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Montoya-Arroyo A, Brand V, Kröpfl A, Vetter W, Frank J. Metabolism of 11'-α- and 11'-γ-Tocomonoenols in HepG2 Cells Favors the γ-Congener and Results Predominantly in Carboxymethylbutyl-Hydroxychromans. Mol Nutr Food Res 2024; 68:e2300657. [PMID: 38698718 DOI: 10.1002/mnfr.202300657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 03/22/2024] [Indexed: 05/05/2024]
Abstract
SCOPE Tocomonoenols (T1) are little-known vitamin E derivatives naturally occurring in foods. Limited knowledge exists regarding the cellular uptake and metabolism of α-tocomonoenol (αT1) and none about that of γ-tocomonoenol (γT1). METHODS AND RESULTS The study investigates the cytotoxicity, uptake, and metabolism of αT1 and γT1 in HepG2 cells compared to the α- and γ-tocopherols (T) and -tocotrienols (T3). None of the studied tocochromanols are cytotoxic up to 100 µmol L-1. The uptake of the γ-congeners is significantly higher than that of the corresponding α-forms, whereas no significant differences are observed based on the degree of saturation of the sidechain. Carboxymethylbutyl-hydroxychromans (CMBHC) are the predominant short-chain metabolites of all tocochromanols and conversion is higher for γT1 than αT1 as well as for the γ-congeners of T and T3. The rate of metabolism increases with the number of double bonds in the sidechain. The rate of metabolic conversion of the T1 is more similar to tocopherols than to that of the tocotrienols. CONCLUSION This is the first evidence that both αT1 and γT1 follow the same sidechain degradation pathway and exert similar rates of metabolism than tocopherols. Therefore, investigation into the biological activities of tocomonoenols is warranted.
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Affiliation(s)
- Alexander Montoya-Arroyo
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
| | - Viola Brand
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
| | - Alexander Kröpfl
- Department of Food Chemistry (170b), Institute of Food Chemistry, University of Hohenheim, 70599, Stuttgart, Germany
| | - Walter Vetter
- Department of Food Chemistry (170b), Institute of Food Chemistry, University of Hohenheim, 70599, Stuttgart, Germany
| | - Jan Frank
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
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Montoya‐Arroyo A, Muñoz‐González A, Lehnert K, Frick K, Schmid‐Staiger U, Vetter W, Frank J. Monodopsis subterranea is a source of α-tocomonoenol, and its concentration, in contrast to α-tocopherol, is not affected by nitrogen depletion. Food Sci Nutr 2024; 12:1869-1879. [PMID: 38455160 PMCID: PMC10916641 DOI: 10.1002/fsn3.3880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 03/09/2024] Open
Abstract
α-Tomonoenols (αT1) are tocochromanols structurally related to tocopherols (T) and tocotrienols (T3), the bioactive members of the vitamin E family. However, limited evidence exists regarding the sources and biosynthesis of tocomonoenols. Nitrogen depletion increases the content of α-tocopherol (αT), the main vitamin E congener, in microalgae, but little is known regarding its effect on other tocochromanols, such as tocomonoenols and tocotrienols. We therefore quantified the concentrations of T, T1, and T3, in freeze-dried biomass from nitrogen-sufficient, and nitrogen-depleted Monodopsis subterranea (Eustigmatophyceae). The identities of isomers of αT1 were confirmed by LC-MS and GC-MS. αT was the predominant tocochromanol (82% of total tocochromanols). αT1 was present in higher quantities than the sum of all T3 (6% vs. 1% of total tocochromanols). 11'-αT1 was the main αT1 isomer. Nitrogen depletion increased αT, but not αT1 or T3 in M. subterranea. In conclusion, nitrogen depletion increased the content of αT, the biologically most active form of vitamin E, in M. subterranea without affecting αT1 and T3 and could potentially be used as a strategy to enhance its nutritional value but not to increase αT1 content, indicating that αT1 accumulation is independent of that of αT in microalgae.
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Affiliation(s)
| | - Alejandra Muñoz‐González
- Institute of Nutritional Sciences (140b)University of HohenheimStuttgartGermany
- School of Food TechnologyUniversity of Costa RicaSan PedroCosta Rica
| | - Katja Lehnert
- Institute of Food Chemistry (170b)University of HohenheimStuttgartGermany
| | - Konstantin Frick
- Institute of Interfacial Process Engineering and Plasma TechnologyUniversity of StuttgartStuttgartGermany
| | - Ulrike Schmid‐Staiger
- Innovation Field Functional IngredientsFraunhofer Institute for Interfacial Engineering and Biotechnology IGBStuttgartGermany
| | - Walter Vetter
- Institute of Food Chemistry (170b)University of HohenheimStuttgartGermany
| | - Jan Frank
- Institute of Nutritional Sciences (140b)University of HohenheimStuttgartGermany
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3
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Hammerschick T, Vetter W. Profiling and Isolation of Ten Rare Branched-Chain Alkylresorcinols in Quinoa. Molecules 2023; 28:5220. [PMID: 37446882 DOI: 10.3390/molecules28135220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Alkylresorcinols (∑ARs) are bioactive lipid compounds predominantly found in cereals. These amphiphilic compounds exist in a high structural diversity and can be divided into two main groups, i.e., 5-alkylresorcinols (ARs) and 2-methyl-5-alkylresorcinols (mARs). The pseudocereal quinoa has a very unique AR profile, consisting not only of straight-chain alkyl chains but also iso- and anteiso-branched isomers. Here, we describe a method for the isolation of such methyl-branched ARs and mARs from quinoa. The enrichment of the ∑AR fraction from the lipid extracts by centrifugal partition chromatography (CPC) was followed by ∑AR profiling using countercurrent chromatography (CCC) and GC/MS analysis of CCC fractions. A total of 112 ∑ARs could be detected, 63 of which had not been previously described in quinoa. Due to this high number of ∑ARs, the direct isolation of individual ARs was not possible using conventional CCC. Instead, the more powerful heart-cut mode was applied to enrich the target compounds. A final purification step-the separation of CCC-co-eluting mARs from ARs -was performed via silver ion chromatography. Altogether, ten rare branched-chain ∑ARs (five iso-branched mARs and five anteiso-branched ARs, including mAR19:0-i and AR20:0-a) were isolated with purities up to 98% in the double-digit mg range.
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Affiliation(s)
- Tim Hammerschick
- Institute of Food Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany
| | - Walter Vetter
- Institute of Food Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany
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4
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Rüttler F, Ormos R, Cannas J, Hammerschick T, Schlag S, Vetter W. Sample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode. Anal Bioanal Chem 2023:10.1007/s00216-023-04766-9. [PMID: 37285025 DOI: 10.1007/s00216-023-04766-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/27/2023] [Accepted: 05/18/2023] [Indexed: 06/08/2023]
Abstract
Countercurrent chromatography (CCC) is a preparative instrumental method where both the mobile and stationary phases are liquids and which are predominantly used for the isolation of natural products. In this study, we widened the scope of CCC by using it as an instrumental method for the direct enrichment of the free sterol fraction from plant oils to which they contribute with ~ 1%. For the enrichment of sterols in a narrow band, we employed the so-called co-current CCC (ccCCC) mode in which both liquid phases of the solvent system (here: n-hexane/ethanol/methanol/water (34:11:12:2, v/v/v/v)) are moved at different flow rates in the same direction. Different from previous applications of ccCCC, the lower and predominant "stationary" phase (LPs) was pumped twice as fast as the mobile upper phase (UPm). This novel reversed ccCCC mode improved the performance but also required a higher demand of LPs compared to UPm. Therefore, the exact phase composition of UPm and LPs was determined by gas chromatography and Karl Fischer titration. This step enabled the direct preparation of LPs which considerably reduced the waste of solvents. Internal standards (phenyl-substituted fatty acid alkyl esters) were synthesised and utilised to frame the free sterol fraction. This approach allowed a fractionation of free sterols based on the UV signal and compensated run-to-run variations. The reversed ccCCC method was then applied to the sample preparation of five vegetable oils. In addition to free sterols, free tocochromanols (tocopherols, vitamin E) were also eluted in the same fraction as free sterols.
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Affiliation(s)
- Felix Rüttler
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany
| | - Rosalie Ormos
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany
| | - Jil Cannas
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany
| | - Tim Hammerschick
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany
| | - Sarah Schlag
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany
| | - Walter Vetter
- Department of Food Chemistry (170B), Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, D-70599, Stuttgart, Germany.
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5
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Hammerschick T, Wagner T, Deser C, Vetter W. Isolation of plastochromanol-8 from flaxseed oil by countercurrent separation methods. Food Chem 2023; 409:135345. [PMID: 36592601 DOI: 10.1016/j.foodchem.2022.135345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/21/2022] [Accepted: 12/27/2022] [Indexed: 12/29/2022]
Abstract
The naturally occurring antioxidant plastochromanol-8 (PC-8) is a member of the tocochromanol (vitamin E) family which features eight unsaturated isoprene units in the side chain compared to three in the case of γ-tocotrienol. Due to the lack of a commercially available PC-8 standard, we developed a route to gain relevant amounts of highly pure PC-8. Specifically, ∼320 g flaxseed oil was saponified and the bulky PC-8 was enriched by gel permeation chromatography. It followed countercurrent chromatography using the solvent system n-hexane/benzotrifluoride/acetonitrile (20:7:13, v/v/v). The final purification was achieved by centrifugal partition chromatography using the novel solvent system hexamethyldisiloxane/acetonitrile (1:1, v/v). This step provided ∼26 mg PC-8 (>99.5 %, according to HPLC, GC and NMR analysis). Two further, hitherto unknown minor tocochromanols (<1 % of PC-8) were detected and could be identified to be plastochromanol-7 (PC-7) and plastochromanol-9 (PC-9), i.e. tocochromanols with seven and nine unsaturated isoprene units, respectively, in the side chain.
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Affiliation(s)
- Tim Hammerschick
- University of Hohenheim, Institute of Food Chemistry, Department of Food Chemistry (170b), D-70593 Stuttgart, Germany
| | - Tim Wagner
- University of Hohenheim, Institute of Food Chemistry, Department of Food Chemistry (170b), D-70593 Stuttgart, Germany
| | - Christina Deser
- University of Hohenheim, Institute of Food Chemistry, Department of Food Chemistry (170b), D-70593 Stuttgart, Germany
| | - Walter Vetter
- University of Hohenheim, Institute of Food Chemistry, Department of Food Chemistry (170b), D-70593 Stuttgart, Germany.
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6
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Online hyphenation of centrifugal partition chromatography with countercurrent chromatography (CPC-CCC) and its application to the separation of saturated alkylresorcinols. Anal Bioanal Chem 2022; 414:5043-5051. [PMID: 35639138 PMCID: PMC9234026 DOI: 10.1007/s00216-022-04136-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 11/08/2022]
Abstract
Centrifugal partition chromatography (CPC) and countercurrent chromatography (CCC) are two preparative techniques mainly used for the isolation and purification of natural products. While CPC benefits from a larger sample capacity, CCC typically provides better peak resolutions and hereby higher purities. In this study, we aimed to combine both advantages by the direct linking of CPC and CCC which was achieved by installation of switching valves and connection tube. The hyphenated CPC-CCC setup was tested with major alkylresorcinols which were obtained from a transesterified and hydrogenated rye extract. Injections of 1- and 5-g samples into the individual CCC system confirmed the limited sample capacity because of immediate flooding with the 5-g sample (total loss of stationary phase). In comparison, the CPC system was stable with 5- and 10-g samples but the peak resolution with 1-g sample was poorer than with the CCC system. Injections of 5- and 10-g samples into the CPC-CCC system were successful. However, a sample load of 10 g resulted in lower purities of the alkylresorcinols (80% or less) due to peak tailing. By contrast, injection of 5-g sample provided high amounts of ~ 1.2 g alkylresorcinols with purities of > 95%.
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7
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Montoya-Arroyo A, Lehnert K, Lux PE, Jiménez VM, Esquivel P, Silva-Benavides AM, Vetter W, Frank J. 11'-α-Tocomonoenol is the major α-tocomonoenol isomer in cyanobacteria and microalgae from Costa Rica. J Food Compost Anal 2022. [DOI: 10.1016/j.jfca.2021.104325] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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8
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Quantification of tocochromanols in vitamin E dietary supplements by instrumental thin-layer chromatography. Eur Food Res Technol 2022. [DOI: 10.1007/s00217-022-03993-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractA variety of vitamin E dietary supplement capsules (DSC) based on different natural oils or synthesis products are currently found on the market whose vitamin contents need to be controlled before and after marketing. Here, we present an instrumental thin-layer chromatography (TLC) method which allows a direct determination of all tocopherols (T) and tocotrienols (T3) as well as α-tocopherol acetate simultaneously in one run with short analysis time. For this purpose, contents of the DSC were extracted, applied on silica gel 60 plates, and developed with n-hexane/ethyl acetate/acetic acid, 90:10:2 (v/v/v) as mobile phase. The UV scan of the plate at 293 nm was used for quantification based on the peak height. Following the scan, the plate was treated with 10% sulphuric acid in methanol which led to characteristic yellow-to-brown colouring of the tocochromanol spots which allowed to distinguish tocochromanols from matrix components with similar Rf values. In most cases, determined vitamin E contents matched well with the information listed on the label of the investigated DSC samples. The method is fast, easy to perform and gently treats the analytes as it requires no thermal treatment prior to quantification, which makes it suitable as a screening method.
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Tocochromanol Profiles in Chlorella sorokiniana, Nannochloropsis limnetica and Tetraselmis suecica Confirm the Presence of 11′-α-Tocomonoenol in Cultured Microalgae Independently of Species and Origin. Foods 2022; 11:foods11030396. [PMID: 35159546 PMCID: PMC8834470 DOI: 10.3390/foods11030396] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/20/2022] [Accepted: 01/24/2022] [Indexed: 02/01/2023] Open
Abstract
11′-α-Tocomonoenol (11′-αT1) is structurally related to vitamin E and has been quantified in the microalgae Tetraselmis sp. and Nannochloropsis oceanica. However, it is not known whether 11′-αT1 is present in other microalgae independent of species and origin. The aim of this study was to analyze the tocochromanol profiles of Chlorella sorokiniana, Nannochloropsis limnetica, and Tetraselmis suecica and to determine if 11′-αT1 is present in these microalgae. Cultured microalgae were freeze-dried and the presence and identity of α-tocomonoenols were confirmed by LC-MSn (liquid chromatography coupled to mass spectroscopy) and GC-MS (gas chromatography coupled to mass spectroscopy). Tocochromanol profiles were determined by HPLC-FLD (liquid chromatography with fluorescence detection) and fatty acid profiles (as fatty acid methyl esters; FAME) by GC-MS. As confirmed by LC-MSn and GC-MS, 11′-αT1 was the dominant αT1 isomer in cultured microalgae instead of 12′-αT1, the isomer also known as marine-derived tocopherol. αT1 represented less than 1% of total tocochromanols in all analyzed samples and tended to be more abundant in microalgae with higher proportions of polyunsaturated fatty acids. In conclusion, our findings confirm that αT1 is not restricted to terrestrial photosynthetic organisms, but can also accumulate in microalgae of different species, with 11′-αT1—and not the marine-derived tocopherol (12′-αT1)—as the predominant αT1 isomer.
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Kröpfl A, Nemetz NJ, Goncalves Peca A, Vetter W. Countercurrent chromatography isolation of 11′‐γ‐tocomonoenol from pumpkin seed oil with detection of novel minor tocochromanols. J AM OIL CHEM SOC 2022. [DOI: 10.1002/aocs.12559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alexander Kröpfl
- Department of Food Chemistry (170b) Institute of Food Chemistry, University of Hohenheim Stuttgart Germany
| | - Nicole Jasmin Nemetz
- Department of Food Chemistry (170b) Institute of Food Chemistry, University of Hohenheim Stuttgart Germany
| | - Andrea Goncalves Peca
- Department of Food Chemistry (170b) Institute of Food Chemistry, University of Hohenheim Stuttgart Germany
| | - Walter Vetter
- Department of Food Chemistry (170b) Institute of Food Chemistry, University of Hohenheim Stuttgart Germany
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11
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Montoya-Arroyo A, Wagner T, Sus N, Müller M, Kröpfl A, Vetter W, Frank J. Cytotoxicity, cellular uptake, and metabolism to short-chain metabolites of 11'-α-tocomonoenol is similar to RRR-α-tocopherol in HepG2 cells. Free Radic Biol Med 2021; 177:24-30. [PMID: 34666150 DOI: 10.1016/j.freeradbiomed.2021.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/02/2021] [Accepted: 10/08/2021] [Indexed: 02/03/2023]
Abstract
Contrary to the major vitamin E congener α-tocopherol, which carries a saturated sidechain, and α-tocotrienol, with a threefold unsaturated sidechain, little is known about the intracellular fate of α-tocomonoenol, a minor vitamin E derivative with a single double bond in C11'-position of the sidechain. We hypothesized that, due to structural similarities, the uptake and metabolism of α-tocomonoenol will resemble that of α-tocopherol. Cytotoxicity, cellular uptake of α-tocomonoenol, α-tocopherol and α-tocotrienol and conversion into the short-chain metabolites αCEHC and αCMBHC were studied in HepG2 cells. α-Tocomonoenol did not show significant effects on cell viability and its uptake was similar to that observed for α-tocopherol and significantly lower than for α-tocotrienol. α-Tocomonoenol was mainly metabolized to αCMBHC in liver cells, but to a lower extent than α-tocotrienol, while α-tocopherol was not metabolized in quantifiable amounts at all. In summary, the similarities in the cytotoxicity, uptake and metabolism of α-tocomonoenol and α-tocopherol suggest that this minor vitamin E congener deserves more attention in future research with regard to its potential vitamin E activity.
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Affiliation(s)
- Alexander Montoya-Arroyo
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, 70599, Stuttgart, Germany
| | - Tanja Wagner
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, 70599, Stuttgart, Germany
| | - Nadine Sus
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, 70599, Stuttgart, Germany
| | - Marco Müller
- Department of Food Chemistry (170b), Institute of Food Chemistry, University of Hohenheim, 70599, Stuttgart, Germany
| | - Alexander Kröpfl
- Department of Food Chemistry (170b), Institute of Food Chemistry, University of Hohenheim, 70599, Stuttgart, Germany
| | - Walter Vetter
- Department of Food Chemistry (170b), Institute of Food Chemistry, University of Hohenheim, 70599, Stuttgart, Germany
| | - Jan Frank
- Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, 70599, Stuttgart, Germany. http://www.nutrition.red
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Irías-Mata A, Sus N, Hug ML, Müller M, Vetter W, Frank J. α-Tocomonoenol Is Bioavailable in Mice and May Partly Be Regulated by the Function of the Hepatic α‑Tocopherol Transfer Protein. Molecules 2020; 25:molecules25204803. [PMID: 33086686 PMCID: PMC7588010 DOI: 10.3390/molecules25204803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/30/2020] [Accepted: 10/15/2020] [Indexed: 11/16/2022] Open
Abstract
Tocomonoenols are vitamin E derivatives present in foods with a single double bond at carbon 11' in the sidechain. The α-tocopherol transfer protein (TTP) is required for the maintenance of normal α-tocopherol (αT) concentrations. Its role in the tissue distribution of α-11'-tocomonoenol (αT1) is unknown. We investigated the tissue distribution of αT1 and αT in wild-type (TTP+/+) and TTP knockout (TTP-/-) mice fed diets with either αT or αT1 for two weeks. αT1 was only found in blood, not tissues. αT concentrations in TTP+/+ mice were in the order of adipose tissue > brain > heart > spleen > lungs > kidneys > small intestine > liver. Loss of TTP function depleted αT in all tissues. αT1, contrary to αT, was still present in the blood of TTP-/- mice (16% of αT1 in TTP+/+). Autoclaving and storage at room temperature reduced αT and αT1 in experimental diets. In conclusion, αT1 is bioavailable, reaches the blood in mice, and may not entirely depend on TTP function for secretion into the systemic circulation. However, due to instability of the test compounds in the experimental diets, further in vivo experiments are required to clarify the role of TTP in αT1 secretion. Future research should consider compound stability during autoclaving of rodent feed.
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Affiliation(s)
- Andrea Irías-Mata
- Department of Food Biofunctionality, Institute of Nutritional Sciences, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany; (A.I.-M.); (N.S.); (M.-L.H.)
| | - Nadine Sus
- Department of Food Biofunctionality, Institute of Nutritional Sciences, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany; (A.I.-M.); (N.S.); (M.-L.H.)
| | - Maria-Lena Hug
- Department of Food Biofunctionality, Institute of Nutritional Sciences, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany; (A.I.-M.); (N.S.); (M.-L.H.)
| | - Marco Müller
- Institute of Food Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany; (M.M.); (W.V.)
| | - Walter Vetter
- Institute of Food Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany; (M.M.); (W.V.)
| | - Jan Frank
- Department of Food Biofunctionality, Institute of Nutritional Sciences, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany; (A.I.-M.); (N.S.); (M.-L.H.)
- Correspondence: ; Tel.: +49-711-459-24459; Fax: +49-711-459-23386
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Wiedmaier‐Czerny N, Müller M, Vetter W. Heart‐Cut Two‐Dimensional Countercurrent Chromatography for the Isolation of a Furan Fatty Acid Triacylglycerol from Latex Gloves and Identification of Further Lipid Compounds. J AM OIL CHEM SOC 2020. [DOI: 10.1002/aocs.12333] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nina Wiedmaier‐Czerny
- Department of Food Chemistry (170b), Institute of Food ChemistryUniversity of Hohenheim Stuttgart D‐70593 Germany
| | - Marco Müller
- Department of Food Chemistry (170b), Institute of Food ChemistryUniversity of Hohenheim Stuttgart D‐70593 Germany
| | - Walter Vetter
- Department of Food Chemistry (170b), Institute of Food ChemistryUniversity of Hohenheim Stuttgart D‐70593 Germany
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14
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Müller M, Kröpfl A, Vetter W. Identification of two α-tocodienol isomers in palm oil after countercurrent chromatographic enrichment. Anal Bioanal Chem 2019; 412:795-802. [PMID: 31858167 DOI: 10.1007/s00216-019-02303-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/25/2019] [Accepted: 11/26/2019] [Indexed: 10/25/2022]
Abstract
Countercurrent chromatography (CCC) was used for the enrichment of α-tocodienol (α-T2), a rare vitamin E-related minor compound previously tentatively detected in palm oil. Hitherto, only one isomer has been mentioned to occur at traces in palm oil. However, CCC fractionation followed by GC/MS measurements of all fractions resulted in the detection of two α-T2 isomers in five different palm oil vitamin E dietary supplement capsules. Five repetitive CCC separations of ~ 1 g sample and additional purification steps by column chromatography provided ~ 2 mg of two equally abundant α-T2 isomers with a purity of ~ 85%. The positions of the double bonds in the alkyl side chain could be assigned by means of two characteristic chemical shifts in the 1H NMR spectrum. Accordingly, the structures of the α-T2 isomers were 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridec-3,11-dienyl)chroman-6-ol (double bonds in 3',11'-position) and 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridec-7,11-dienyl)chroman-6-ol (double bonds in 7',11'-position). Natural occurrence of both isomers was proven by GC/MS screening of crude palm oil after saponification and CCC separation. Moreover, GC/MS analysis allowed the tentative assignment of γ-tocomonoenol (γ-T1) and β-tocomonoenol (β-T1) as trace compounds in palm oil.
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Affiliation(s)
- Marco Müller
- Institute of Food Chemistry, Department of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, 70593, Stuttgart, Germany
| | - Alexander Kröpfl
- Institute of Food Chemistry, Department of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, 70593, Stuttgart, Germany
| | - Walter Vetter
- Institute of Food Chemistry, Department of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, 70593, Stuttgart, Germany.
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Gottstein V, Müller M, Günther J, Kuballa T, Vetter W. Direct 1H NMR Quantitation of Valuable Furan Fatty Acids in Fish Oils and Fish Oil Fractions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11788-11795. [PMID: 31565927 DOI: 10.1021/acs.jafc.9b04711] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Furan fatty acids (FuFAs) are a class of naturally occurring minor fatty acids with fish as the richest food source. Typically, FuFA analysis is cumbersome and involves several steps. We developed a quantitative 1H NMR method (qNMR) in which fish oil samples were directly measured after dilution with CDCl3 stabilized with silver (which was essential to prevent formation of radicals) and addition of an internal standard. The singlet at δ = 1.89 ppm was suitable for quantitation of monomethyl FuFAs, whereas the signal at δ = 1.83 ppm was suitable to quantitate dimethyl FuFAs. Using standard NMR tubes with 650 μL solvent, the limit of quantitation was 0.5 μg (dimethyl FuFAs) and 1.0 μg (monomethyl FuFAs). Applied to three fish oil and two enriched fish oil samples (sample weight, 10 mg), the final qNMR method resulted in similar total FuFA contents as determined in parallel by gas chromatography coupled to mass spectrometry.
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Affiliation(s)
- Vera Gottstein
- Institute of Food Chemistry, Department of Food Chemistry (170b) , University of Hohenheim , D-70593 Stuttgart , Germany
- CVUA Karlsruhe , Weißenburgerstraße 3 , 76187 Karlsruhe , Germany
| | - Marco Müller
- Institute of Food Chemistry, Department of Food Chemistry (170b) , University of Hohenheim , D-70593 Stuttgart , Germany
| | - Johannes Günther
- Spectroscopy Unit , Core Facility Hohenheim , D-70593 Stuttgart , Germany
| | - Thomas Kuballa
- CVUA Karlsruhe , Weißenburgerstraße 3 , 76187 Karlsruhe , Germany
| | - Walter Vetter
- Institute of Food Chemistry, Department of Food Chemistry (170b) , University of Hohenheim , D-70593 Stuttgart , Germany
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Vetter W, Müller M, Sommer K, Schröder M, Hammann S. Development of equivalent chain length (ECL) rules for lipid compounds. J Chromatogr A 2019; 1599:187-195. [DOI: 10.1016/j.chroma.2019.04.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 10/27/2022]
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17
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Sprengel J, Wieselmann S, Kröpfl A, Vetter W. High amounts of chlorinated paraffins in oil-based vitamin E dietary supplements on the German market. ENVIRONMENT INTERNATIONAL 2019; 128:438-445. [PMID: 31082722 DOI: 10.1016/j.envint.2019.04.065] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 05/26/2023]
Abstract
Chlorinated paraffins (CPs) are a group of man-made pollutants of growing environmental concern. Short-chain chlorinated paraffins (SCCPs) were recently classified as persistent organic pollutants (POPs), while medium-chain chlorinated paraffins (MCCPs) are still unregulated. Foodstuff is a major pathway for the human CP intake, and the regular diet has been analyzed in several studies recently. However, dietary supplements (DS) had not been analyzed on CPs. Our goal was to investigate the occurrence of CPs in DS and to evaluate the possible threat for the consumers. DS (n = 25) made from plant or fish oils were selected on the German market with main emphasis on vitamin E products. The lipid components were removed by sulphuric acid treatment and silica gel column chromatography. CP quantification was performed via gas chromatography coupled to electron capture negative ion mass spectrometry. Six vitamin E preparations containing palm oil showed alarmingly high CP concentrations of >35 μg/g fat. Six other DS contained much lower CP amounts (<4 μg/g fat). If consumed as recommended, the mean daily intake of CPs (5.5 μg SCCPs + 38 μg MCCPs) via palm oil based DS surpassed that of the regular diet by a factor of 4 for SCCPs and 13 for MCCPs, exceeding the PCB intake via food by up to two orders of magnitude. Samples reached up to 26% of the TDI of MCCPs for an average European adult. Consequently, the P95 intake of those samples would amount to ~43 mg CPs per year. The CP contamination probably originated from raw material, as CPs were also found in palm oils and vitamin E concentrates made from palm oil. Our findings suggest that DS can contain high amounts of contaminants that compromise the purpose of the product and should be considered for regular CP monitoring.
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Affiliation(s)
- Jannik Sprengel
- University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany
| | - Sina Wieselmann
- University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany
| | - Alexander Kröpfl
- University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany
| | - Walter Vetter
- University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany.
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18
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Lipid profiling and analytical discrimination of seven cereals using high temperature gas chromatography coupled to high resolution quadrupole time-of-flight mass spectrometry. Food Chem 2019; 282:27-35. [DOI: 10.1016/j.foodchem.2018.12.109] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 01/21/2023]
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