellular accumulation, and release of reduced folate vitamers like 5-Methyltetrahydrofolate and tetrahydrofolate in folate-free medium (FFM). However, it is still unclear to which extent synthesized folates are polyglutamylated and probably not available for transport, and if they are actively released by excretion. To address these questions, we characterized intra- and extracellular pteroylmonoglutamates and polyglutamylated 5-Methyltetrahydrofolate (5-CH3-H4PteGlu2-4) in B. adolescentis DSM 20083T and B. pseudocatenulatum DSM 20438T in vitro. Folates were measured by means of stable isotope dilution assays coupled with LC-MS/MS analysis using [2H4]-5-methyltetrahydrofolic acid, [2H4]-tetrahydrofolic acid and [2H4]-5-formyltetrahydrofolic acid as internal standards. Cell viability was examined by fluorescence microscopy. Quantitation of folate production by B. adolescentis during the stationary phase revealed a linear increase of dead cells paralleled by increasing concentration of 5-formyltetrahydrofolate and 5-Methyltetrahydrofolate (100% 5-CH3-H4PteGlu4) in FFM, whereas the intracellular concentrations of these vitamers remained constant. After 24 h, B. adolescentis (125 mg cells, wet weight) produced a total amount of 0.846 nmol 5-CH3-H4folate: 0.385±0.059 nmol (46±7%) and 0.461±0.095 nmol (54±11%) measured in the intracellular (viable cells; 52±3% measured by fluorescence microscopy) and extracellular (lysed cells; 48±3%) fraction, respectively. For B. pseudocatenulatum (124 mg cells, wet weight), 1.135 nmol 5-CH3-H4folate was produced after 24 h, and a similar proportionality between intra/extracellular folate concentrations and viable/lysed cells was observed. These results indicate that the strains tested produce and accumulate 5-CH3-H4PteGlu4 for cellular metabolism, and that extracellular concentrations of the vitamer arise from cell lysis.

Daniela Weber - One of the best experts on this subject based on the ideXlab platform.

Wolfgang Bernhard - One of the best experts on this subject based on the ideXlab platform.

Wolfgang Stuetz - One of the best experts on this subject based on the ideXlab platform.