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Kranzler M, Walser V, Stark TD, Ehling-Schulz M. A poisonous cocktail: interplay of cereulide toxin and its structural isomers in emetic Bacillus cereus. Front Cell Infect Microbiol 2024; 14:1337952. [PMID: 38596651 PMCID: PMC11002159 DOI: 10.3389/fcimb.2024.1337952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/11/2024] [Indexed: 04/11/2024] Open
Abstract
Food intoxications evoked by emetic Bacillus cereus strains constitute a serious threat to public health, leading to emesis and severe organ failure. The emetic peptide toxin cereulide, assembled by the non-ribosomal peptide synthetase CesNRPS, cannot be eradicated from contaminated food by usual hygienic measures due to its molecular size and structural stability. Next to cereulide, diverse chemical variants have been described recently that are produced concurrently with cereulide by CesNRPS. However, the contribution of these isocereulides to the actual toxicity of emetic B. cereus, which produces a cocktail of these toxins in a certain ratio, is still elusive. Since cereulide isoforms have already been detected in food remnants from foodborne outbreaks, we aimed to gain insights into the composition of isocereulides and their impact on the overall toxicity of emetic B. cereus. The amounts and ratios of cereulide and isocereulides were determined in B. cereus grown under standard laboratory conditions and in a contaminated sample of fried rice balls responsible for one of the most severe food outbreaks caused by emetic B. cereus in recent years. The ratios of variants were determined as robust, produced either under laboratory or natural, food-poisoning conditions. Examination of their actual toxicity in human epithelial HEp2-cells revealed that isocereulides A-N, although accounting for only 10% of the total cereulide toxins, were responsible for about 40% of the total cytotoxicity. An this despite the fact that some of the isocereulides were less cytotoxic than cereulide when tested individually for cytotoxicity. To estimate the additive, synergistic or antagonistic effects of the single variants, each cereulide variant was mixed with cereulide in a 1:9 and 1:1 binary blend, respectively, and tested on human cells. The results showed additive and synergistic impacts of single variants, highlighting the importance of including not only cereulide but also the isocereulides in routine food and clinical diagnostics to achieve a realistic toxicity evaluation of emetic B. cereus in contaminated food as well as in patient samples linked to foodborne outbreaks. Since the individual isoforms confer different cell toxicity both alone and in association with cereulide, further investigations are needed to fully understand their cocktail effect.
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Affiliation(s)
- Markus Kranzler
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Veronika Walser
- Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Freising, Germany
| | - Timo D. Stark
- Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Freising, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
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2
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Hofstetter CK, Dunkel A, Bussy U, Wimmer M, Kauz T, Stark TD, Didzbalis J, Dawid C, Hofmann T. Toward Unified Flavor Quantitation in Cocoa-Based Products. J Agric Food Chem 2023; 71:20243-20250. [PMID: 38084639 DOI: 10.1021/acs.jafc.3c06868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Because food flavor is perceived through a combination of odor and taste, an analytical method that covers both dimensions would be very beneficial for mapping the consistent product quality over the entirety of a manufacturing process. Such a method, so-called "unified flavor quantitation", has been successfully applied to several different food products in recent years. The simultaneous detection of aroma and taste compounds by means of ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) enables the analysis and quantification of an enormously large number of compounds in a single run. To evaluate the limits of this method, chocolate, a high-fat, complex matrix, was selected. In 38 distinct commercial chocolate samples, 20 flavor-active acids, aldehydes, and sugars were analyzed after a simple, rapid extraction step followed by derivatization with 3-nitrophenylhydrazine using a single UHPLC-MS/MS method. The results obtained highlight the great potential of the "unified flavor quantitation" approach and demonstrate the possibility of high-throughput quantitation of key aroma- and taste-active molecules in a single assay.
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Affiliation(s)
- Christoph Konrad Hofstetter
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Andreas Dunkel
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Ugo Bussy
- Mars Inc., 6885 Elm Street, McLean, Virginia 22101, United States
| | - Miriam Wimmer
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Thomas Kauz
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - John Didzbalis
- Mars Inc., 6885 Elm Street, McLean, Virginia 22101, United States
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany
- Professorship for Functional Phytometabolomics, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
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3
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Albien AL, Stark TD. (Bio)active Compounds in Daisy Flower ( Bellis perennis). Molecules 2023; 28:7716. [PMID: 38067445 PMCID: PMC10707873 DOI: 10.3390/molecules28237716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
The common daisy (Bellis perennis) belongs to the family Asteraceae and, in recent years, some new research has been published on the bioactive compounds and biological activities of its extracts. In 2014, the knowledge was partially summarized, but several new studies have been published in the last nine years. In addition, the substances were tabularly consolidated to give a comprehensive overview of over 310 individual components, compound classes, and bioactivities, as well as their accurate plant organ origin. The latest results have shown that the plant has antioxidative, antimicrobial, anticancerogenic, wound healing, antidepressive, anxiolytic, nephroprotective, and insulin mimetic effects, as well as an effect on lipid metabolism. Some studies in the field of homeopathy were also listed. Ideally, a biological effect and one or several compound(s) can be correlated. However, the compounds of the extracts used have often been qualified and quantified, but it remains unclear which of these substances have an activity. The works often stick at the level of the crude extract or a fraction, but not at a single purified and tested compound and, consequently, they are hampered by a missing comprehensive bioactivity workflow. This review provides a critical overview and gaps and offers a basis for further research in this area.
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Affiliation(s)
- Anna-Lena Albien
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
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4
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Jenull S, Bauer T, Silbermayr K, Dreer M, Stark TD, Ehling-Schulz M. The toxicological spectrum of the Bacillus cereus toxin cereulide points towards niche-specific specialisation. Environ Microbiol 2023; 25:2231-2249. [PMID: 37354053 DOI: 10.1111/1462-2920.16454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/06/2023] [Indexed: 06/26/2023]
Abstract
Most microbes share their environmental niches with very different forms of life thereby engaging in specialised relationships to enable their persistence. The bacterium Bacillus cereus occurs ubiquitously in the environment with certain strain backgrounds causing foodborne and opportunistic infections in humans. The emetic lineage of B. cereus is capable of producing the toxin cereulide, which evokes emetic illnesses. Although food products favouring the accumulation of cereulide are known, the ecological role of cereulide and the environmental niche of emetic B. cereus remain elusive. To better understand the ecology of cereulide-producing B. cereus, we systematically assayed the toxicological spectrum of cereulide on a variety of organisms belonging to different kingdoms. As cereulide is a potassium ionophore, we further tested the effect of environmental potassium levels on the action of cereulide. We found that adverse effects of cereulide exposure are species-specific, which can be exacerbated with increased environmental potassium. Additionally, we demonstrate that cereulide is produced within an insect cadaver indicating its potential ecological function for a saprophytic lifestyle. Collectively, distinct cereulide susceptibilities of other organisms may reflect its role in enabling competitive niche specialization of emetic B. cereus.
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Affiliation(s)
- Sabrina Jenull
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tobias Bauer
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Katja Silbermayr
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Maximilian Dreer
- Department of Functional and Evolutionary Ecology, Archaea Biology and Ecogenomics Unit, University of Vienna, Vienna, Austria
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
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Ranner JL, Schalk S, Martyniak C, Parniske M, Gutjahr C, Stark TD, Dawid C. Primary and Secondary Metabolites in Lotus japonicus. J Agric Food Chem 2023. [PMID: 37466334 DOI: 10.1021/acs.jafc.3c02709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Lotus japonicus is a leguminous model plant used to gain insight into plant physiology, stress response, and especially symbiotic plant-microbe interactions, such as root nodule symbiosis or arbuscular mycorrhiza. Responses to changing environmental conditions, stress, microbes, or insect pests are generally accompanied by changes in primary and secondary metabolism to account for physiological needs or to produce defensive or signaling compounds. Here we provide an overview of the primary and secondary metabolites identified in L. japonicus to date. Identification of the metabolites is mainly based on mass spectral tags (MSTs) obtained by gas chromatography linked with tandem mass spectrometry (GC-MS/MS) or liquid chromatography-MS/MS (LC-MS/MS). These MSTs contain retention index and mass spectral information, which are compared to databases with MSTs of authentic standards. More than 600 metabolites are grouped into compound classes such as polyphenols, carbohydrates, organic acids and phosphates, lipids, amino acids, nitrogenous compounds, phytohormones, and additional defense compounds. Their physiological effects are briefly discussed, and the detection methods are explained. This review of the exisiting literature on L. japonicus metabolites provides a valuable basis for future metabolomics studies.
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Affiliation(s)
- Josef L Ranner
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Sabrina Schalk
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Cindy Martyniak
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Martin Parniske
- Faculty of Biology, Genetics, University of Munich (LMU), Großhaderner Straße 2-4, 82152 Martinsried, Germany
| | - Caroline Gutjahr
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Professorship of Functional Phytometabolomics, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
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6
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Bösl M, Dunkel A, Hartl D, Dollinger A, Spaccasassi A, Stark TD, Dawid C, Hofmann TF. Toward High-Throughput Analysis of Aroma Compounds Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry: Screening of Key Food Odorants in Various Foods. J Agric Food Chem 2023. [PMID: 37228041 DOI: 10.1021/acs.jafc.3c00935] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Recent studies show the immense capacities of the unified quantitation of aroma and taste compounds using liquid chromatography-mass spectrometry (LC-MS). The goal of this study was to highlight the broad application of this unified method. Thus, a stable isotope dilution analysis quantification method of the most important key food odorants in various food categories by LC-MS was developed. Using the well-known derivatization agent 3-nitrophenylhydrazine for carbonyl derivatization and a newly developed approach for alcohol and thiol derivatization, a method for the quantitation of 20 key food odorants was established. Intraday precision was determined to be ≤26%, and interday precision was between 24 and 31%. Limits of quantitation were determined between 0.014 and 283 μg/kg. The work shows that a wide array of aroma compounds can be analyzed accurately by LC-MS.
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Affiliation(s)
- Markus Bösl
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Andreas Dunkel
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Daniela Hartl
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Anja Dollinger
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Andrea Spaccasassi
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
| | - Thomas F Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, Freising 85354, Germany
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7
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Mekuete LBK, Tsopgni WDT, Nkojap AK, Kojom JJW, Stark TD, Fouokeng Y, Dongmo AB, Azeufack LT, Azebaze AGB. Rotenoids and Isoflavones from Xeroderris stuhlmannii (Taub.) Mendonça & E.P. Souza and Their Biological Activities. Molecules 2023; 28:molecules28062846. [PMID: 36985817 PMCID: PMC10059994 DOI: 10.3390/molecules28062846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/11/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
The phytochemical study of the ethanolic extract of the leaf of Xeroderris stuhlmannii led to the isolation of five hitherto unreported compounds including two isoflavones (1-2), and three rotenoids (3-5), along with eight known isoflavonoid derivatives (6-13) and one pterocarpan derivative (14). The structures of the new compounds and those of the known ones were established by the spectroscopic (1D and 2D NMR) and spectrometric (HRESIMS) techniques as well as a comparison of their spectroscopic data with those reported in the literature. The leaf extract, fractions, and isolated compounds were tested for their antibacterial effects against nine bacterial strains. Compounds 3, 8, 11, and 12 showed a significant antibacterial effect, with a minimum inhibitory concentration (MIC) value of 62.5 µg/mL each, against Salmonella typhi, Staphylococcus aureus, Klessiella pneumonae, and Escherichia coli, respectively. In addition, the leaf extract, fractions, and isolated compounds were tested for their antifungal effects against four fungal strains. The hexane fraction showed a significant antifungal effect with an MIC value of 125 µg/mL against Candida parasilosis, whereas compounds 3, 8, and 12 showed significant antifungal activity with an MIC value of 62.5 µg/mL, each against Candida parasilosis, Candida albicans, and Candida krusei, respectively.
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Affiliation(s)
- Livie Blondèle Kenou Mekuete
- Research Unit of Environmental and Applied Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
- Department of Chemistry, Faculty of Sciences, University of Douala, Douala 24157, Cameroon
| | - Willifred Dongmo Tékapi Tsopgni
- Department of Chemistry, Faculty of Sciences, University of Douala, Douala 24157, Cameroon
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, 85354 Freising, Germany
| | - Augustine Kuinze Nkojap
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Douala, Douala 24517, Cameroon
| | - Jacquy Joyce Wanche Kojom
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Douala, Douala 24517, Cameroon
| | - Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, 85354 Freising, Germany
| | - Yannick Fouokeng
- Department of Chemistry, Faculty of Sciences, University of Douala, Douala 24157, Cameroon
| | - Alain Bertrand Dongmo
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Douala, Douala 24517, Cameroon
| | - Léon Tapondjou Azeufack
- Research Unit of Environmental and Applied Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
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Patterson S, Waters ME, Braman N, Willson R, Hill RA, Magolan J, Hofmann T, Stark TD, Balemba OB. Garcinia buchananii stem bark extract and its bioactive constituents manniflavanone, GB-2 and buchananiflavanone attenuate intestinal inhibitory neuromuscular transmission. J Smooth Muscle Res 2023; 59:34-57. [PMID: 37407438 DOI: 10.1540/jsmr.59.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023] Open
Abstract
Garcinia buchananii stem bark extract (GBB), commonly used for treating diarrhea in Africa, triggers ectopic aboral contractions, causing inhibition of propulsive motility in the colon ex vivo. To determine whether or not these effects were associated with decreased inhibitory neuromuscular transmission, the responsible constituent compounds, and mechanisms of action, we studied the effects of GBB and specific fractions and flavanones isolated from GBB on intestinal motility using pellet propulsion assays in guinea pig distal colons. In addition, microelectrode recordings were used to measure the effects on the inhibitory junction potentials (IJPs) in the porcine ileum and descending colon smooth muscle. Psychoactive Drug Screening Program secondary receptor functional assays were used to determine whether or not GBB and its constituent compounds act via purinergic (P2Y) and muscarinic receptors. GBB inhibited propulsive motility, but (2R,3S,2″R,3″R)-manniflavanone (MNF), (2R,3S,2″R,3″R)-GB-2 (GB-2) and (2R,3S,2″S)-buchananiflavanone (BNF), the main ingredients of GBB, did not affect motility. We discovered that, in the porcine descending colon, IJPs contained purinergic, nitrergic, and nonpurinergic nonnitrergic components. Furthermore, ileal IJPs were purely purinergic. GBB blocked all components of IJPs, while MNF and GB-2 inhibited purinergic IJPs only. BNF inhibited the purinergic and nonpurinergic components of IJPs. MRS2365, a Y1 (P2Y) agonist, did not evoke sustained membrane hyperpolarization in the presence of GBB. However, GBB, MNF, GB-2 and BNF did not affect P2Y or muscarinic receptors. In conclusion, inhibitory neuromuscular transmission in the porcine descending colon involves all components of IJPs. GBB decreases inhibitory neuromuscular transmission, likely by the actions of MNF, GB-2 and BNF. These effects do not involve P2Y or muscarinic receptors.
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Affiliation(s)
- Savannah Patterson
- Department of Biological Sciences/WWAMI, University of Idaho, 875 Perimeter Drive, LSS 252, Moscow, ID 83844, USA
| | - Michael Elder Waters
- Department of Biological Sciences/WWAMI, University of Idaho, 875 Perimeter Drive, LSS 252, Moscow, ID 83844, USA
| | - Nancy Braman
- Department of Biological Sciences/WWAMI, University of Idaho, 875 Perimeter Drive, LSS 252, Moscow, ID 83844, USA
| | - Roan Willson
- Department of Biological Sciences/WWAMI, University of Idaho, 875 Perimeter Drive, LSS 252, Moscow, ID 83844, USA
| | - Rodney A Hill
- School of Biomedical Sciences, Charles Sturt University, Australia
| | - Jakob Magolan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner Str. 34, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner Str. 34, 85354 Freising, Germany
| | - Onesmo B Balemba
- Department of Biological Sciences/WWAMI, University of Idaho, 875 Perimeter Drive, LSS 252, Moscow, ID 83844, USA
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Laupheimer S, Kurzweil L, Proels R, Unsicker SB, Stark TD, Dawid C, Hückelhoven R. Volatile-mediated signalling in barley induces metabolic reprogramming and resistance against the biotrophic fungus Blumeria hordei. Plant Biol (Stuttg) 2023; 25:72-84. [PMID: 36377298 DOI: 10.1111/plb.13487] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Plants have evolved diverse secondary metabolites to counteract biotic stress. Volatile organic compounds (VOCs) are released upon herbivore attack or pathogen infection. Recent studies suggest that VOCs can act as signalling molecules in plant defence and induce resistance in distant organs and neighbouring plants. However, knowledge is lacking on the function of VOCs in biotrophic fungal infection on cereal plants. We analysed VOCs emitted by 13 ± 1-day-old barley plants (Hordeum vulgare L.) after mechanical wounding using passive absorbers and TD-GC/MS. We investigated the effect of pure VOC and complex VOC mixtures released from wounded plants on the barley-powdery mildew interaction by pre-exposure in a dynamic headspace connected to a powdery mildew susceptibility assay. Untargeted metabolomics and lipidomics were applied to investigate metabolic changes in sender and receiver barley plants. Green leaf volatiles (GLVs) dominated the volatile profile of wounded barley plants, with (Z)-3-hexenyl acetate (Z3HAC) as the most abundant compound. Barley volatiles emitted after mechanical wounding enhanced resistance in receiver plants towards fungal infection. We found volatile-mediated modifications of the plant-pathogen interaction in a concentration-dependent manner. Pre-exposure with physiologically relevant concentrations of Z3HAC resulted in induced resistance, suggesting that this GLV is a key player in barley anti-pathogen defence. The complex VOC mixture released from wounded barley and Z3HAC induced e.g. accumulation of chlorophyll, linolenic acid and linolenate-conjugated lipids, as well as defence-related secondary metabolites, such as hordatines in receiving plants. Barley VOCs hence induce a complex physiological response and disease resistance in receiver plants.
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Affiliation(s)
- S Laupheimer
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - L Kurzweil
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - R Proels
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - S B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Jena, Germany
| | - T D Stark
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - C Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - R Hückelhoven
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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10
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Baur S, Bellé N, Hausladen H, Wurzer S, Brehm L, Stark TD, Hückelhoven R, Hofmann T, Dawid C. Correction to Quantitation of Toxic Steroidal Glycoalkaloids and Newly Identified Saponins in Post-Harvest Light-Stressed Potato ( Solanum tuberosum L.) Varieties. J Agric Food Chem 2022; 70:9817. [PMID: 35900379 DOI: 10.1021/acs.jafc.2c04727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
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11
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Baur S, Bellé N, Hausladen H, Wurzer S, Brehm L, Stark TD, Hücklhoven R, Hofmann T, Dawid C. Quantitation of Toxic Steroidal Glycoalkaloids and Newly Identified Saponins in Post-Harvest Light-Stressed Potato ( Solanum tuberosum L.) Varieties. J Agric Food Chem 2022; 70:8300-8308. [PMID: 35775364 DOI: 10.1021/acs.jafc.2c02578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although domesticated potatoes contain a large variety of steroidal glycoalkaloids (SGAs) and saponins, in the past, many research projects mainly focused on the two major SGAs, α-solanine and α-chaconine. This study investigates the quantitative changes, induced by post-harvest LED light exposure, of six SGAs and four saponins in 12 potato cultivars at three different time points (1, 7, and 16 days), by using ultra-performance liquid chromatography tandem mass spectrometry. Altogether, SGA contents of 3.0-17.1 mg/100 g fresh weight (FW) could be observed in the analyzed tubers with potato varieties highly exceeding the newly discussed safety limit of 10 mg/100 g. The overall contents of 0.1-5.4 mg/100 g FW of the so far barely studied saponins, like protoneodioscin or barogenin-solatrioside, highly differed between the assayed potato cultivars. Furthermore, cultivar-specific regulations of SGAs and saponins could be observed due to light exposure.
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Affiliation(s)
- Sebastian Baur
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Nicole Bellé
- Chair of Phytopathology, Technische Universität München, Emil-Ramann-Straße 2, 85354 Freising, Germany
| | - Hans Hausladen
- Plant Technology Center, Technische Universität München, Dürnast 9, 85354 Freising, Germany
| | - Sebastian Wurzer
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Laura Brehm
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Ralph Hücklhoven
- Chair of Phytopathology, Technische Universität München, Emil-Ramann-Straße 2, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354 Freising, Germany
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12
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Christa P, Dunkel A, Krauss A, Stark TD, Dawid C, Hofmann T. Discovery and Identification of Tastants and Taste-Modulating N-Acyl Amino Acid Derivatives in Traditional Korean Fermented Dish Kimchi Using a Sensomics Approach. J Agric Food Chem 2022; 70:7500-7514. [PMID: 35674110 DOI: 10.1021/acs.jafc.2c02623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Sensory-guided fractionation by means of ultrafiltration and gel permeation chromatography followed by high-performance liquid chromatography, synthesis, liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantitation, and taste re-engineering experiments revealed taste-active and taste-enhancing compounds contributing to the umami, mouthful and complex taste profile of the fermented Korean dish, kimchi. Besides basic taste-active compounds, in particular, various N-acylated amino acids deriving from succinic acid and lactic acid imparted taste-modulating properties in food matrices. Taste threshold concentrations were determined to evaluate intrinsic and modulating effects. Quantitation of N-acylated amino acids in kimchi following synthesis revealed the presence of numerous derivatives showing taste-active properties. Sensory evaluation including recombination and partial addition experiments highlighted that both the N-lactoyl- and the N-succinoyl amino acid derivatives contribute to increasing the fullness, volume, and complexity of food matrices, whereas the latter directly contributes to the overall taste of kimchi in natural concentrations.
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Affiliation(s)
- Peter Christa
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Andreas Dunkel
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Alin Krauss
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
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13
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Utz F, Spaccasassi A, Kreissl J, Stark TD, Tanger C, Kulozik U, Hofmann T, Dawid C. Sensomics-Assisted Aroma Decoding of Pea Protein Isolates (Pisum sativum L.). Foods 2022; 11:foods11030412. [PMID: 35159561 PMCID: PMC8834122 DOI: 10.3390/foods11030412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/20/2022] [Accepted: 01/27/2022] [Indexed: 02/01/2023] Open
Abstract
The aroma of pea protein (Pisum sativum L.) was decrypted for knowledge-based flavor optimization of new food products containing pea protein. Sensomics helped to determine several volatiles via ultra-high performance liquid chromatography tandem mass spectrometry and 3-nitrophenylhydrazine derivatization. Among the investigated volatiles, representatives of aldehydes, ketones, and acids were reported in literature as especially important in pea and pea-related matrices. After validation of the method and quantitation of the corresponding analytes, sensory reconstitution as well as omission studies of a selected pea protein were performed and revealed nine odor-active compounds as key food odorants (3-methylbutanal, hexanal, acetaldehyde, (E,E)-2,4-nonadienal, (E)-2-octenal, benzaldehyde, heptanal, 2-methylbutanal, and nonanoic acid). Interestingly, eight out of nine compounds belonged to the chemical class of aldehydes. Statistical heatmap and cluster analysis of all odor activity values of different pea proteins confirmed the obtained sensory results and generalize these nine key food odorants in other pea proteins. The knowledge of key components gained shows potential for simplifying industrial flavor optimization of pea protein-based food.
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Affiliation(s)
- Florian Utz
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany; (F.U.); (A.S.); (T.D.S.); (T.H.)
| | - Andrea Spaccasassi
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany; (F.U.); (A.S.); (T.D.S.); (T.H.)
| | - Johanna Kreissl
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany;
| | - Timo D. Stark
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany; (F.U.); (A.S.); (T.D.S.); (T.H.)
| | - Caren Tanger
- Chair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, Weihenstephaner Berg 1, 85354 Freising, Germany; (C.T.); (U.K.)
| | - Ulrich Kulozik
- Chair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, Weihenstephaner Berg 1, 85354 Freising, Germany; (C.T.); (U.K.)
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany; (F.U.); (A.S.); (T.D.S.); (T.H.)
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany; (F.U.); (A.S.); (T.D.S.); (T.H.)
- Correspondence: ; Tel.: +49-81-6171-2901
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14
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Abramov A, Hoffmann T, Stark TD, Zheng L, Lenk S, Hammerl R, Lanzl T, Dawid C, Schön CC, Schwab W, Gierl A, Frey M. Engineering of benzoxazinoid biosynthesis in Arabidopsis thaliana: Metabolic and physiological challenges. Phytochemistry 2021; 192:112947. [PMID: 34534712 DOI: 10.1016/j.phytochem.2021.112947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/29/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Plant specialised metabolites constitute a layer of chemical defence. Classes of the defence compounds are often restricted to a certain taxon of plants, e.g. benzoxazinoids (BX) are characteristically detected in grasses. BXs confer wide-range defence by controlling herbivores and microbial pathogens and are allelopathic compounds. In the crops maize, wheat and rye high concentrations of BXs are synthesised at an early developmental stage. By transfer of six Bx-genes (Bx1 to Bx5 and Bx8) it was possible to establish the biosynthesis of 2,4-dihydroxy-1,4-benzoxazin-3-one glucoside (GDIBOA) in a concentration of up to 143 nmol/g dry weight in Arabidopsis thaliana. Our results indicate that inefficient channeling of substrates along the pathway and metabolisation of intermediates in host plants might be a general drawback for transgenic establishment of specialised metabolite biosynthesis pathways. As a consequence, BX levels required for defence are not obtained in Arabidopsis. We could show that indolin-2-one (ION), the first specific intermediate, is phytotoxic and is metabolised by hydroxylation and glycosylation by a wide spectrum of plants. In Arabidopsis, metabolic stress due to the enrichment of ION leads to elevated levels of salicylic acid (SA) and in addition to its intrinsic phytotoxicity, ION affects plant morphology indirectly via SA. We could show that Bx3 has a crucial role in the evolution of the pathway, first based on its impact on flux into the pathway and, second by C3-hydroxylation of the phytotoxic ION. Thereby BX3 interferes with a supposedly generic detoxification system towards the non-specific intermediate.
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Affiliation(s)
- Aleksej Abramov
- Chair of Plant Breeding, Technical University of Munich, Liesel-Beckman Str. 2, 85354, Freising, Germany
| | - Thomas Hoffmann
- Associate Professorship of Biotechnology of Natural Products, Technical University of Munich, Liesel-Beckmann Str. 1, 85354, Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner Str. 34, 85354, Freising, Germany
| | - Linlin Zheng
- Chair of Genetics, Technical University of Munich, Emil-Ramann Str. 8, 85354, Freising, Germany
| | - Stefan Lenk
- Chair of Genetics, Technical University of Munich, Emil-Ramann Str. 8, 85354, Freising, Germany
| | - Richard Hammerl
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner Str. 34, 85354, Freising, Germany
| | - Tobias Lanzl
- Chair of Plant Breeding, Technical University of Munich, Liesel-Beckman Str. 2, 85354, Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner Str. 34, 85354, Freising, Germany
| | - Chris-Carolin Schön
- Chair of Plant Breeding, Technical University of Munich, Liesel-Beckman Str. 2, 85354, Freising, Germany
| | - Wilfried Schwab
- Associate Professorship of Biotechnology of Natural Products, Technical University of Munich, Liesel-Beckmann Str. 1, 85354, Freising, Germany
| | - Alfons Gierl
- Chair of Genetics, Technical University of Munich, Emil-Ramann Str. 8, 85354, Freising, Germany
| | - Monika Frey
- Chair of Plant Breeding, Technical University of Munich, Liesel-Beckman Str. 2, 85354, Freising, Germany.
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15
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Walser V, Kranzler M, Dawid C, Ehling-Schulz M, Stark TD, Hofmann TF. Distribution of the Emetic Toxin Cereulide in Cow Milk. Toxins (Basel) 2021; 13:toxins13080528. [PMID: 34437398 PMCID: PMC8402402 DOI: 10.3390/toxins13080528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 12/21/2022] Open
Abstract
Bacillus cereus is frequently associated with food-borne intoxications, and its emetic toxin cereulide causes emesis and nausea after consumption of contaminated foods. The major source for contamination is found within contaminated raw materials containing the highly chemically resistant cereulide, independent of vegetative bacteria cells. Up to date, non-existing removal strategies for cereulide evoke the question of how the toxin is distributed within a food sample, especially cow milk. Milk samples with different milk fat contents were incubated with purified cereulide, separated by centrifugation into a lipid and an aqueous phase, and cereulide was quantified in both fractions by SIDA-LC-MS/MS. By artificially increasing the milk fat content from 0.5% to 50%, the amount of cereulide recovered in the lipid phase and could be augmented from 13.3 to 78.6%. Further, the ratio of cereulide increased in the lipid phase of milk with additional plant-based lipid (sunflower oil) to 47.8%. This demonstrated a clear affinity of cereulide towards the hydrophobic, lipid phase, aligning with cereulide's naturally strong hydrophobic properties. Therefore, an intensified cereulide analysis of lipid enriched dairy products to prevent severe cereulide intoxications or cross-contamination in processed foods is suggested.
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Affiliation(s)
- Veronika Walser
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
| | - Markus Kranzler
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Corinna Dawid
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Timo D. Stark
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
- Correspondence: ; Tel.: +49-8161-71-2911
| | - Thomas F. Hofmann
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
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16
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Samfaß J, Stark TD, Hofmann TF. Sensory-Directed Identification of Creaminess-Enhancing Semi-Volatile Lactones in Crumb Chocolate. Foods 2021; 10:foods10071483. [PMID: 34202281 PMCID: PMC8306539 DOI: 10.3390/foods10071483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022] Open
Abstract
In order to gain a more comprehensive knowledge of the chemical nature of creaminess-related flavor compounds in milk chocolates on a molecular level, crumb chocolate was analyzed by means of activity guided screening techniques. Sensory studies of a triglyceride-free lipid emulsion indicated that the n-pentane extract showed the highest impact regarding creaminess sensation. Enhancement of creaminess by adding anhydrous milk fat fractions to chocolate was demonstrated by fractionated high-vacuum distillation of different fats associated with the chocolate production combined with sensory experiments. Syntheses of various δ-lactones and the quantification of these sensory active semi-volatiles led to the conclusion that the anhydrous milk fat contains a series of γ- and δ-lactones. Cocoa butter revealed a high concentration of δ-hexadecalactone, too. Experiments suggested that lactones are generated from the potential precursors monohydroxyalkanoic acid(s) esterified (mono-tri)glyceride(s) during heating. Sensory studies exhibited recognition thresholds of 29–40 µmol/kg for the long-chain δ-lactones in crumb chocolate. Furthermore, significant enhancement of the retro-nasal creamy flavor was found for δ-tetradecalactone.
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Affiliation(s)
| | - Timo D. Stark
- Correspondence: ; Tel.: +49-8161-71-2911; Fax: +49-8161-71-2949
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17
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Schmid C, Brockhoff A, Shoshan-Galeczki YB, Kranz M, Stark TD, Erkaya R, Meyerhof W, Niv MY, Dawid C, Hofmann T. Comprehensive structure-activity-relationship studies of sensory active compounds in licorice (Glycyrrhiza glabra). Food Chem 2021; 364:130420. [PMID: 34182369 DOI: 10.1016/j.foodchem.2021.130420] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 11/26/2022]
Abstract
Licorice saponins, the main constituents of Glycyrrhiza glabra L. roots, are highly appreciated by the consumer for their pleasant sweet and long lasting licorice taste. The objective of the present study was to understand the molecular features that contribute to bitter, sweet and licorice sensation of licorice roots, and whether individual compounds elicit more than one of these sensations. Therefore, a sensomics approach was conducted, followed by purification of the compounds with highest sensory impact, and by synthesis as well as full characterization via HRESIMS, ESIMS/MS and 1D/2D-NMR experiments. This led to the discovery and structure determination of 28 sweet, bitter and licorice tasting key phytochemicals, including two unknown compounds. A combination of sensorial, cell-based and computational analysis revealed distinct structural features, such as spatial arrangement of functional groups in the triterpenoid E-ring, driving to different taste sensations and sweet receptor hTAS1R2/R3 stimulation.
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Affiliation(s)
- Christian Schmid
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Anne Brockhoff
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Yaron Ben Shoshan-Galeczki
- The Institute of Biochemistry, Food and Nutrition, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University, 76100 Rehovot and The Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem 91904, Israel
| | - Maximilian Kranz
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Rukiye Erkaya
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Wolfgang Meyerhof
- German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; Center for Integrative Physiology and Molecular Medicine, Saarland University, Kirrberger Straße 100, 66421 Homburg, Germany
| | - Masha Y Niv
- The Institute of Biochemistry, Food and Nutrition, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University, 76100 Rehovot and The Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem 91904, Israel
| | - Corinna Dawid
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany.
| | - Thomas Hofmann
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany.
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18
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Utz F, Kreissl J, Stark TD, Schmid C, Tanger C, Kulozik U, Hofmann T, Dawid C. Sensomics-Assisted Flavor Decoding of Dairy Model Systems and Flavor Reconstitution Experiments. J Agric Food Chem 2021; 69:6588-6600. [PMID: 34085519 DOI: 10.1021/acs.jafc.1c02165] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The whole sensometabolome of a typical dairy milk dessert was decoded to potentially serve as a blueprint for further flavor optimization steps of functional fat-reduced food. By applying the sensomics approach, a wide range of different dairy volatiles, semi and nonvolatiles, were analyzed by ultrahigh-performance liquid chromatography tandem mass spectrometry with or without derivatization presteps. While for volatile sulfur compounds with low odor thresholds, headspace solid-phase microextraction gas chromatography was established, abundant carbohydrates and organic acids were quantified by quantitative 1H nuclear magnetic resonance spectroscopy. Validated quantitation, sensory reconstitution, and omission studies highlighted eight flavor-active compounds, namely, diacetyl, δ-tetra-, δ-hexa-, and δ-octadecalactone, sucrose, galactose, lactic acid, and citric acid as indispensable for flavor recombination. Furthermore, eight odorants (acetaldehyde, acetic acid, butyric acid, methanethiol, phenylacetic acid, dimethyl sulfide, acetoin, and hexanoic acid), all with odor activity values >1, additionally contributed to the overall flavor blueprint. Within this work, a dairy flavor analytical toolbox covering four different high-throughput methods could successfully be established showing potential for industrial applications.
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Affiliation(s)
- Florian Utz
- Chair for Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Johanna Kreissl
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Timo D Stark
- Chair for Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Christian Schmid
- Chair for Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Caren Tanger
- Chair for Food and Bioprocess Engineering, Technical University of Munich, Weihenstephaner Berg 1, Freising 85354, Germany
| | - Ulrich Kulozik
- Chair for Food and Bioprocess Engineering, Technical University of Munich, Weihenstephaner Berg 1, Freising 85354, Germany
| | - Thomas Hofmann
- Chair for Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Corinna Dawid
- Chair for Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
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19
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Walser V, Kranzler M, Ehling-Schulz M, Stark TD, Hofmann TF. Structure Revision of Isocereulide A, an Isoform of the Food Poisoning Emetic Bacillus cereus Toxin Cereulide. Molecules 2021; 26:molecules26051360. [PMID: 33806334 PMCID: PMC7961578 DOI: 10.3390/molecules26051360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022] Open
Abstract
The emetic Bacillus cereus toxin cereulide presents an enormous safety hazard in the food industry, inducing emesis and nausea after the consumption of contaminated foods. Additional to cereulide itself, seven structurally related isoforms, namely the isocereulides A–G, have already been elucidated in their chemical structure and could further be identified in B. cereus contaminated food samples. The newly performed isolation of isocereulide A allowed, for the first time, 1D- and 2D-NMR spectroscopy of a biosynthetically produced isocereulide, revealing results that contradict previous assumptions of an l-O-Leu moiety within its chemical structure. By furthermore applying posthydrolytical dipeptide analysis, amino acid and α-hydroxy acid analysis by means of UPLC-ESI-TOF-MS, as well as MSn sequencing, the structure of previously reported isocereulide A could be corrected. Instead of the l-O-Leu as assumed to date, one l-O-Ile unit could be verified in the cyclic dodecadepsipeptide, revising the structure of isocereulide A to [(d-O-Leu-d-Ala-l-O-Val-l-Val)2(d-O-Leu-d-Ala-l-O-Ile-l-Val)].
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Affiliation(s)
- Veronika Walser
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (T.F.H.)
| | - Markus Kranzler
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Timo D. Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (T.F.H.)
- Correspondence: ; Tel.: +49-8161-71-2911
| | - Thomas F. Hofmann
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (T.F.H.)
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20
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Kalbhenn EM, Bauer T, Stark TD, Knüpfer M, Grass G, Ehling-Schulz M. Detection and Isolation of Emetic Bacillus cereus Toxin Cereulide by Reversed Phase Chromatography. Toxins (Basel) 2021; 13:toxins13020115. [PMID: 33557428 PMCID: PMC7915282 DOI: 10.3390/toxins13020115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/30/2021] [Accepted: 02/01/2021] [Indexed: 12/17/2022] Open
Abstract
The emetic toxin cereulide is a 1.2 kDa dodecadepsipeptide produced by the food pathogen Bacillus cereus. As cereulide poses a serious health risk to humans, sensitive and specific detection, as well as toxin purification and quantification, methods are of utmost importance. Recently, a stable isotope dilution assay tandem mass spectrometry (SIDA–MS/MS)-based method has been described, and an method for the quantitation of cereulide in foods was established by the International Organization for Standardization (ISO). However, although this SIDA–MS/MS method is highly accurate, the sophisticated high-end MS equipment required for such measurements limits the method’s suitability for microbiological and molecular research. Thus, we aimed to develop a method for cereulide toxin detection and isolation using equipment commonly available in microbiological and biochemical research laboratories. Reproducible detection and relative quantification of cereulide was achieved, employing reversed phase chromatography (RPC). Chromatographic signals were cross validated by ultraperformance liquid chromatography–mass spectrometry (UPLC–MS/MS). The specificity of the RPC method was tested using a test panel of strains that included non-emetic representatives of the B. cereus group, emetic B. cereus strains, and cereulide-deficient isogenic mutants. In summary, the new method represents a robust, economical, and easily accessible research tool that complements existing diagnostics for the detection and quantification of cereulide.
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Affiliation(s)
- Eva Maria Kalbhenn
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
| | - Tobias Bauer
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
| | - Timo D. Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany;
| | - Mandy Knüpfer
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937 Munich, Germany; (M.K.); (G.G.)
| | - Gregor Grass
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937 Munich, Germany; (M.K.); (G.G.)
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
- Correspondence:
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Nyavor Y, Brands CR, Nicholson J, Kuther S, Cox KK, May G, Miller C, Yasuda A, Potter F, Cady J, Heyman HM, Metz TO, Stark TD, Hofmann T, Balemba OB. Supernatants of intestinal luminal contents from mice fed high-fat diet impair intestinal motility by injuring enteric neurons and smooth muscle cells. Neurogastroenterol Motil 2021; 33:e13990. [PMID: 32969549 DOI: 10.1111/nmo.13990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 08/12/2020] [Accepted: 08/25/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Damage to enteric neurons and impaired gastrointestinal muscle contractions cause motility disorders in 70% of diabetic patients. It is thought that enteric neuropathy and dysmotility occur before overt diabetes, but triggers of these abnormalities are not fully known. We tested the hypothesis that intestinal contents of mice with and without high-fat diet- (HFD-) induced diabetic conditions contain molecules that impair gastrointestinal movements by damaging neurons and disrupting muscle contractions. METHODS Small and large intestinal segments were collected from healthy, standard chow diet (SCD) fed mice. Filtrates of ileocecal contents (ileocecal supernatants; ICS) from HFD or SCD mice were perfused through them. Cultured intact intestinal muscularis externa preparations were used to determine whether ICS and their fractions obtained by solid-phase extraction (SPE) and SPE subfractions collected by high-performance liquid chromatography (HPLC) disrupt muscle contractions by injuring neurons and smooth muscle cells. KEY RESULTS ICS from HFD mice reduced intestinal motility, but those from SCD mice had no effect. ICS, aqueous SPE fractions and two out of twenty HPLC subfractions of aqueous SPE fractions from HFD mice blocked muscle contractions, caused a loss of nitrergic myenteric neurons through inflammation, and reduced smooth muscle excitability. Lipopolysaccharide and palmitate caused a loss of nitrergic myenteric neurons but did not affect muscle contractions. CONCLUSIONS & INFERENCES Unknown molecules in intestinal contents of HFD mice trigger enteric neuropathy and dysmotility. Further studies are required to identify the toxic molecules and their mechanisms of action.
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Affiliation(s)
- Yvonne Nyavor
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | | | - Jessica Nicholson
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Sydney Kuther
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Kortni K Cox
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - George May
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | | | - Allysha Yasuda
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Forrest Potter
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Joshua Cady
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Heino M Heyman
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Thomas O Metz
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, Freising, Germany
| | - Thomas Hofmann
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, Freising, Germany
| | - Onesmo B Balemba
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
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22
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Edelmann M, Dawid C, Ralla T, Stark TD, Salminen H, Weiss J, Hofmann T. Fast and Sensitive LC-MS/MS Method for the Quantitation of Saponins in Various Sugar Beet Materials. J Agric Food Chem 2020; 68:15027-15035. [PMID: 33259191 DOI: 10.1021/acs.jafc.0c05836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
An LC-MS/MS method was developed for the simultaneous quantitative analysis of the following 11 triterpene saponins within different sugar beet materials and plant compartments: betavulgaroside I (1), betavulgaroside II (2), betavulgaroside III (3), betavulgaroside IV (4), betavulgaroside VIII (5), boussingoside A2 (6), 3-O-[β-d-glucopyranosyl-(1 → 2)-(β-d-xylopyranosyl-(1 → 3))-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid (7), betavulgaroside V (8), chikusetsusaponin IVa (9), calenduloside E (10), and ginsenoside R0 (11). Our results showed highly varying amounts of saponins within different varieties, roots, and leaves as well as different plant compartments. The amounts for sugar beet roots were in the range of 862 mg/kg to 2 452 mg/kg. They were mostly higher for leaves compared to roots of the same variety with amounts ranging from 907 mg/kg to 5 398 mg/kg. Furthermore, the occurrence of sugar beet saponins within different side streams was examined; in this context, sugar beet fiber contained the highest amounts of saponins for all investigated plant constituents and byproduct streams with a total amount of 12.7 g/kg. Finally, this is the first publication about the occurrence of individual saponins in sugar beets.
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Affiliation(s)
- Matthias Edelmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany
| | - Theo Ralla
- Department of Food Material Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
| | - Hanna Salminen
- Department of Food Material Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Jochen Weiss
- Department of Food Material Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
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Stark TD, Rami J, Fröhlich S, Weiss P, Vierling W, Dongmo AB, Hofmann T. A new phytoecdysteroid from the stem bark of Vitex cienkowskii. Eur Food Res Technol 2020. [DOI: 10.1007/s00217-020-03591-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractTo investigate differences in the metabolome of the stem bark of Vitex cienkowskii harvested at three different locations and three different seasons, their extracts were analyzed by means of UPLC–ESI–IMS–TOF MSe. One marker metabolite was isolated and chemically characterized, which was identified as the new compound 20,24-dihydroxy,24-hydroxymethylecdysone (1). IMS showed two drift time species for 1 which could be used as new and additional characteristic compound parameters in compound identification to reduce dereplication and false positives.
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Doellinger J, Schneider A, Stark TD, Ehling-Schulz M, Lasch P. Evaluation of MALDI-ToF Mass Spectrometry for Rapid Detection of Cereulide From Bacillus cereus Cultures. Front Microbiol 2020; 11:511674. [PMID: 33329410 PMCID: PMC7709880 DOI: 10.3389/fmicb.2020.511674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
Bacillus cereus plays an often unrecognized role in food borne diseases. Food poisoning caused by this pathogen is manifested by either diarrhea or emesis. Due to the relatively high prevalence of emetic toxin cereulide associated food poisoning, methods for simple and reliable detection of cereulide producing strains are of utmost importance. Recently, two different studies reported on the application of MALDI-ToF MS for either the differentiation of emetic and non-emetic strains of B. cereus or for direct detection of cereulide from bacterial colony smears. However, for implementation of cereulide detection using MALDI-ToF MS in routine microbiological diagnostics additional investigations on the sensitivity and specificity as well as on the fitting into common workflows for bacterial identification are needed. These aspects prompted us to investigate open issues and to test sample preparation methods, commonly used for microbial identification for their suitability to detect the emetic toxin from bacteria. Based on our experimental findings we propose a workflow that allows identification of B. cereus and sensitive detection of cereulide in parallel, using linear-mode MALDI-ToF MS equipment. The protocol was validated in a blinded study and is based on the well-established ethanol/formic acid extraction method. Cereulide is detected in the ethanol wash solution of samples identified as B. cereus as peaks at m/z 1175 and 1191. Peak position difference of 16 Th (Thomson) indicates detection of the sodium and potassium adducts of cereulide. This sample treatment offers possibilities for further characterization by more sophisticated LC-MS-based methods. In summary, the ease of use and the achieved level of analytical sensitivity as well as the wide-spread availability of MALDI-ToF MS equipment in clinical microbiological laboratories provides a promising tool to improve and to facilitate routine diagnostics of B. cereus associated food intoxications.
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Affiliation(s)
- Joerg Doellinger
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
| | - Andy Schneider
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Munich, Germany
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Peter Lasch
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
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Edelmann M, Dawid C, Hochreiter K, Ralla T, Stark TD, Salminen H, Weiss J, Hofmann T. Molecularization of Foam-Active Saponins from Sugar Beet Side Streams ( Beta vulgaris ssp. vulgaris var. altissima). J Agric Food Chem 2020; 68:10962-10974. [PMID: 32881499 DOI: 10.1021/acs.jafc.0c04603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This work focuses on the isolation and characterization of saponins with a very low bitter intensity originating from sustainable plant materials, in particular the sugar beet pulp by-product stream. Via a concise foam activity screening of saponin-containing materials, which gives indications for their emulsifying ability, sugar beet root extract was selected and examined for low bitter saponins by means of activity guided fractionation. Individual saponins were isolated from sugar beet pulp, which was identified as the most convenient sugar beet saponin source. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy led to the unequivocal identification of the major, slightly bitter tasting compounds as a series of eight saponins. The complete assignment of 1H and 13C NMR signals for several saponins was carried out for the first time. A small-scale foam activity assay was established and applied to a broad spectrum of the isolated and commercially available saponins. Additionally, orosensory recognition thresholds were determined. Not only high recognition thresholds were determined (thresholds >1000 μmol/L) but also fundamental information about the foaming behavior of mono- and bidesmosidic saponins was collected. The obtained results are relevant to the utilization of saponins from other plant materials or by-product streams and for the use of sugar beet saponins as food additives.
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Affiliation(s)
- Matthias Edelmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany
| | - Katharina Hochreiter
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Theo Ralla
- Department of Food Physics and Meat Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Hanna Salminen
- Department of Food Physics and Meat Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Jochen Weiss
- Department of Food Physics and Meat Science, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
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Germann D, Stark TD, Hofmann T. Formation and Characterization of Polyphenol-Derived Red Chromophores. Enhancing the Color of Processed Cocoa Powders: Part 2. J Agric Food Chem 2019; 67:4643-4651. [PMID: 30963759 DOI: 10.1021/acs.jafc.9b01050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Very recently, we described the formation of (+)-catechin- and (-)-epicatechin-derived polar chromophores by means of a cocoa alkalization process. In this study we focus on the generation of unpolar chromophores using model reactions via Dutching with softer alkaline conditions. UPLC-HR-ESI-TOF-MSe analysis and one-dimensional and two-dimensional NMR spectroscopy led to the unequivocal identification of dehydrodicatechin- and hydroxyxanthene-derived chromophores. The previously unknown 6- C-linked constitutional isomers of C-6'B/C-6D-(2 R,3 S)-dehydrodicatechin (3, 5) were first described, and furthermore, the dimers dehydrocatechin-C-6'B/C-8D-(2 S,3 S)-epicatechin (2) and dehydrocatechin-C-6'B/C-6D-(2 S,3 S)-epicatechin (4, 6) as well as the reddish-colored chromophores 8- C-xanthenocatechin (7), 8- C-xanthenoepicatechin (8), 6- C-xanthenocatechin (9), and 6- C-xanthenoepicatechin (10) were identified as new compounds. A LC-MS/MS method was developed to screen and quantify both classes of chromophores as well as their precursors in alkalized cocoa powders. The dehydrocatechin dimers showed degradation via the alkalization process; in contrast, the xanthenocatechins highlighted an increase in concentration with stronger alkalization, and, therefore, contribute to cocoa reddening. These results, together with those previously published, give a clear insight into the chemistry of polyphenol-derived chromophores generated by cocoa powder alkalization and enable a better understanding of chromophore formation mechanisms toward a more comprehensive color design of cocoa powders.
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Affiliation(s)
- Daniel Germann
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
| | - Thomas Hofmann
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
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Germann D, Stark TD, Hofmann T. Formation and Characterization of Polyphenol-Derived Red Chromophores. Enhancing the Color of Processed Cocoa Powders: Part 1. J Agric Food Chem 2019; 67:4632-4642. [PMID: 30901211 DOI: 10.1021/acs.jafc.9b01049] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Although cocoa powder alkalization (Dutching) is a widely used industrial process to improve taste, dispersibility, and coloring of the final product, nevertheless knowledge about the compounds causing a change in coloring is fragmentary. By means of alkaline model reactions starting from the major cocoa polyphenol monomers, (+)-catechin or (-)-epicatechin, eight chromophores were derived from the first rearrangement product catechinic acid. LC-MS/MS analysis, one- and two dimensional-NMR, and electron paramagnetic resonance (EPR) spectroscopy led to the unequivocal identification of 6'-hydroxycatechinic acids (1a, 2a) and their radical states (1b, 2b), which were highlighted as main red chromophores. Six new dehydrocatechinic acid dimers (dehydrocatechinic acid-C-6'B/C-8D-(2 R,3 S)-catechin (3), dehydrocatechinic acid-C-6'B/C-6D-(2 R,3 S)-catechin (4, 5), dehydrocatechinic acid-C-6'B/C-8D-(2 R,3 R)-epicatechin (6), and dehydrocatechinic acid-C-6'B/C-6D-(2 R,3 R)-epicatechin (7, 8)) were also characterized as chromophores. 1-8 as well as their precursors were detected and quantified in alkalized cocoa powders via LC-MS/MS. With the increasing grade of alkalization, a decrease in catechin and epicatechin together with an increase in catechinic acid was observed. Compounds 1b, 2b, and 3-8 also showed a decrease in concentration by Dutching, which correlates to the accumulation of/to higher ordered chromophore oligomers and underlined the increase of the high molecular weight fraction. These findings give a first insight into the formation of structures causing the red coloring of cocoa, which offers the opportunity to optimize the alkalization process toward a better color design of cocoa powders.
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Affiliation(s)
- Daniel Germann
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
| | - Thomas Hofmann
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Strasse 34 , 85354 , Freising , Germany
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Abstract
Activity-guided fractionation of an aqueous extract of overfermented cocoa beans, which were recently found to be a rich source of previously unknown taste enhancing substances, revealed the presence of a series of taste modulating short peptides. Fractionation was achieved by means of sequential solvent extraction, medium pressure liquid chromatography, as well as preparative high pressure liquid chromatography, and the taste modulating activity was determined by means of matrix assisted taste dilution analysis. By means of ultra performance liquid chromatography-time-of-flight-mass spectrometry (UPLC-ToF-MS) screening, liquid chromatography-MS/MS methods, and customized syntheses, numerous short peptides could be identified in the taste modulating fractions. Sensory experiments of the target peptides showed umami enhancing and salt taste enhancing properties as well as kokumi effects when applied in a savory taste matrix. Evaluation of the taste threshold concentrations in model broth demonstrated a high taste modulating potential of 11 out of 13 identified peptides. Lowest threshold concentrations were determined for the salt taste enhancing tripeptide pEEE (55 μmol/L) and the kokumi active tripeptide VPA (90 μmol/L). Furthermore, a large number of dipeptides, carrying either a prolyl- or pyro-glutamyl moiety were located in the aqueous extract, exhibiting taste modulating properties and revealing a pH dependency of the taste modulating effect of the savory taste matrix. Additionally, synergistic effects of a mixture of five umami enhancing pyro-glutamyl dipeptides in the model matrix were demonstrated.
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Affiliation(s)
- Mathias Salger
- Food Chemistry and Molecular and Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 84354 Freising , Germany
| | - Timo D Stark
- Food Chemistry and Molecular and Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 84354 Freising , Germany
| | - Thomas Hofmann
- Food Chemistry and Molecular and Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 84354 Freising , Germany
- Bavarian Center for Biomolecular Mass Spectrometry , Gregor-Mendel-Straße 4 , 85354 Freising , Germany
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Abstract
A powder formulation of aged garlic extract was heated at 100 °C for 1 day to obtain higher antioxidant activity determined with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging (ARS) and oxygen radical absorbance capacity (ORAC) assays. Activity-guided fractionation afforded 12 new in vitro antioxidative Maillard-type products, α-[(2-formyl-5-hydroxymethyl)pyrrol-1-yl]arginine (3), 4-[7-hydroxy-6-(hydroxymethyl)-7,8-dihydro-6 H-pyrano[2,3- b] pyrazine-3-yl]butane-1,2,3-triol (4), 4-[6-(1,2-dihydroxyethyl)-6,7-dihydro-furo[2,3- b]pyrazin-3-yl]-butane-1,2,3-triol (5), α-[(2-formyl-5-hydroxymethyl)-pyrrol-1-yl] aspartic acid (12), 1-[5-(1,2-dihydroxyethyl)-2-oxotetrahydrofuran-3-yl]-5-(hydroxymethyl)-1 H-pyrrole-2-carbaldehyde (14), 4-(6-ethyl-2-pyrazinyl)-1,2,3-butanetriol (17), α-[(2-formyl-5-hydroxymethyl)pyrrol-1-yl] glutamic acid (19), ( S)-1-[(5-hydroxymethyl)furan-2-yl]methyl]-5-oxopyrrolidine-2-carboxylic acid (20), 3-hydroxy-1 H-[{5-(hydroxymethyl)furan-2-yl}methyl]-2,5-dioxo-3-pyrrolidine acetic acid (21), ( E)-4-(5-methylpyrazin-2-yl)but-3-ene-7,2-diol (23), 4-acetyl-6-(hydroxymethyl)picolinic acid (24), ( E)-4-(6-methylpyrazin-2-yl)but-3-ene-1,2-diol (26) and 14 known compounds, 1, 2, 6-11, 13, 15, 16, 18, 22 and 25, which were characterized via 1D/2D-NMR, CD spectroscopy, and mass spectrometry. ARS and ORAC activities of these antioxidants ranged from 0.01 to 0.49 μmol TE/μmol and from 0.01 to 3.50 μmol TE/μmol, respectively. Additionally, plausible formation pathways for the new organic acid-type products (15, 20, and 21) were proposed based on proving their generation in model reactions detected via liquid chromatography-mass spectrometry (LC-MS/MS).
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Affiliation(s)
- Junichiro Wakamatsu
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 85354 Freising , Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 85354 Freising , Germany
| | - Thomas Hofmann
- Food Chemistry and Molecular Sensory Science , Technische Universität München , Lise-Meitner-Straße 34 , 85354 Freising , Germany
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Stark TD, Ranner J, Stiglbauer B, Weiss P, Stark S, Balemba OB, Hofmann T. Construction and Application of a Database for a Five-Dimensional Identification of Natural Compounds in Garcinia Species by Means of UPLC-ESI-TWIMS-TOF-MS: Introducing Gas Phase Polyphenol Conformer Drift Time Distribution Intensity Ratios. J Agric Food Chem 2019; 67:975-985. [PMID: 30576604 DOI: 10.1021/acs.jafc.8b06157] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thirty-four reference compounds from G. buchananii were analyzed by means of UPLC-ESI-IMS-TOF-MS to build a database consisting of retention time, accurate m/ z of precursors and fragment ions, and rotationally averaged collision cross-sectional area (CCS). The CCS value of six selected compounds analyzed in bark extract in different concentrations and solvent systems showed excellent intra- and interday precision (RSD ≤ 0.9%). The established database was applied on different organs of G. buchananii as well as G. kola, G. mangostana, and G. cambogia enabling a fast and reliable identification of these natural bioactives. For several compounds, more than one drift time species could be highlighted, which we propose to be hydrogen bond stabilized rotational isomers transferred from solution to gas phase. We used all CCS values of one compound, and we propose to add also the intensity ratio of the conformers as a new and additional characteristic compound parameter in compound identification/screening/database applications to reduce dereplication and false positives and to strengthen the identification.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Josef Ranner
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Benedikt Stiglbauer
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Patrick Weiss
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Sofie Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Onesmo B Balemba
- Department of Biological Sciences , University of Idaho , Moscow , Idaho 83844 , United States
| | - Thomas Hofmann
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
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Bauer T, Sipos W, Stark TD, Käser T, Knecht C, Brunthaler R, Saalmüller A, Hofmann T, Ehling-Schulz M. First Insights Into Within Host Translocation of the Bacillus cereus Toxin Cereulide Using a Porcine Model. Front Microbiol 2018; 9:2652. [PMID: 30464760 PMCID: PMC6234764 DOI: 10.3389/fmicb.2018.02652] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 10/17/2018] [Indexed: 11/13/2022] Open
Abstract
Bacillus cereus is a gram-positive pathogen mainly known to evoke two types of foodborne poisonings. The diarrheal syndrome is caused by enterotoxins produced during growth in the intestine. In contrast, the emetic type is caused by the dodecadepsipeptide cereulide pre-formed in food. Usually, both diseases are self-limiting but occasionally more severe forms, including fatal ones, are reported. Since the mechanisms of cereulide toxin uptake and translocation within the body as well as the mechanism of its toxic action are still unknown, we used a porcine model to investigate the uptake, routes of excretion and distribution of cereulide within the host. Pigs were orally challenged with cereulide using single doses of 10-150 μg cereulide kg-1 body weight to study acute effects or using daily doses of 10 μg cereulide kg-1 body weight administered for 7 days to investigate effects of longtime, chronic exposure. Our study showed that part of cereulide ingested with food is rapidly excreted with feces while part of the cereulide toxin is absorbed, passes through membranes and is distributed within the body. Results from the chronic trial indicate bioaccumulation of cereulide in certain tissues and organs, such as kidney, liver, muscles and fat tissues. Beside its detection in various tissues and organs, our study also demonstrated that cereulide is able to cross the blood-brain-barrier, which may partially explain the cerebral effects reported from human intoxication cases. The neurobehavioral symptoms, such as seizures and lethargy, observed in our porcine model resemble those reported from human food borne intoxications. The rapid onset of these symptoms indicates direct effects of cereulide on the central nervous system (CNS), which warrant further research. The porcine model presented here might be useful to study the specific neurobiological effect in detail. Furthermore, our study revealed that typical diagnostic specimens used in human medicine, such as blood samples and urine, are not suitable for diagnostics of food borne cereulide intoxications. Instead, screening of fecal samples by SIDA-LC-MS may represent a simple and non-invasive method for detection of cereulide intoxications in clinical settings as well as in foodborne outbreak situations.
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Affiliation(s)
- Tobias Bauer
- Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Wolfgang Sipos
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Freising, Germany
| | - Tobias Käser
- Department of Pathobiology, Institute of Immunology, University of Veterinary Medicine Vienna, Vienna, Austria.,Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University (NCSU), Raleigh, NC, United States
| | - Christian Knecht
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Rene Brunthaler
- Department of Pathobiology, Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Armin Saalmüller
- Department of Pathobiology, Institute of Immunology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Freising, Germany
| | - Monika Ehling-Schulz
- Department of Pathobiology, Functional Microbiology, Institute of Microbiology, University of Veterinary Medicine Vienna, Vienna, Austria
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Matsutomo T, Stark TD, Hofmann T. Targeted screening and quantitative analyses of antioxidant compounds in aged-garlic extract. Eur Food Res Technol 2018. [DOI: 10.1007/s00217-018-3092-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Acharya S, Stark TD, Oh ST, Jeon S, Pak SC, Kim M, Hur J, Matsutomo T, Hofmann T, Hill RA, Balemba OB. (2R,3S,2″R,3″R)-Manniflavanone Protects Proliferating Skeletal Muscle Cells against Oxidative Stress and Stimulates Myotube Formation. J Agric Food Chem 2017; 65:3636-3646. [PMID: 28430433 DOI: 10.1021/acs.jafc.6b05161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigated the antioxidative properties of (2R,3S,2″R,3″R)-manniflavanone (MF) using in vitro assays and examined its effects on myogenesis and lactate-induced oxidative stress in C2C12 cells. MF was purified from Garcinia buchananii stem bark. H2O2 and oxygen radical absorbance capacity assays demonstrated that MF is a powerful antioxidant. This finding was supported by diphenylpicrylhydrazine radical scavenging activity of MF. MF was less cytotoxic to C2C12 cells compared to ascorbic acid and myricetin. Moreover, MF accelerated myotube formation in the differentiated C2C12 cells by up-regulating myogenic proteins such as MyoG and myosin heavy chain. Furthermore, MF rescued late differentiation of myoblast suppressed by lactate treatment and up-regulated the expression levels of Nrf2 in lactate-induced oxidative stress, indicating that MF stimulates antioxidative activity inside C2C12 cells. Collectively, MF is a potent antioxidant with a higher safety profile than ascorbic acid and myricetin. It reduces oxidative stress-induced delaying of skeletal muscle differentiation by scavenging reactive oxygen species and regulating myogenic proteins factors.
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Affiliation(s)
- Suresh Acharya
- Department of Animal and Veterinary Science, University of Idaho , Moscow, Idaho 83844, United States
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
| | - Seung Tack Oh
- Research Institute, Dongkwang Pharmaceutical Company, Ltd. , Toegye-ro, Jung-gu, Seoul 04535, Republic of Korea
| | - Songhee Jeon
- Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University , Gwangju 61469, Republic of Korea
| | - Sok Cheon Pak
- School of Biomedical Sciences, Charles Sturt University , Bathurst, New South Wales 2795, Australia
| | - Mina Kim
- Korea Food Research Institute , Sungnamsi 13539, Republic of Korea
| | - Jinyoung Hur
- Korea Food Research Institute , Sungnamsi 13539, Republic of Korea
| | - Toshiaki Matsutomo
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
| | - Rodney A Hill
- Department of Animal and Veterinary Science, University of Idaho , Moscow, Idaho 83844, United States
- School of Biomedical Sciences, Charles Sturt University , Bathurst, New South Wales 2795, Australia
| | - Onesmo B Balemba
- Department of Biological Sciences, University of Idaho , Moscow, Idaho 83844, United States
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Jarolim K, Del Favero G, Ellmer D, Stark TD, Hofmann T, Sulyok M, Humpf HU, Marko D. Dual effectiveness of Alternaria but not Fusarium mycotoxins against human topoisomerase II and bacterial gyrase. Arch Toxicol 2016; 91:2007-2016. [PMID: 27682608 PMCID: PMC5364253 DOI: 10.1007/s00204-016-1855-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/15/2016] [Indexed: 11/28/2022]
Abstract
Type II DNA-topoisomerases (topo II) play a crucial role in the maintenance of DNA topology. Previously, fungi of the Alternaria genus were found to produce mycotoxins that target human topo II. These results implied the question why a fungus should produce secondary metabolites that target a human enzyme. In the current work, the homology between human topo II and its bacterial equivalent, gyrase, served as basis to study a potential dual inhibition of both enzymes by mycotoxins. A total of 15 secondary metabolites produced by fungi of the genera Alternaria and Fusarium were assessed for their impact on topo II of human and bacterial origin in the decatenation and the supercoiling assay, respectively. In line with the theory of dual topo II inhibition, six of the tested Alternaria mycotoxins were active against both enzymes, the dibenzo-α-pyrones alternariol (AOH) and alternariol monomethyl ether (AME), as well as the perylene-quinones altertoxin I (ATX I) and II (ATX II), alterperylenol (ALP) and stemphyltoxin III (STTX III). The Alternaria metabolites altersetin (ALN), macrosporin (MAC), altenusine (ALS) and pyrenophorol (PYR) impaired the function of human topo II, but did not show any effect on gyrase. The potency to inhibit topo II activity declined in the row STTX III (initial inhibitory concentration 10 µM) > AOH (25 µM) = AME (25 µM) = ALS (25 µM) = ATX II (25 µM) > ALN (50 µM) = ATX I (50 µM) > ALP (75 µM) = PYR (75 µM) > MAC (150 µM). Inhibition of gyrase activity was most pronounced for AOH and AME (initial inhibitory concentration 10 µM) followed by ATX II (25 µM) > ATX I = ALP = STTX III (50 µM). In contrast, none of the investigated Fusarium mycotoxins deoxynivalenol (DON), fumonisin B1, fusarin C and moniliformin, as well as the Alternaria metabolite tentoxin, had any impact on the activity of neither human nor bacterial topo II.
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Affiliation(s)
- Katharina Jarolim
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria
| | - Giorgia Del Favero
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria
| | - Doris Ellmer
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354, Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354, Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354, Freising, Germany
| | - Michael Sulyok
- Department IFA-Tulln, University of Natural Resources and Life Sciences Vienna (BOKU), 3430, Tulln, Austria
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Doris Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria.
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Abstract
In order to gain first insight into candidate Maillard reaction products formed upon thermal processing of garlic, mixtures of glucose and S-allyl-l-cysteine, the major sulfur-containing amino acid in garlic, were low-moisture heated, and nine major reaction products were isolated. LC-TOF-MS, 1D/2D NMR, and CD spectroscopy led to their identification as acortatarin A (1), pollenopyrroside A (2), epi-acortatarin A (3), xylapyrroside A (4), 5-hydroxymethyl-1-[(5-hydroxymethyl-2-furanyl)methyl]-1H-pyrrole-2-carbalde-hyde (5), 3-(allylthio)-2-(2-formyl-5-hydroxymethyl-1H-pyrrol-1-yl)propanoic acid (6), (4S)-4-(allylthiomethyl)-3,4-dihydro-3-oxo-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (7), (2R)-3-(allylthio)-2-[(4R)-4-(allylthiomethyl)-6-formyl-3-oxo-3,4-dihydropyrrolo-[1,2-a]pyrazin-2(1H)-yl]propanoic acid (8), and (2R)-3-(allylthio)-2-((4S)-4-(allylthiomethyl)-6-formyl-3-oxo-3,4-dihydropyrrolo-[1,2-a]pyrazin-2(1H)-yl)propanoic acid (9). Among the Maillard reaction products identified, compounds 5-9 have not previously been published. The thermal generation of the literature known spiroalkaloids 1-4 is reported for the first time. Sensory analysis revealed a bitter taste with thresholds between 0.5 and 785 μmol/kg for 1-5 and 7-9. Compound 6 did not show any intrinsic taste (water) but exhibited a strong mouthfullness (kokumi) enhancing activity above 186 μmol/kg. LC-MS/MS analysis showed 1-9 to be generated upon pan-frying of garlic with the highest concentration of 793.7 μmol/kg found for 6, thus exceeding its kokumi threshold by a factor of 4 and giving evidence for its potential taste modulation activity in processed garlic preparations.
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Affiliation(s)
- Junichiro Wakamatsu
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany
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Jarolim K, Del Favero G, Pahlke G, Dostal V, Zimmermann K, Heiss E, Ellmer D, Stark TD, Hofmann T, Marko D. Activation of the Nrf2-ARE pathway by the Alternaria alternata mycotoxins altertoxin I and II. Arch Toxicol 2016; 91:203-216. [PMID: 27178040 PMCID: PMC5225202 DOI: 10.1007/s00204-016-1726-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 04/27/2016] [Indexed: 01/20/2023]
Abstract
The mycotoxins altertoxin I and II (ATX I and II) are secondary metabolites produced by Alternaria alternata fungi and may occur as food and feed contaminants, especially after long storage periods. Although the toxic potential of altertoxins has been previously investigated, little is known about the pathways that play a role in their intracellular metabolism. In order to identify potential targets of ATX I and ATX II, the two toxins were tested for interaction with the nuclear factor erythroid-derived 2-like 2/antioxidant response element (Nrf2/ARE) pathway in mammalian cells. This pathway can be activated by various stressors resulting in the expression of enzymes important for metabolism and detoxification. In the present study, only ATX II triggered a concentration-dependent increase in Nrf2-ARE-dependent luciferase expression. Consistently, confocal microscopy revealed an ATX II-induced increase in Nrf2 signal in HT29 intestinal cells. In agreement with these data, ATX II induced the transcription of γ-glutamate cysteine ligase, the key enzyme in catalyzing GSH synthesis of the cells and which is regulated by Nrf2. Further investigations demonstrated that ATX II induced a concentration-dependent depletion of the cellular GSH levels after short incubation time (3 h) and an increase after longer incubation time (24 h). In conclusion, it was demonstrated that ATX II can interact at several levels of the Nrf2-ARE pathway in mammalian cells and that ATX I does not share the same mechanism of action.
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Affiliation(s)
- Katharina Jarolim
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Giorgia Del Favero
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Gudrun Pahlke
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Victoria Dostal
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Kristin Zimmermann
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Elke Heiss
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Doris Ellmer
- Chair of Food Chemistry and Molecular Sensory Science, TU München, Lise-Meitner-Straße 34, 85354, Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, TU München, Lise-Meitner-Straße 34, 85354, Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, TU München, Lise-Meitner-Straße 34, 85354, Freising, Germany
| | - Doris Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria.
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Balemba OB, Stark TD, Lösch S, Patterson S, McMillan JS, Mawe GM, Hofmann T. (2R,3S,2'' R,3''R)-manniflavanone, a new gastrointestinal smooth muscle L-type calcium channel inhibitor, which underlies the spasmolytic properties of Garcinia buchananii stem bark extract. J Smooth Muscle Res 2016; 50:48-65. [PMID: 26081368 PMCID: PMC4826780 DOI: 10.1540/jsmr.50.48] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Garcinia buchananii Baker stem bark extract (GBB) is a traditional
medication of diarrhea and dysentery in sub-Saharan Africa. It is believed that GBB causes
gastrointestinal smooth muscle relaxation. The aim of this study was to determine whether
GBB has spasmolytic actions and identify compounds underlying these actions. Calcium
(Ca2+) imaging was used to analyze the effect of GBB on Ca2+
flashes and Ca2+ waves in guinea pig gallbladder and distal colon smooth
muscle. Intracellular microelectrode recording was used to determine the effect of GBB,
six fractions of GBB, M1–5 and M7, and
(2R,3S,2”R,3”R)-manniflavanone,
a compound isolated from M3 on action potentials in gallbladder smooth muscle. The
technique was also used to analyze the effect of GBB, M3, and
(2R,3S,2”R,3”R)-manniflavanone
on action potentials in the circular muscle of mouse and guinea pig distal colons, and the
effect of GBB and
(2R,3S,2”R,3”R)-manniflavanone
on slow waves in porcine ileum. GBB inhibited Ca2+ flashes and Ca2+
waves. GBB, M3 and
(2R,3S,2”R,3”R)-manniflavanone
inhibited action potentials. L-type Ca2+ channel activator Bay K 8644 increased
the discharge of action potentials in mouse colon but did not trigger or increase action
potentials in the presence of GBB and
(2R,3S,2”R,3”R)-manniflavanone.
GBB and
(2R,3S,2”R,3”R)-manniflavanone
inhibited action potentials in the presence of Bay K 8644. GBB and
(2R,3S,2”R,3”R)-manniflavanone
reduced the amplitude but did not alter the frequency of slow waves in the porcine ileum.
In conclusion, GBB and
(2R,3S,2”R,3”R)-manniflavanone
relax smooth muscle by inhibiting L-type Ca2+ channels, thus have potential for
use as therapies of gastrointestinal smooth muscle spasms, and arrhythmias.
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Affiliation(s)
- Onesmo B Balemba
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States
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Lücking G, Frenzel E, Rütschle A, Marxen S, Stark TD, Hofmann T, Scherer S, Ehling-Schulz M. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels. Front Microbiol 2015; 6:1101. [PMID: 26528255 PMCID: PMC4602138 DOI: 10.3389/fmicb.2015.01101] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/23/2015] [Indexed: 11/13/2022] Open
Abstract
The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like megaplasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the non-ribosomal peptide synthetase (NRPS), gene inactivation- and overexpression mutants of the emetic strain F4810/72 were constructed and their impact on cereulide biosynthesis was assessed. The hydrolase CesH turned out to be a part of the complex regulatory network controlling cereulide synthesis on a transcriptional level, while the ABC transporter CesCD was found to be essential for post-translational control of cereulide synthesis. Using a gene inactivation approach, we show that the NRPS activating function of the phosphopantetheinyl transferase (PPtase) embedded in the ces locus was complemented by a chromosomally encoded Sfp-like PPtase, representing an interesting example for the functional interaction between a plasmid encoded NRPS and a chromosomally encoded activation enzyme. In summary, our results highlight the complexity of cereulide biosynthesis and reveal multiple levels of toxin formation control. ces operon internal genes were shown to play a pivotal role by acting at different levels of toxin production, thus complementing the action of the chromosomal key transcriptional regulators AbrB and CodY.
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Affiliation(s)
- Genia Lücking
- Department of Microbiology, Central Institute for Food and Nutrition Research (Zentralinstitut für Ernährungs- und Lebensmittelforschung), Technische Universität München Freising, Germany
| | - Elrike Frenzel
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna Vienna, Austria
| | - Andrea Rütschle
- Department of Microbiology, Central Institute for Food and Nutrition Research (Zentralinstitut für Ernährungs- und Lebensmittelforschung), Technische Universität München Freising, Germany
| | - Sandra Marxen
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München Freising, Germany
| | - Siegfried Scherer
- Department of Microbiology, Central Institute for Food and Nutrition Research (Zentralinstitut für Ernährungs- und Lebensmittelforschung), Technische Universität München Freising, Germany ; Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München Freising, Germany
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna Vienna, Austria
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Marxen S, Stark TD, Rütschle A, Lücking G, Frenzel E, Scherer S, Ehling-Schulz M, Hofmann T. Multiparametric Quantitation of the Bacillus cereus Toxins Cereulide and Isocereulides A-G in Foods. J Agric Food Chem 2015; 63:8307-8313. [PMID: 26352912 DOI: 10.1021/acs.jafc.5b03705] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Consumption of food products contaminated with cereulide (1), a toxin produced by Bacillus cereus, might cause intoxications with symptoms reported to range from indigestion pain and emesis to death. Recently, a series of structural variants, coined isocereulides A-G (2-8), were identified for the first time to be produced along with cereulide (1). The observation that isocereulide A (2) shows an ∼ 8-fold increased cytotoxicity when compared to 1 urges the development of analytical tools enabling an accurate quantitation of these toxins. Therefore, a rapid, sensitive, and robust stable isotope dilution assay (SIDA) was developed for the combined quantitation of 1-8 by means of UPLC-MS/MS. On average, trueness and precision of the method were 112.5 ± 1.8% RSD, repeatability and reproducibility were 2 and 4% for cereulide and isocereulides A-G, and the LOD and LOQ of 0.1 and 0.5 ng/g, respectively, demonstrated a high sensitivity for the developed SIDA method. Application of this method to food samples revealed elevated levels of 1-8 in two suspicious noodle samples, for example, ranging from 0.59 (7) to 189.08 ng/g (1) in sample 1 and from 5.77 (7) to 6198.17 ng/g (1) in sample 2, whereas the analysis of 25 randomly selected food samples, which have not been the subject to any complaints, did not contain detectable amounts of any of these toxins. As a consequence, this SIDA method could add an important contribution to the knowledge-based risk assessment of B. cereus toxins in foods.
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Affiliation(s)
| | | | | | | | - Elrike Frenzel
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna , 1210 Vienna, Austria
| | - Siegfried Scherer
- Chair of Microbial Ecology, Department of Biosciences, WZW, Technische Universität München , 85350 Freising, Germany
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna , 1210 Vienna, Austria
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Marxen S, Stark TD, Rütschle A, Lücking G, Frenzel E, Scherer S, Ehling-Schulz M, Hofmann T. Depsipeptide Intermediates Interrogate Proposed Biosynthesis of Cereulide, the Emetic Toxin of Bacillus cereus. Sci Rep 2015; 5:10637. [PMID: 26013201 PMCID: PMC4445039 DOI: 10.1038/srep10637] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/22/2015] [Indexed: 11/10/2022] Open
Abstract
Cereulide and isocereulides A-G are biosynthesized as emetic toxins by Bacillus cereus via a non-ribosomal peptide synthetase (NRPS) called Ces. Although a thiotemplate mechanisms involving cyclo-trimerization of ready-made D-O-Leu-D-Ala-L-O-Val-L-Val via a thioesterase (TE) domain is proposed for cereulide biosynthesis, the exact mechanism is far from being understood. UPLC-TOF MS analysis of B. cereus strains in combination with 13C-labeling experiments now revealed tetra-, octa-, and dodecapeptides of a different sequence, namely (L-O-Val-L-Val-D-O-Leu-D-Ala)1-3, as intermediates of cereulide biosynthesis. Surprisingly, also di-, hexa-, and decadepsipeptides were identified which, together with the structures of the previously reported isocereulides E, F, and G, do not correlate to the currently proposed mechanism for cereulide biosynthesis and violate the canonical NRPS biosynthetic logic. UPLC-TOF MS metabolite analysis and bioinformatic gene cluster analysis highlighted dipeptides rather than single amino or hydroxy acids as the basic modules in tetradepsipeptide assembly and proposed the CesA C-terminal C* domain and the CesB C-terminal TE domain to function as a cooperative esterification and depsipeptide elongation center repeatedly recruiting the action of the C* domain to oligomerize tetradepsipeptides prior to the release of cereulide from the TE domain by macrocyclization.
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Affiliation(s)
- Sandra Marxen
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, Freising, 85354, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, Freising, 85354, Germany
| | - Andrea Rütschle
- Department of Microbiology, Central Institute for Food and Nutrition Research, Technische Universität München, Freising, 85350
| | - Genia Lücking
- Department of Microbiology, Central Institute for Food and Nutrition Research, Technische Universität München, Freising, 85350
| | - Elrike Frenzel
- Institute of Microbiology Department of Pathobiology, Functional Microbiology, University of Veterinary Medicine Vienna, Vienna, 1210, Austria
| | - Siegfried Scherer
- Department of Microbiology, Central Institute for Food and Nutrition Research, Technische Universität München, Freising, 85350.,Department of Biosciences, Chair of Microbial Ecology, WZW, Technische Universität München, Freising, 85350, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology Department of Pathobiology, Functional Microbiology, University of Veterinary Medicine Vienna, Vienna, 1210, Austria
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, Freising, 85354, Germany.,Bavarian Center for Biomolecular Mass Spectrometry, Technische Universität München, Gregor-Mendel Strasse 4, 85354, Freising, Germany
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Abstract
An aqueous ethanolic extract of the stem bark of Garcinia buchananii showed strong antioxidative activity using H2O2 scavenging, oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC) assays. Activity-guided fractionation afforded three new compounds, isomanniflavanone (1), an ent-eriodictyol-(3α→6)-dihydroquercetin-linked biflavanone, 1,5-dimethoxyajacareubin (2), and the depsidone garcinisidone-G (3), and six known compounds, (2″R,3″R)-preussianon, euxanthone, 2-isoprenyl-1,3,5,6-tetrahydroxyxanthone, jacareubin, isogarcinol, and garcinol. All compounds were described for the first time in Garcinia buchananii. The absolute configurations were determined by a combination of NMR, ECD spectroscopy, and polarimetry. These natural products showed high in vitro antioxidative power, especially isomanniflavanone, with an EC50 value of 8.5 μM (H2O2 scavenging), 3.50/4.95 mmol TE/mmol (H/L-TEAC), and 7.54/14.56 mmol TE/mmol (H/L-ORAC).
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München , Lise-Meitner-Straße 34, 85354 Freising, Germany
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Marxen S, Stark TD, Frenzel E, Rütschle A, Lücking G, Pürstinger G, Pohl EE, Scherer S, Ehling-Schulz M, Hofmann T. Chemodiversity of cereulide, the emetic toxin of Bacillus cereus. Anal Bioanal Chem 2015; 407:2439-53. [PMID: 25665710 DOI: 10.1007/s00216-015-8511-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/17/2015] [Accepted: 01/22/2015] [Indexed: 02/04/2023]
Abstract
Food-borne intoxications are increasingly caused by the dodecadepsipeptide cereulide, the emetic toxin produced by Bacillus cereus. As such intoxications pose a health risk to humans, a more detailed understanding on the chemodiversity of this toxin is mandatory for the reliable risk assessment of B. cereus toxins in foods. Mass spectrometric screening now shows a series of at least 18 cereulide variants, among which the previously unknown isocereulides A-G were determined for the first time by means of UPLC-TOF MS and ion-trap MS(n) sequencing, (13)C-labeling experiments, and post-hydrolytic dipeptide and enantioselective amino acid analysis. The data demonstrate a high microheterogeneity in cereulide and show evidence for a relaxed proof reading function of the non-ribosomal cereulide peptide synthetase complex giving rise to an enhanced cereulide chemodiversity. Most intriguingly, the isocereulides were found to differ widely in their cell toxicity correlating with their ionophoric properties (e.g., purified isocereulide A showed about 8-fold higher cytotoxicity than purified cereulide in the HEp-2 assay and induced an immediate breakdown of bilayer membranes). These findings provide a substantial contribution to the knowledge-based risk assessment of B. cereus toxins in foods, representing a still unsolved challenge in the field of food intoxications.
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Affiliation(s)
- Sandra Marxen
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, 85354, Freising, Germany
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Bader M, Stark TD, Dawid C, Lösch S, Hofmann T. All-trans-configuration in Zanthoxylum alkylamides swaps the tingling with a numbing sensation and diminishes salivation. J Agric Food Chem 2014; 62:2479-88. [PMID: 24606317 DOI: 10.1021/jf500399w] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The methanol soluble prepared from a supercritical fluid extract of Szechuan pepper (Zanthoxylum piperitum) was screened for its key tingling and numbing chemosensates by application of taste dilution analysis. Further separation of fractions perceived with the highest sensory impact, followed by LC-TOF-MS, LC-MS, and 1D/2D NMR experiments, led to the structure determination of the known alkylamides hydroxy-γ-sanshool (1), hydroxy-α-sanshool (2), hydroxy-β-sanshool (3), bungeanool (4), isobungeanool (5), and hydroxy-γ-isosanshool (6), as well as hydroxy-ε-sanshool (7), the structure of which has not yet been confirmed by NMR, and hydroxy-ζ-sanshool (8), which has not been previously reported in the literature. Psychophysical half-tongue experiments using filter paper rectangles (1 × 2 cm) as the vehicle revealed amides 1, 2, 4, 5, 7, and 8, showing at least one cis-configured double bond, elicited the well-known tingling and paresthetic orosensation above threshold levels of 3.5-8.3 nmol/cm(2). In contrast, the all-trans-configured amides 3 and 6 induced a numbing and anesthetic sensation above thresholds of 3.9 and 7.1 nmol/cm(2), respectively. Interestingly, the mono-cis-configured major amide 2 was found to induce massive salivation, whereas the all-trans-configuration of 3 did not.
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Affiliation(s)
- Matthias Bader
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
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Stark TD, Germann D, Balemba OB, Wakamatsu J, Hofmann T. New highly in vitro antioxidative 3,8″-linked Biflav(an)ones and Flavanone-C-glycosides from Garcinia buchananii stem bark. J Agric Food Chem 2013; 61:12572-12581. [PMID: 24295222 DOI: 10.1021/jf404783y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Very recently, we described highly antioxidative polyphenols isolated from the stem bark extract of the Garcinia buchananii tree. In this study, we describe additional antioxidants from Garcinia buchananii bark extract using hydrogen peroxide scavenging, oxygen radical absorbance capacity (ORAC), and trolox equivalent antioxidant capacity (TEAC) assays. UPLC-HR-ESI-TOF-MS(e) analysis, 1- and 2D-NMR, and circular dichroism (CD) spectroscopy led to the unequivocal identification of the antioxidative molecules as a series of five 3,8″-linked biflav(an)ones and two flavanone-C-glycosides. (2S,3R)-Taxifolin-6-C-β-d-glucopyranoside (2), (2R,3S,2″S,3″S)-manniflavanone (3), (2R,3S)-buchananiflavonol (4), and (2S,3R,2″R,3″R)-GB-1 (6) are new compounds, and (2S,3S)-taxifolin-6-C-β-d-glucopyranoside (1) was described so far only in one other plant. The structure of (2R,3S,2″R,3″R)-GB-1 (5) and (2R,3S,2″S)-GB2a (7) were confirmed. The H2O2 scavenging, TEAC, and the ORAC assays demonstrated that these natural products have an extraordinarily high antioxidative power, especially (2R,3S,2″S,3″S)-manniflavanone (3) with an EC50 value of 3.0 μM, 4.00 mmol TE/mmol, and 10.30 μmol TE/ μmol.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
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Abstract
Activity-guided fractionation was applied on an aged garlic extract (AGE), reported to show strong antioxidant activity, in order to locate the key in vitro antioxidant ingredients by means of the hydrogen peroxide scavenging (HPS) assay as well as the ORAC assay. Besides the previously reported four tetrahydro-β-carbolines, (1R,3S)- and (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid and (1R,3S)- and (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-1,3-dicarboxylic acid, LC-MS/MS, LC-TOF-MS, and 1D/2D-NMR experiments led to the identification of coniferyl alcohol and its dilignols (-)-(2R,3S)-dihydrodehydrodiconiferyl alcohol, (+)-(2S,3R)-dehydrodiconiferyl alcohol, erythro-guaiacylglycerol-β-O-4'-coniferyl ether, and threo-guaiacylglycerol-β-O-4'-coniferyl ether as the major antioxidants in AGE. The purified individual compounds showed high antioxidant activity, with EC50 values of 9.7-11.8 μM (HPS assay) and 2.60-3.65 μmol TE/μmol (ORAC assay), respectively.
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Affiliation(s)
- Toshiaki Matsutomo
- Technische Universität München , Lise-Meitner Strasse 34, D-85354 Freising, Germany
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Stark TD, Mtui DJ, Balemba OB. Ethnopharmacological Survey of Plants Used in the Traditional Treatment of Gastrointestinal Pain, Inflammation and Diarrhea in Africa: Future Perspectives for Integration into Modern Medicine. Animals (Basel) 2013; 3:158-227. [PMID: 26487315 PMCID: PMC4495512 DOI: 10.3390/ani3010158] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 11/19/2022] Open
Abstract
There is a growing need to find the most appropriate and effective treatment options for a variety of painful syndromes, including conditions affecting the gastrointestinal tract, for treating both veterinary and human patients. The most successful regimen may come through integrated therapies including combining current and novel western drugs with acupuncture and botanical therapies or their derivatives. There is an extensive history and use of plants in African traditional medicine. In this review, we have highlighted botanical remedies used for treatment of pain, diarrheas and inflammation in traditional veterinary and human health care in Africa. These preparations are promising sources of new compounds comprised of flavonoids, bioflavanones, xanthones, terpenoids, sterols and glycosides as well as compound formulas and supplements for future use in multimodal treatment approaches to chronic pain, gastrointestinal disorders and inflammation. The advancement of plant therapies and their derivative compounds will require the identification and validation of compounds having specific anti-nociceptive neuromodulatory and/or anti-inflammatory effects. In particular, there is need for the identification of the presence of compounds that affect purinergic, GABA, glutamate, TRP, opioid and cannabinoid receptors, serotonergic and chloride channel systems through bioactivity-guided, high-throughput screening and biotesting. This will create new frontiers for obtaining novel compounds and herbal supplements to relieve pain and gastrointestinal disorders, and suppress inflammation.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, Lise-Meitner Str. 34, D-85354, Freising, Germany.
| | - Dorah J Mtui
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
| | - Onesmo B Balemba
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
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Stark TD, Matsutomo T, Lösch S, Boakye PA, Balemba OB, Pasilis SP, Hofmann T. Isolation and structure elucidation of highly antioxidative 3,8″-linked biflavanones and flavanone-C-glycosides from Garcinia buchananii bark. J Agric Food Chem 2012; 60:2053-2062. [PMID: 22250972 DOI: 10.1021/jf205175b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of this study was to identify antioxidants from Garcinia buchananii bark extract using hydrogen peroxide scavenging and oxygen radical absorbance capacity (ORAC) assays. LC-MS/MS analysis, 1D- and 2D-NMR, and circular dichroism (CD) spectroscopy led to the unequivocal identification of the major antioxidative molecules as a series of three 3,8″-linked biflavanones and two flavanone-C-glycosides. Besides the previously reported (2R,3R,2″R,3″R)-naringenin-C-3/C-8″ dihydroquercetin linked biflavanone (GB-2; 4) and (2R,3S,2″R,3″R)-manniflavanone (3), whose stereochemistry has been revised, the antioxidants identified for the first time in Garcinia buchananii were (2R,3R)-taxifolin-6-C-β-D-glucopyranoside (1), (2R,3R)-aromadendrin-6-C-β-D-glucopyranoside (2), and the new compound (2R,3S,2″S)-buchananiflavanone (5). The H₂O₂ scavenging and the ORAC assays demonstrated that these natural products have an extraordinarily high antioxidative power, especially (2R,3S,2″R,3″R)-manniflavanone (3) and GB-2 (4), with EC₅₀ values of 2.8 and 2.2 μM, respectively, and 13.73 and 12.10 μmol TE/ μmol. These findings demonstrate that G. buchananii bark extract is a rich natural source of antioxidants.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, Lise-Meitner Str. 34, D-85354 Freising, Germany.
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