1
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Spreng S, Wannenmacher J, Gastl M, Dawid C, Hofmann T. Quantitative Antioxidant Profiling Throughout Beer Brewing Followed by Discovery and Isolation of Precursors from Barley ( Hordeum vulgare L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 38833300 DOI: 10.1021/acs.jafc.4c00998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The application of high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) revealed the origin and evolution of antioxidants during the brewing process of hopped and unhopped reference beer. As tachioside (3-methoxy-4-hydroxyphenyl-β-d-glucopyranoside), arbutin (4-hydroxyphenyl-β-d-glucopyranoside), and hordatines clearly increased during the fermentation step, the raw material barley was investigated as a source of the corresponding precursors. Therefore, 4-hydroxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, and 4-hydroxy-2-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside were isolated from barley for the first time, and identified using liquid chromatography-mass spectrometry (LC-MS) and one-dimensional/two-dimensional-nuclear magnetic resonance (1D/2D-NMR) experiments. Moreover, hordatine glucosides A, B, and C were isolated and identified from barley, and hordatine C glucoside was characterized for the first time. A fermentation model followed by HPLC-MS/MS analysis substantiated the release of tachioside from 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside by Saccharomyces cerevisiae. Quantitation experiments monitoring the content in wheat, barley, and different barley malt types demonstrated a wide range of concentrations, providing a basis for further comprehensive investigations to optimize the antioxidant yield in beer to contribute to improved flavor stability.
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Affiliation(s)
- Stefan Spreng
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, D-85354 Freising, Germany
| | - Julia Wannenmacher
- Chair of Brewing and Beverage Technology, Technical University of Munich, Weihenstephaner Steig 20, D-85354 Freising, Germany
| | - Martina Gastl
- Chair of Brewing and Beverage Technology, Technical University of Munich, Weihenstephaner Steig 20, D-85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, D-85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Gregor-Mendel-Straße 4, D-85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Str. 34, D-85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Gregor-Mendel-Straße 4, D-85354 Freising, Germany
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2
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Teng CE, Wang YM, Li TH, Chen SF. Quantification of Hop-Derived Bitter Compounds in Beer Using Liquid Chromatography Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:746-755. [PMID: 38422384 DOI: 10.1021/jasms.3c00439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Hops (Humulus lupulus L.) are essential raw materials for beer brewing, and the major contributors to beer bitterness are isohumulones (iso-α-acids) and humulinones. In recent years, many breweries have focused on the production of hop-forward beer styles by adding hops after or during the cold fermentation stage, which will tend to release humulinones or other hop-derived bitter compounds. In this study, a LC-MS/MS method was developed for quantification of 60 hop-derived bitter compounds in 25 min. Reverse-phase chromatography with an alkaline methanol/acetonitrile (70:30) mobile phase was used for the separation. The quantitative range was 0.053-3912 ng/mL with correlation coefficient r > 0.99, and the LOQ were 0.26 and 0.053 ng/mL for iso-α-acids and humulinones. Precision (RSD < 5.0%) and accuracy (recovery 86.3%-118.1%) were both satisfactory. The abundance of hop-derived bitter compounds in the dry-hopped beer (Double-India Pale Ale) and the nondry-hopped beer (Vienna Lager) were monitored throughout the fermentation and storage stages, and the formation of oxidation and cyclization products showed difference profiles between these two beers. The quantification results reveal how hop-derived bitter compounds change throughout the brewing process, as well as the influence of hops and brewing techniques on beer bitterness.
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Affiliation(s)
- Chieh-En Teng
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Yu-Meng Wang
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Tai-Huan Li
- Zhangmen Brewing Company, New Taipei City 22161, Taiwan
| | - Sung-Fang Chen
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
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3
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Tiroch J, Dunkel A, Sterneder S, Zehentner S, Behrens M, Di Pizio A, Ley JP, Lieder B, Somoza V. Human Gingival Fibroblasts as a Novel Cell Model Describing the Association between Bitter Taste Thresholds and Interleukin-6 Release. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:5314-5325. [PMID: 36943188 PMCID: PMC10080686 DOI: 10.1021/acs.jafc.2c06979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Human gingival fibroblast cells (HGF-1 cells) present an important cell model to investigate the gingiva's response to inflammatory stimuli such as lipopolysaccharides from Porphyromonas gingivalis (Pg-LPS). Recently, we demonstrated trans-resveratrol to repress the Pg-LPS evoked release of the pro-inflammatory cytokine interleukin-6 (IL-6) via involvement of bitter taste sensing receptor TAS2R50 in HGF-1 cells. Since HGF-1 cells express most of the known 25 TAS2Rs, we hypothesized an association between a compound's bitter taste threshold and its repressing effect on the Pg-LPS evoked IL-6 release by HGF-1 cells. To verify our hypothesis, 11 compounds were selected from the chemical bitter space and subjected to the HGF-1 cell assay, spanning a concentration range between 0.1 μM and 50 mM. In the first set of experiments, the specific role of TAS2R50 was excluded by results from structurally diverse TAS2R agonists and antagonists and by means of a molecular docking approach. In the second set of experiments, the HGF-1 cell response was used to establish a linear association between a compound's effective concentration to repress the Pg-LPS evoked IL-6 release by 25% and its bitter taste threshold concentration published in the literature. The Pearson correlation coefficient revealed for this linear association was R2 = 0.60 (p < 0.01), exceeding respective data for the test compounds from a well-established native cell model, the HGT-1 cells, with R2 = 0.153 (p = 0.263). In conclusion, we provide a predictive model for bitter tasting compounds with a potential to act as anti-inflammatory substances.
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Affiliation(s)
- Johanna Tiroch
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Andreas Dunkel
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Sonja Sterneder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Sofie Zehentner
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Maik Behrens
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Antonella Di Pizio
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | | | - Barbara Lieder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Veronika Somoza
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
- Chair
for Nutritional Systems Biology, Technical
University Munich, Freising 85354, Germany
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4
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Archeochemistry reveals the first steps into modern industrial brewing. Sci Rep 2022; 12:9251. [PMID: 35661112 PMCID: PMC9166709 DOI: 10.1038/s41598-022-12943-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/18/2022] [Indexed: 11/17/2022] Open
Abstract
A historical beer, dated to the German Empire era, was recently found in northern Germany. Its chemical composition represents a unique source of insights into brewing culture of the late nineteenth century when pioneer innovations laid the foundations for industrial brewing. Complementary analytics including metabolomics, microbiological, sensory, and beer attribute analysis revealed its molecular profile and certify the unprecedented good storage condition even after 130 years in the bottle. Comparing its chemical signature to that of four hundred modern brews allowed to describe molecular fingerprints teaching us about technological aspects of historical beer brewing. Several critical production steps such as malting and germ treatment, wort preparation and fermentation, filtration and storage, and compliance with the Bavarian Purity Law left detectable molecular imprints. In addition, the aging process of the drinkable brew could be analyzed on a chemical level and resulted in an unseen diversity of hops- and Maillard-derived compounds. Using this archeochemical forensic approach, the historical production process of a culturally significant beverage could be traced and the ravages of time made visible.
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5
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Sternberg U, Farès C. Statistical evaluation of simulated NMR data of flexible molecules. Phys Chem Chem Phys 2022; 24:9608-9618. [PMID: 35403649 DOI: 10.1039/d2cp00330a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new probability score-named χ-probability-is introduced for evaluating the fit of mixed NMR datasets to calculate molecular model ensembles, in order to answer challenging structural questions such as the determination of stereochemical configurations. Similar to the DP4 parameter, the χ-probability is based on Bayes theorem and expresses the probability that an experimental NMR dataset fits to a given individual within a finite set of candidate structures or configurations. Here, the χ-probability is applied to single out the correct configuration in four example cases, with increasing complexity and conformational mobility. The NMR data (which include RDCs, NOE distances and 3J couplings) are calculated from MDOC (Molecular Dynamics with Orientational Constraints) trajectories and are investigated against experimentally measured data. It is demonstrated that this approach singles out the correct stereochemical configuration with probabilities more than 98%, even for highly mobile molecules. In more demanding cases, a decisive χ-probability test requires that the datasets include high-quality NOE distances in addition to RDC values.
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Affiliation(s)
- Ulrich Sternberg
- Research Partner of Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. .,COSMOS-Software, Jena, Germany
| | - Christophe Farès
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm Platz 1, 45470 Mülheim an der Ruhr, Germany.
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6
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Wang YT, Yang ZX, Piao ZH, Xu XJ, Yu JH, Zhang YH. Prediction of flavor and retention index for compounds in beer depending on molecular structure using a machine learning method. RSC Adv 2021; 11:36942-36950. [PMID: 35494377 PMCID: PMC9044825 DOI: 10.1039/d1ra06551c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/30/2021] [Indexed: 11/28/2022] Open
Abstract
In order to make a preliminary prediction of flavor and retention index (RI) for compounds in beer, this work applied the machine learning method to modeling depending on molecular structure. Towards this goal, the flavor compounds in beer from existing literature were collected. The database was classified into four groups as aromatic, bitter, sulfury, and others. The RI values on a non-polar SE-30 column and a polar Carbowax 20M column from the National Institute of Standards Technology (NIST) were investigated. The structures were converted to molecular descriptors calculated by molecular operating environment (MOE), ChemoPy and Mordred, respectively. By combining the pretreatment of the descriptors, machine learning models, including support vector machine (SVM), random forest (RF) and k-nearest neighbour (kNN) were utilized for beer flavor models. Principal component regression (PCR), random forest regression (RFR) and partial least squares (PLS) regression were employed to predict the RI. The accuracy of the test set was obtained by SVM, RF, and kNN. Among them, the combination of descriptors calculated by Mordred and RF model afforded the highest accuracy of 0.686. R2 of the optimal regression model achieved 0.96. The results indicated that the models can be used to predict the flavor of a specific compound in beer and its RI value. In order to make a preliminary prediction of flavor and retention index (RI) for compounds in beer, this work applied the machine learning method to modeling depending on molecular structure.![]()
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Affiliation(s)
- Yu-Tang Wang
- Department of Food Science, Northeast Agricultural University Harbin 150030 PR China.,Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University China
| | - Zhao-Xia Yang
- State Key Laboratory of Biological Fermentation Engineering of Beer, Tsingtao Brewery Co., Ltd Qingdao 266061 Shandong China
| | - Zan-Hao Piao
- Department of Food Science, Northeast Agricultural University Harbin 150030 PR China.,Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University China
| | - Xiao-Juan Xu
- Department of Food Science, Northeast Agricultural University Harbin 150030 PR China.,Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University China
| | - Jun-Hong Yu
- State Key Laboratory of Biological Fermentation Engineering of Beer, Tsingtao Brewery Co., Ltd Qingdao 266061 Shandong China
| | - Ying-Hua Zhang
- Department of Food Science, Northeast Agricultural University Harbin 150030 PR China.,Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University China
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7
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Taniguchi Y, Kikuchi T, Sato S, Fujita M. Comprehensive Structural Analysis of the Bitter Components in Beer by the HPLC-Assisted Crystalline Sponge Method. Chemistry 2021; 28:e202103339. [PMID: 34755407 DOI: 10.1002/chem.202103339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Indexed: 11/10/2022]
Abstract
Trans-iso-α-acid is one of the main contributors to the bitter taste of fresh beer and is known to transform into various derivatives during beer aging. However, structural characterization of the derivatives has been a challenging task because of the formation of too many components. Herein, we report that most of the transformation products of trans-iso-α-acid, isolated in this study in only small quantities by HPLC, can be structurally analyzed with the crystalline sponge method. Thirteen compounds, including eight that were previously unreported, have been successfully isolated and analyzed with complete assignment of their absolute configuration. This provides an improved understanding of the chemical transformations that occur during beer aging.
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Affiliation(s)
- Yoshimasa Taniguchi
- Kirin Central Research Institute, Research & Development Division, Kirin Holdings Company, Ltd., 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Takashi Kikuchi
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo, 196-8666, Japan
| | - Sota Sato
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.,Integrated Molecular Structure Analysis Laboratory Social Cooperation Program, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Makoto Fujita
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.,Integrated Molecular Structure Analysis Laboratory Social Cooperation Program, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.,Division of Advanced Molecular Science, Institute for Molecular Science (IMS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi, 444-8787, Japan
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8
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Berton JKET, Verbeke Y, Van Durme B, Huvaere K. Radical Intermediates in the Degradation of Hop Acids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9642-9653. [PMID: 34382782 DOI: 10.1021/acs.jafc.1c02977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Radical formation in isohumulones was investigated under different types of stress, including temperature, transition metal ions, and hydrogen peroxide. Including dihydroisohumulones and tetrahydroisohumulones, as relevant analogues, allowed us to evaluate critical functionalities in radical formation. Using spin-trapping methodology with 5,5-dimethyl-1-pyrroline N-oxide and N-tert-butyl-α-phenylnitrone as relevant traps, followed by simulation of corresponding spin adducts, identification of incipient radicals was attempted. The isohexenoyl side chain in isohumulones, but not present in dihydro- and tetrahydroisohumulones, was most sensitive to radical formation. Kinetic profiles further demonstrated that radical formation in this moiety was accelerated in the presence of ferrous ions. Reactivity of parent six-membered-ring humulones in radical formation was different, as scavenging of free radical species was more important. Lupulones, despite similarity with humulones, showed a different behavior with an obvious radical decay pathway during ageing, mainly ascribed to radical formation on the ring structure. Quantification of final spin adducts allowed us to determine absolute importance of the different degradation pathways. Eventually, mechanisms are presented explaining why isohumulones are more prone to radical processes in (aut)oxidation and thermal decay than close relatives such as dihydroisohumulones.
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Affiliation(s)
| | - Yannis Verbeke
- EcoSynth NV, Industrielaan 12, 9800 Deinze, Belgium
- Department of Chemistry, Trainee Affiliated to the Odisee University of Applied Sciences Associated to the Catholic University of Leuven, Gebroeders de Smetstraat 1, 9000 Ghent, Belgium
| | - Bo Van Durme
- EcoSynth NV, Industrielaan 12, 9800 Deinze, Belgium
- Faculty of Sciences, Department of Chemistry, Trainee Affiliated to Ghent University, Krijgslaan 281, 9000 Ghent, Belgium
| | - Kevin Huvaere
- EcoSynth NV, Industrielaan 12, 9800 Deinze, Belgium
- Plinius Labs NV, Venecolaan 50G, 9880 Aalter, Belgium
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9
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Kishimoto T, Teramoto S, Fujita A, Yamada O. Evaluation of Components Contributing to the International Bitterness Unit of Wort and Beer. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2021. [DOI: 10.1080/03610470.2021.1878684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Toru Kishimoto
- National Research Institute of Brewing, Hiroshima, Japan
| | | | - Akiko Fujita
- National Research Institute of Brewing, Hiroshima, Japan
| | - Osamu Yamada
- National Research Institute of Brewing, Hiroshima, Japan
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10
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Recent patents on therapeutic activities of xanthohumol: a prenylated chalconoid from hops ( Humulus lupulus L.). Pharm Pat Anal 2021; 10:37-49. [PMID: 33445965 DOI: 10.4155/ppa-2020-0026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
There is expanding proof that specific natural compounds found in plants have additional conventional medicinal properties. One such compound is xanthohumol (XN), which is being explored as an antimicrobial, anticarcinogenic, antidiabetic and anti-inflammatory agent - aside from its utilization in dealing with conditions like autism, bone and skin improvement and microbial infections, lipid-related illnesses, and so on. XN is reported to suppress the uncontrolled production of inflammatory mediators responsible for diseases including cardiovascular disease, neurodegeneration and tumors. Further, it is accounted to limit adipogenesis and control obesity by focusing on principal adipocyte marker proteins. It is most generally utilized in the brewing industry as an additive and flavoring agent to add bitterness and aroma to beer. Present investigation sum up the patents filed in most recent 2 years on development of different pharmaceutical mixes and strategies dependent on various therapeutic potentials of XN.
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11
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Sternberg U, Tzvetkova P, Muhle-Goll C. The simulation of NMR data of flexible molecules: sagittamide A as an example for MD simulations with orientational constraints. Phys Chem Chem Phys 2020; 22:17375-17384. [PMID: 32705098 DOI: 10.1039/d0cp01905d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The recently developed MDOC (Molecular Dynamics with Orientational Constraints) simulation is applied for the first time to a fully flexible molecule. MDOC simulations aim to single out the naturally existing configuration of molecules and to elucidate conformer populations. The performance of the method was first demonstrated on a well-studied test case, the five-membered ring lactone (α-methylene-γ-butyrolactone). In the case of sagittamide A, one-bond 1H-13C residual dipolar couplings (RDC) are used as orientational constraints that reorient the molecule or parts of it. In addition, NOE distances and 3J scalar couplings are used as constraints. Five possible configurations of sagittamide A (labelled a to e) are considered. One experimental RDC value per flexible unit was available and this was not sufficient to single out one valid configuration. The problem could be solved by including NOE distances as well as 3J couplings as complementary constraints into the MDOC simulations. In accordance with former investigations, we confirmed the configuration a for the natural product. A detailed analysis of conformers of the central chain of 6 chiral carbon atoms could be given by inspecting the MDOC trajectory. The relative abundance of these conformers is crucial in fulfilling all three sets of constraints.
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Affiliation(s)
- Ulrich Sternberg
- Research Partner of Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. and COSMOS-Software, Jena, Germany
| | - Pavleta Tzvetkova
- Institute of Biological Interfaces 4, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Claudia Muhle-Goll
- Institute of Biological Interfaces 4, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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12
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Hao J, Speers R, Fan H, Deng Y, Dai Z. A Review of Cyclic and Oxidative Bitter Derivatives of Alpha, Iso-Alpha and Beta-Hop Acids. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2020. [DOI: 10.1080/03610470.2020.1712641] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Junguang Hao
- Key Laboratory of Characteristic Fruits and Vegetables Fermentation, College of Food Science and Engineering, Beibu Gulf University, Qinzhou, Guangxi, P.R. China
| | - R.A. Speers
- Canadian Institute of Fermentation Technology, Dalhousie University, Halifax, Nova Scotia Canada
- International Centre of Brewing and Distilling, Heriot Watt University, Riccarton, Edinburgh, Scotland
- Department of Brewing Science, Qilu University, Jinan, Shandong, P.R. China
| | - Heliang Fan
- Key Laboratory of Characteristic Fruits and Vegetables Fermentation, College of Food Science and Engineering, Beibu Gulf University, Qinzhou, Guangxi, P.R. China
| | - Yang Deng
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong, P.R. China
| | - Ziru Dai
- Key Laboratory of Characteristic Fruits and Vegetables Fermentation, College of Food Science and Engineering, Beibu Gulf University, Qinzhou, Guangxi, P.R. China
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13
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Conformational Investigations in Flexible Molecules Using Orientational NMR Constraints in Combination with 3J-Couplings and NOE Distances. Molecules 2019; 24:molecules24234417. [PMID: 31816930 PMCID: PMC6930577 DOI: 10.3390/molecules24234417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 12/19/2022] Open
Abstract
The downscaling of NMR tensorial interactions, such as dipolar couplings, from tens of kilohertz to a few hertz in low-order media is the result of dynamics spanning several orders of magnitudes, including vibrational modes (~ns-fs), whole-molecule reorientation (~ns) and higher barrier internal conformational exchange (<ms). In this work, we propose to employ these dynamically averaged interactions to drive an “alignment-tensor-free” molecular dynamic simulation with orientation constraints (MDOC) in order to efficiently access the conformational space sampled by flexible small molecules such as natural products. Key to this approach is the application of tensorial pseudo-force restraints which simultaneously guide the overall reorientation and conformational fluctuations based on defined memory function over the running trajectory. With the molecular mechanics force-field, which includes bond polarization theory (BPT), and complemented with other available NMR parameters such as NOEs and scalar J-couplings, MDOC efficiently arrives at dynamic ensembles that reproduce the entire NMR dataset with exquisite accuracy and theoretically reveal the systems conformational space and equilibrium. The method as well as its potential towards configurational elucidation is presented on diastereomeric pairs of flexible molecules: a small 1,4-diketone 1 with a single rotatable bond as well as a 24-ring macrolide related to the natural product mandelalide A 2.
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14
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Tzvetkova P, Sternberg U, Gloge T, Navarro-Vázquez A, Luy B. Configuration determination by residual dipolar couplings: accessing the full conformational space by molecular dynamics with tensorial constraints. Chem Sci 2019; 10:8774-8791. [PMID: 31803450 PMCID: PMC6849632 DOI: 10.1039/c9sc01084j] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/19/2019] [Indexed: 12/27/2022] Open
Abstract
Residual dipolar couplings (RDCs) and other residual anisotropic NMR parameters provide valuable structural information of high quality and quantity, bringing detailed structural models of flexible molecules in solution in reach. The corresponding data interpretation so far is directly or indirectly based on the concept of a molecular alignment tensor, which, however, is ill-defined for flexible molecules. The concept is typically applied to a single or a small set of lowest energy structures, ignoring the effect of vibrational averaging. Here, we introduce an entirely different approach based on time averaged molecular dynamics with dipolar couplings as tensorial orientational restraints that can be used to solve structural problems in molecules of any size without the need of introducing an explicit molecular alignment tensor into the computation. RDC restraints are represented by their full 3D interaction tensor in the laboratory frame, for which pseudo forces are calculated using a secular dipolar Hamiltonian as the target. The resulting rotational averaging of each individual tensorial restraint leads to structural ensembles that best fulfil the experimental data. Using one-bond RDCs, the approach has been implemented in the force field procedures of the program COSMOS and extensively tested. A concise theoretical introduction, including the special treatment of force fields for stable and fast MD simulations, as well as applications regarding configurational analyses of small to medium-sized organic molecules with different degrees of flexibility, is given. The observed results are discussed in detail.
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Affiliation(s)
- Pavleta Tzvetkova
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6 , 76131 Karlsruhe , Germany . ;
| | - Ulrich Sternberg
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6 , 76131 Karlsruhe , Germany . ;
| | - Thomas Gloge
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6 , 76131 Karlsruhe , Germany . ;
| | - Armando Navarro-Vázquez
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6 , 76131 Karlsruhe , Germany . ;
| | - Burkhard Luy
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6 , 76131 Karlsruhe , Germany . ;
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15
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Baert JJ, De Clippeleer J, Bustillo Trueba P, Jaskula-Goiris B, De Rouck G, Aerts G, De Cooman L. Exploring Aldehyde Release in Beer by 4-Vinylpyridine and the Effect of Cysteine Addition on the Beer’s Pool of Bound Aldehydes. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1080/03610470.2018.1518639] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Jeroen J. Baert
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
| | - Jessika De Clippeleer
- Faculty of Bioscience Engineering, Department of Biotechnology, Laboratory for Brewing Science & Technology, Ghent University, Ghent, Belgium
- Faculty of Science and Technology, Department of Biosciences and Food Sciences, Laboratory for Brewing Science & Technology, University College Ghent, Ghent, Belgium
| | - Paula Bustillo Trueba
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
| | - Barbara Jaskula-Goiris
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
| | - Gert De Rouck
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
| | - Guido Aerts
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
| | - Luc De Cooman
- Department of Microbial and Molecular Systems (MS), Cluster for Bioengineering Technology (CBeT), Laboratory of Enzyme, Fermentation and Brewing Technology (EFBT), Technology Campus Ghent, KU Leuven, Ghent, Belgium
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16
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Silva Ferreira C, Thibault de Chanvalon E, Bodart E, Collin S. Why Humulinones are Key Bitter Constituents Only After Dry Hopping: Comparison With Other Belgian Styles. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1080/03610470.2018.1503925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Carlos Silva Ferreira
- Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté des Bioingénieurs, Université catholique de Louvain, Louvain-la-Neuve, B-1348, Belgium
| | - Eloi Thibault de Chanvalon
- Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté des Bioingénieurs, Université catholique de Louvain, Louvain-la-Neuve, B-1348, Belgium
| | - Etienne Bodart
- Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté des Bioingénieurs, Université catholique de Louvain, Louvain-la-Neuve, B-1348, Belgium
| | - Sonia Collin
- Unité de Brasserie et des Industries Alimentaires, Earth and Life Institute ELIM, Faculté des Bioingénieurs, Université catholique de Louvain, Louvain-la-Neuve, B-1348, Belgium
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17
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Jaskula-Goiris B, De Causmaecker B, De Rouck G, Aerts G, Paternoster A, Braet J, De Cooman L. Influence of transport and storage conditions on beer quality and flavour stability. JOURNAL OF THE INSTITUTE OF BREWING 2018. [DOI: 10.1002/jib.535] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- B. Jaskula-Goiris
- Faculty of Engineering Technology, Department of Microbial and Molecular Systems, Cluster for Bioengineering Technology, Laboratory of Enzyme, Fermentation and Brewing Technology, Technology Campus Ghent; KU Leuven; Gebroeders De Smetstraat 1 9000 Ghent Belgium
| | - B. De Causmaecker
- Faculty of Engineering Technology, Department of Microbial and Molecular Systems, Cluster for Bioengineering Technology, Laboratory of Enzyme, Fermentation and Brewing Technology, Technology Campus Ghent; KU Leuven; Gebroeders De Smetstraat 1 9000 Ghent Belgium
| | - G. De Rouck
- Faculty of Engineering Technology, Department of Microbial and Molecular Systems, Cluster for Bioengineering Technology, Laboratory of Enzyme, Fermentation and Brewing Technology, Technology Campus Ghent; KU Leuven; Gebroeders De Smetstraat 1 9000 Ghent Belgium
| | - G. Aerts
- Faculty of Engineering Technology, Department of Microbial and Molecular Systems, Cluster for Bioengineering Technology, Laboratory of Enzyme, Fermentation and Brewing Technology, Technology Campus Ghent; KU Leuven; Gebroeders De Smetstraat 1 9000 Ghent Belgium
| | - A. Paternoster
- Faculty of Applied Economic Sciences, Department of Engineering Management; University of Antwerp; Prinsstraat 13 2000 Antwerp Belgium
| | - J. Braet
- Faculty of Applied Economic Sciences, Department of Engineering Management; University of Antwerp; Prinsstraat 13 2000 Antwerp Belgium
| | - L. De Cooman
- Faculty of Engineering Technology, Department of Microbial and Molecular Systems, Cluster for Bioengineering Technology, Laboratory of Enzyme, Fermentation and Brewing Technology, Technology Campus Ghent; KU Leuven; Gebroeders De Smetstraat 1 9000 Ghent Belgium
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18
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Li GW, Liu H, Qiu F, Wang XJ, Lei XX. Residual Dipolar Couplings in Structure Determination of Natural Products. NATURAL PRODUCTS AND BIOPROSPECTING 2018; 8:279-295. [PMID: 29943349 PMCID: PMC6102172 DOI: 10.1007/s13659-018-0174-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 06/14/2018] [Indexed: 05/16/2023]
Abstract
The determination of natural products stereochemistry remains a formidable task. Residual dipolar couplings (RDCs) induced by anisotropic media are a powerful tool for determination of the stereochemistry of organic molecule in solution. This review will provide a short introduction on RDCs-based methodology for the structural elucidation of natural products. Special attention is given to the current availability of alignment media in organic solvents. The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized. This review provides a short introduction on RDCs-based methodology for the structural elucidation of natural products. Special attention is given to the current availability of alignment media in organic solvents. The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.
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Affiliation(s)
- Gao-Wei Li
- College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu, 476000, People's Republic of China
| | - Han Liu
- School of Pharmaceutical Sciences, South Central University for Nationalities, Wuhan, 430074, People's Republic of China
| | - Feng Qiu
- School of Pharmaceutical Sciences, South Central University for Nationalities, Wuhan, 430074, People's Republic of China
| | - Xiao-Juan Wang
- College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu, 476000, People's Republic of China
| | - Xin-Xiang Lei
- School of Pharmaceutical Sciences, South Central University for Nationalities, Wuhan, 430074, People's Republic of China.
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19
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Schmidt C, Biendl M, Lagemann A, Stettner G, Vogt C, Dunkel A, Hofmann T. Influence of Different Hop Products on the cis/trans Ratio of Iso-α-Acids in Beer and Changes in Key Aroma and Bitter Taste Molecules during Beer Ageing. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2014-0326-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Martin Biendl
- Hopsteiner, Auhofstrasse 16, 84048 Mainburg, Germany
| | - Annika Lagemann
- Bitburger Braugruppe GmbH, Römermauer 3, 54634 Bitburg, Germany
| | - Georg Stettner
- Bitburger Braugruppe GmbH, Römermauer 3, 54634 Bitburg, Germany
| | - Christian Vogt
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Andreas Dunkel
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, 85354 Freising, Germany
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20
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Spreng S, Hofmann T. Activity-Guided Identification of in Vitro Antioxidants in Beer. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:720-731. [PMID: 29287473 DOI: 10.1021/acs.jafc.7b05674] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In order to locate the key antioxidants contributing to oxidative stability of beer, activity-guided fractionation in combination with the oxygen radical absorbance capacity (ORAC) assay, hydrogen peroxide scavenging (HPS) assay, and linoleic acid (LA) assay was applied to a pilsner-type beer. LC-MS and 1D/2D NMR experiments led to the identification of a total of 31 antioxidants, among which 3-methoxy-4-hydroxyphenyl-β-d-glucopyranoside (tachioside), 4-(2-formylpyrrol-1-yl)butyric acid, 4-[2-formyl-5-(hydroxymethyl)pyrrol-1-yl]butyric acid, n-multifidol-3-O-β-d-glucoside, quercetin-3-O-(6″-malonyl)-glucoside, 4-feruloylquinic acid, syringaresinol, saponarin, and hordatines A-C have been isolated from beer for the first time. On a molar comparison, the hordatines A-C, saponarin, and quercetin-3-O-β-d-(6″-malonyl)glucoside were evaluated with the highest antioxidant activities of all identified beer constituents, reaching values of 10-17.5 (ORAC), 2.0-4.1 (HPS), and 1.1-6.1 μmol TE/μmol (LA) for hordatines A-C.
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Affiliation(s)
- Stefan Spreng
- Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München , Lise-Meitner-Strasse 34, D-85354 Freising, Germany , and
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München , Lise-Meitner-Strasse 34, D-85354 Freising, Germany , and
- Bavarian Center for Biomolecular Mass Spectrometry, Gregor-Mendel-Straße 4, D-85354 Freising, Germany
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21
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Koos MRM, Feyrer H, Luy B. Broadband RF-amplitude-dependent flip angle pulses with linear phase slope. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:797-803. [PMID: 28321918 DOI: 10.1002/mrc.4593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 06/06/2023]
Abstract
Pulse sequences in NMR spectroscopy sometimes require the application of pulses with effective flip angles different from 90° and 180°. Previously (Magn. Reson. Chem. 2015, 53, 886-893), offset-compensated broadband excitation pulses with RF-amplitude-dependent effective flip angles (RADFA) were introduced that are applicable in such cases. However, especially RF-amplitude-restricted RADFA pulses turned out to perform not as good as desired in terms of achievable bandwidths. Here, a class of RF-amplitude-restricted RADFA pulses with linear phase slope is introduced that allows excitation over much larger bandwidths with better performance. In this theoretical work, the basic principle of the pulse class is explained, their physical limits explored, and their properties, also compared with other pulse classes, discussed in detail. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Martin R M Koos
- Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021, Karlsruhe, Germany
| | - Hannes Feyrer
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Scheeles Väg 2, 171 77, Stockholm, Sweden
| | - Burkhard Luy
- Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021, Karlsruhe, Germany
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
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22
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Schulze-Sünninghausen D, Becker J, Koos MRM, Luy B. Improvements, extensions, and practical aspects of rapid ASAP-HSQC and ALSOFAST-HSQC pulse sequences for studying small molecules at natural abundance. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 281:151-161. [PMID: 28603039 DOI: 10.1016/j.jmr.2017.05.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/17/2017] [Accepted: 05/22/2017] [Indexed: 06/07/2023]
Abstract
Previously we introduced two novel NMR experiments for small molecules, the so-called ASAP-HSQC and ALSOFAST-HSQC (Schulze-Sünninghausen et al., 2014), which allow the detection of heteronuclear one-bond correlations in less than 30s at natural abundance. We propose an improved symmetrized pulse scheme of the basic experiment to minimize artifact intensities and the combination with non-uniform sampling to enable the acquisition of conventional HSQC spectra in as short as a couple of seconds and extremely 13C-resolved spectra in less than ten minutes. Based on steady state investigations, a first estimate to relative achievable signal intensities with respect to conventional, ASAP-, and ALSOFAST-HSQC experiments is given. In addition, we describe several extensions to the basic pulse schemes, like a multiplicity-edited version, a revised symmetrized CLIP-ASAP-HSQC, an ASAP-/ALSOFAST-HSQC sequence with broadband BIRD-based 1H,1H decoupling, and a symmetrized sequence optimized for water suppression. Finally, RF-power considerations with respect to the high duty cycle of the experiments are given.
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Affiliation(s)
- David Schulze-Sünninghausen
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany; Bruker BioSpin GmbH, Rudolf-Plank-Str. 23, 76275 Ettlingen, Germany
| | - Johanna Becker
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Martin R M Koos
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Burkhard Luy
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
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23
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Reller M, Wesp S, Koos MRM, Reggelin M, Luy B. Biphasic Liquid Crystal and the Simultaneous Measurement of Isotropic and Anisotropic Parameters by Spatially Resolved NMR Spectroscopy. Chemistry 2017. [DOI: 10.1002/chem.201702126] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Malin Reller
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4 - Magnetische Resonanz; Karlsruher Institut für Technologie (KIT); Fritz-Haber-Weg 6 76131 Karlsruhe Germany
| | - Svenja Wesp
- Organische Chemie; Technische Universität Darmstadt; Alarich-Weiss Str. 4 64287 Darmstadt Germany
| | - Martin R. M. Koos
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4 - Magnetische Resonanz; Karlsruher Institut für Technologie (KIT); Fritz-Haber-Weg 6 76131 Karlsruhe Germany
| | - Michael Reggelin
- Organische Chemie; Technische Universität Darmstadt; Alarich-Weiss Str. 4 64287 Darmstadt Germany
| | - Burkhard Luy
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4 - Magnetische Resonanz; Karlsruher Institut für Technologie (KIT); Fritz-Haber-Weg 6 76131 Karlsruhe Germany
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24
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Gürdeniz G, Jensen MG, Meier S, Bech L, Lund E, Dragsted LO. Detecting Beer Intake by Unique Metabolite Patterns. J Proteome Res 2016; 15:4544-4556. [DOI: 10.1021/acs.jproteome.6b00635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gözde Gürdeniz
- Department
of Nutrition, Sports and Exercise, Faculty of Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg
C, 1958, Denmark
| | - Morten Georg Jensen
- Carlsberg Research Laboratory A/S, Gamle Carlsberg Vej 6-10, 1799 Copenhagen V, Denmark
| | - Sebastian Meier
- Department
of Chemistry, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Lene Bech
- Carlsberg Research Laboratory A/S, Gamle Carlsberg Vej 6-10, 1799 Copenhagen V, Denmark
| | - Erik Lund
- Carlsberg Research Laboratory A/S, Gamle Carlsberg Vej 6-10, 1799 Copenhagen V, Denmark
| | - Lars Ove Dragsted
- Department
of Nutrition, Sports and Exercise, Faculty of Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg
C, 1958, Denmark
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25
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Tzvetkova P, Luy B. Q.E.COSY: determining sign and size of small deuterium residual quadrupolar couplings using an extended E.COSY principle. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:351-357. [PMID: 26763050 DOI: 10.1002/mrc.4386] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/30/2015] [Accepted: 10/23/2015] [Indexed: 06/05/2023]
Abstract
Residual quadrupolar couplings contain important structural information comparable with residual dipolar couplings. However, the measurement of sign and size of especially small residual quadrupolar couplings is difficult. Here, we present an extension of the E.COSY principle to spin systems consisting of a Spin 1 coupled to a spin ½ nucleus, which allows the determination of the sign of the quadrupolar coupling of the Spin 1 nucleus relative to the heteronuclear coupling between the spins. The so-called Q.E.COSY approach is demonstrated with its sign-sensitivity using variable angle NMR, stretched gels and liquid crystalline phases applied to various CD and CD3 groups. Especially the sign-sensitive measurement of residual quadrupolar couplings that remain unresolved in conventional deuterium 1D spectra is shown.
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Affiliation(s)
- Pavleta Tzvetkova
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Burkhard Luy
- Institute of Organic Chemistry and Institute for Biological Interfaces 4 - Magnetic Resonance, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
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26
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Dresel M, Vogt C, Dunkel A, Hofmann T. The Bitter Chemodiversity of Hops (Humulus lupulus L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:7789-7799. [PMID: 27696843 DOI: 10.1021/acs.jafc.6b03933] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To map the chemodiversity of key bitter compounds in hops, a total of 75 different samples collected from the global hop market were analyzed for 117 key bitter tastants by means of a multiparametric HPLC-MS/MSMRM method. Among the compounds detected, 2'',3''-epoxyxanthohumol was detected for the first time in hops and iso¬xantho¬humol M was identified as a marker compound for varieties grown in Germany. Hop ageing experiments in the absence and presence of air oxygen, respectively, were conducted to address the stability of hop-derived compounds during long-term storage.
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27
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Taniguchi Y, Yamada M, Taniguchi H, Matsukura Y, Shindo K. Chemical Characterization of Beer Aging Products Derived from Hard Resin Components in Hops (Humulus lupulus L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:10181-10191. [PMID: 26507444 DOI: 10.1021/acs.jafc.5b04138] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The bitter taste of beer originates from resins in hops (Humulus lupulus L.), which are classified into two subtypes (soft and hard). Whereas the nature and reactivity of soft-resin-derived compounds, such as α-, β-, and iso-α-acids, are well studied, there is only a little information on the compounds in hard resin. For this work, hard resin was prepared from stored hops and investigated for its compositional changes in an experimental model of beer aging. The hard resin contained a series of α-acid oxides. Among them, 4'-hydroxyallohumulinones were unstable under beer storage conditions, and their transformation induced primary compositional changes of the hard resin during beer aging. The chemical structures of the products, including novel polycyclic compounds scorpiohumulinols A and B and dicyclohumulinols A and B, were determined by HRMS and NMR analyses. These compounds were proposed to be produced via proton-catalyzed cyclization reactions of 4'-hydroxyallohumulinones. Furthermore, they were more stable than their precursor 4'-hydroxyallohumulinones during prolonged storage periods.
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Affiliation(s)
- Yoshimasa Taniguchi
- Central Laboratories for Key Technologies, Research & Development Division, KIRIN Company, Ltd. , 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa 236-0004, Japan
| | - Makiko Yamada
- Central Laboratories for Key Technologies, Research & Development Division, KIRIN Company, Ltd. , 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa 236-0004, Japan
| | - Harumi Taniguchi
- Central Laboratories for Key Technologies, Research & Development Division, KIRIN Company, Ltd. , 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa 236-0004, Japan
| | - Yasuko Matsukura
- Central Laboratories for Key Technologies, Research & Development Division, KIRIN Company, Ltd. , 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa 236-0004, Japan
| | - Kazutoshi Shindo
- Department of Food and Nutrition, Japan Women's University , 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
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28
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Becker J, Luy B. CLIP-ASAP-HSQC for fast and accurate extraction of one-bond couplings from isotropic and partially aligned molecules. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:878-885. [PMID: 26137959 DOI: 10.1002/mrc.4276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/07/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
Fast measurement of heteronuclear one-bond couplings, a class of NMR parameters valuable for structure elucidation, is highly desirable, especially if samples undergo chemical reactions or dynamic processes are observed. Methods presented so far face severe limitations in terms of resolution, accessible bandwidth, and sensitivity. We present the CLean InPhase-Acceleration by Sharing Adjacent Polarization-HSQC (CLIP-ASAP-HSQC) pulse sequence that allows fast acquisition of spectra with clean inphase multiplets in about 25 s. The performance in terms of accurate extraction of one-bond couplings is demonstrated on three test samples including partially aligned molecules.
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Affiliation(s)
- Johanna Becker
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces 4 - Magnetic Resonance, Eggenstein-Leopoldshafen, Germany
| | - Burkhard Luy
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces 4 - Magnetic Resonance, Eggenstein-Leopoldshafen, Germany
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Karlsruhe, Germany
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29
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Koos MRM, Feyrer H, Luy B. Broadband excitation pulses with variable RF amplitude-dependent flip angle (RADFA). MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:886-893. [PMID: 26259565 DOI: 10.1002/mrc.4297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/02/2015] [Accepted: 06/18/2015] [Indexed: 06/04/2023]
Abstract
Pulse sequences in NMR spectroscopy sometimes require the adjustment of effective flip angles with respect to experiment-specific or sample-specific parameters. Here, we present a quality factor for efficient optimization of offset-compensated broadband excitation pulses with RF amplitude-dependent effective flip angles (RADFA). After proof of principle, physical limits of RF amplitude-restricted and RF power-restricted broadband RADFA pulses are explored and corresponding pulse shapes and performances characterized in detail.
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Affiliation(s)
- Martin R M Koos
- Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021 Karlsruhe, Germany
| | - Hannes Feyrer
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Burkhard Luy
- Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021 Karlsruhe, Germany
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30
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Taniguchi Y, Matsukura Y, Taniguchi H, Koizumi H, Katayama M. Development of preparative and analytical methods of the hop bitter acid oxide fraction and chemical properties of its components. Biosci Biotechnol Biochem 2015; 79:1684-94. [PMID: 25996959 DOI: 10.1080/09168451.2015.1042832] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS(2) revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides.
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Affiliation(s)
- Yoshimasa Taniguchi
- a Central Laboratories for Key Technologies, Research & Development Division , KIRIN Company, Ltd. , Kanagawa , Japan
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31
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Dresel M, Dunkel A, Hofmann T. Sensomics analysis of key bitter compounds in the hard resin of hops (Humulus lupulus L.) and their contribution to the bitter profile of Pilsner-type beer. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:3402-3418. [PMID: 25793563 DOI: 10.1021/acs.jafc.5b00239] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent brewing trials indicated the occurrence of valuable bitter compounds in the hard resin fraction of hop. Aiming at the discovery of these compounds, hop's ε-resin was separated by means of a sensory guided fractionation approach and the key taste molecules were identified by means of UV/vis, LC-TOF-MS, and 1D/2D-NMR studies as well as synthetic experiments. Besides a series of literature known xanthohumol derivatives, multifidol glucosides, flavon-3-on glycosides, and p-coumaric acid esters, a total of 11 bitter tastants are reported for the first time, namely, 1",2"-dihydroxanthohumol F, 4'-hydroxytunicatachalcone, isoxantholupon, 1-methoxy-4-prenylphloroglucinol, dihydrocyclohumulohydrochinone, xanthohumols M, N, and P, and isoxanthohumols M, N, and P, respectively. Human sensory analysis revealed low bitter recognition threshold concentrations ranging from 5 (co-multifidol glucopyranoside) to 198 μmol/L (trans-p-coumaric acid ethyl ester) depending on their chemical structure. For the first time, LC-MS/MS quantitation of these taste compounds in Pilsner-type beer, followed by taste re-engineering experiments, revealed the additive contribution of iso-α-acids and the identified hard resin components to be truly necessary and sufficient for constructing the authentic bitter percept of beer. Finally, brewing trails using the ε-resin as the only hop source impressively demonstrated the possibility to produce beverages strongly enriched with prenylated hop flavonoids.
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Affiliation(s)
- Michael Dresel
- †Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, D-84354 Freising, Germany
| | - Andreas Dunkel
- †Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, D-84354 Freising, Germany
| | - Thomas Hofmann
- †Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München, Lise-Meitner-Straße 34, D-84354 Freising, Germany
- ‡Bavarian Center for Biomolecular Mass Spectrometry, Gregor-Mendel-Straße 4, 85354 Freising, Germany
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Londesborough J, Dresel M, Gibson B, Juvonen R, Holopainen U, Mikkelson A, Seppänen-Laakso T, Viljanen K, Virtanen H, Wilpola A, Hofmann T, Wilhelmson A. Analysis of beers from an 1840s' shipwreck. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:2525-2536. [PMID: 25664918 DOI: 10.1021/jf5052943] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two bottles of beer from an about 170-year-old shipwreck (M1 Fö 403.3) near the Åland Islands in the Baltic Sea were analyzed. Hop components and their degradation compounds showed that the bottles contained two different beers, one more strongly hopped than the other. The hops used contained higher levels of β-acids than modern varieties and were added before the worts were boiled, converting α-acids to iso-α-acids and β-acids to hulupones. High levels of organic acids, carbonyl compounds, and glucose indicated extensive bacterial and enzyme activity during aging. However, concentrations of yeast-derived flavor compounds were similar to those of modern beers, except that 3-methylbutyl acetate was unusually low in both beers and 2-phenylethanol and possibly 2-phenylethyl acetate were unusually high in one beer. Concentrations of phenolic compounds were similar to those in modern lagers and ales.
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Affiliation(s)
- John Londesborough
- VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Finland
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Steenackers B, De Cooman L, De Vos D. Chemical transformations of characteristic hop secondary metabolites in relation to beer properties and the brewing process: a review. Food Chem 2014; 172:742-56. [PMID: 25442616 DOI: 10.1016/j.foodchem.2014.09.139] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/20/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
Abstract
The annual production of hops (Humulus lupulus L.) exceeds 100,000 mt and is almost exclusively consumed by the brewing industry. The value of hops is attributed to their characteristic secondary metabolites; these metabolites are precursors which are transformed during the brewing process into important bittering, aromatising and preservative components with rather low efficiency. By selectively transforming these components off-line, both their utilisation efficiency and functionality can be significantly improved. Therefore, the chemical transformations of these secondary metabolites will be considered with special attention to recent advances in the field. The considered components are the hop alpha-acids, hop beta-acids and xanthohumol, which are components unique to hops, and alpha-humulene and beta-caryophyllene, sesquiterpenes which are highly characteristic of hops.
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Affiliation(s)
- Bart Steenackers
- Centre for Surface Science and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium
| | - Luc De Cooman
- Laboratory for Enzyme and Brewing Technology, KaHo St.-Lieven, Gebroeders Desmetstraat 1, 9000 Gent, Belgium
| | - Dirk De Vos
- Centre for Surface Science and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
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34
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Pickrahn S, Sebald K, Hofmann T. Application of 2D-HPLC/taste dilution analysis on taste compounds in aniseed (Pimpinella anisum L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:9239-9245. [PMID: 25186288 DOI: 10.1021/jf502896n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This is the first application of fully automated, preparative, two-dimensional HPLC combined with sensory analysis for taste compound discovery using a sweet and licorice-like bitter-tasting aniseed extract as an example. Compared to the traditional iterative fractionation of food extracts by sensory-guided sequential application of separation techniques, the fully automated 2D-HPLC allowed the comprehensive separation of the aniseed extract into 256 subfractions and reduced the fractionation time from about 1 week to <1day. Using a smart sensory strategy to locate high-impact fractions, e.g., by evaluating first-dimension fractions by reconstituting them from second-dimension subfractions, followed by straightforward application of the taste dilution analysis on the individual second-dimension subfractions revealed the sweet-tasting trans-anethole and the bitter-tasting trans-pseudoisoeugenol 2-methylbutyrate, showing recognition thresholds of 70 and 68 μmol/L, respectively, as the primary orosensory active compounds in aniseed. 2D-HPLC combined with smart sensory analysis seems to be a promising strategy to speed the discovery of the key players imparting the attractive taste of foods.
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Affiliation(s)
- Stephen Pickrahn
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany
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35
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Blanco CA, Nimubona D, Caballero I. Prediction of the ageing of commercial lager beer during storage based on the degradation of iso-α-acids. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:1988-1993. [PMID: 24307135 DOI: 10.1002/jsfa.6513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/30/2013] [Accepted: 12/04/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Iso-α-acids and their chemically modified variants are responsible for the bitterness of beer and play a disproportionately large role in the final quality of beer. The current study was undertaken to predict the degradation of commercial lager beers related to changes in the concentration of trans-iso-α-acids during storage by using high-pressure liquid chromatography. RESULTS In the analysed beers the concentration of isohumulone (average concentration 28 mg L(-1)) was greater than that of isocohumulone (20 mg L(-1)) and isoadhumulone (10 mg L(-1)). The kinetic parameters, activation energy and rate constant, of the trans-iso-α-acids were calculated. In the case of dark beers, the activation energy for the degradation of trans-isocohumulones was found to be higher than for trans-isohumulones and trans-isoadhumulones, whereas in pale and alcohol-free beers activation energies for the degradation of the three trans isomers were similar. CONCLUSION The loss of iso-α-acids can be calculated using the activation energy of the degradation of trans-iso-α-acids and the temperature profile of the accelerated ageing. The results obtained in the investigation can be used in the beer industry to predict the alteration of the bitterness of beer during storage.
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Affiliation(s)
- Carlos A Blanco
- Dpto. Ingeniería Agrícola y Forestal (Tecnología de los Alimentos), E.T.S. Ingenierías Agrarias, 34004, Palencia, Universidad de Valladolid, Spain
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36
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Karabín M, Rýparová A, Jelínek L, Kunz T, Wietstock P, Methner FJ, Dostálek P. Relationship of iso-α-acid content and endogenous antioxidative potential during storage of lager beer. JOURNAL OF THE INSTITUTE OF BREWING 2014. [DOI: 10.1002/jib.140] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marcel Karabín
- Department of Biotechnology, Faculty of Food and Biochemical Technology; Institute of Chemical Technology Prague; Technická 5 166 28 Prague Czech Republic
| | - Alena Rýparová
- Department of Biotechnology, Faculty of Food and Biochemical Technology; Institute of Chemical Technology Prague; Technická 5 166 28 Prague Czech Republic
| | - Lukáš Jelínek
- Department of Biotechnology, Faculty of Food and Biochemical Technology; Institute of Chemical Technology Prague; Technická 5 166 28 Prague Czech Republic
| | - Thomas Kunz
- Institute of Food Technology and Food Chemistry; Technische Universität Berlin; Seestraße 13 13353 Berlin Germany
| | - Philip Wietstock
- Institute of Food Technology and Food Chemistry; Technische Universität Berlin; Seestraße 13 13353 Berlin Germany
| | - Frank-Jürgen Methner
- Institute of Food Technology and Food Chemistry; Technische Universität Berlin; Seestraße 13 13353 Berlin Germany
| | - Pavel Dostálek
- Department of Biotechnology, Faculty of Food and Biochemical Technology; Institute of Chemical Technology Prague; Technická 5 166 28 Prague Czech Republic
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37
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Rodda LN, Gerostamoulos D, Drummer OH. The stability of iso-α-acids and reduced iso-α-acids in stored blood specimens. Forensic Sci Int 2014; 239:44-9. [DOI: 10.1016/j.forsciint.2014.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/05/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
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38
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Cattoor K, Dresel M, De Bock L, Boussery K, Van Bocxlaer J, Remon JP, De Keukeleire D, Deforce D, Hofmann T, Heyerick A. Metabolism of hop-derived bitter acids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:7916-24. [PMID: 23898921 DOI: 10.1021/jf300018s] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In this study, in vitro metabolism of hop-derived bitter acids was investigated. Besides their well-known use as bitter compounds in beer, in several studies, bioactive properties have been related to these types of molecules. However, scientific data on the absorption, distribution, metabolism, and excretion aspects of these compounds are limited. More specific, in this study, α-acids, β-acids, and iso-α-acids were incubated with rabbit microsomes, and fractions were subjected to LC-MS/MS analysis for identification of oxidative biotransformation products. Metabolism of β-acids was mainly characterized by conversion into hulupones and the formation of a series of tricyclic oxygenated products. The most important metabolites of α-acids were identified as humulinones and hulupones. Iso-α-acids were found to be primarly metabolized into cis- and trans-humulinic acids, next to oxidized alloiso-α-acids. Interestingly, the phase I metabolites were highly similar to the oxidative degradation products in beer. These findings show a first insight into the metabolites of hop-derived bitter acids and could have important practical implications in the bioavailability aspects of these compounds, following ingestion of hop-based food products and nutraceuticals.
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Affiliation(s)
- Ko Cattoor
- Laboratory of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences, Ghent University (UGent), Ghent, Belgium.
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39
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Trigo-Mouriño P, Merle C, Koos MRM, Luy B, Gil RR. Probing Spatial Distribution of Alignment by Deuterium NMR Imaging. Chemistry 2013; 19:7013-9. [DOI: 10.1002/chem.201300254] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Indexed: 11/09/2022]
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40
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Taniguchi Y, Matsukura Y, Ozaki H, Nishimura K, Shindo K. Identification and quantification of the oxidation products derived from α-acids and β-acids during storage of hops ( Humulus lupulus L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:3121-30. [PMID: 23469991 DOI: 10.1021/jf3047187] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
α-Acids and β-acids, two main components of hop resin, are known to be susceptible to oxygen and degraded during hop storage, although the oxidation products in stored hops have not been fully identified. In this study, we developed a high-performance liquid chromatography (HPLC) analysis method suitable for separation and quantification of the oxidation products. This HPLC analysis clearly proved, for the first time, that humulinones and hulupones are major products in oxidized hops. We are also the first to identify novel 4'-hydroxy-allohumulinones, suggested to be oxidative products of humulinones, by means of NMR spectroscopy and high-resolution mass spectrometry. Using the developed analytical method, changes in α- and β-acids and their oxidation products during hop storage were clearly revealed for the first time.
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Affiliation(s)
- Yoshimasa Taniguchi
- Research Laboratories for Health Science & Food Technologies, Research & Development Division, KIRIN Company, Ltd. , 1-13-5, Fukuura, Kanagawa 236-0004, Japan.
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41
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Kruck M, Wadepohl H, Enders M, Gade LH. Giant Residual Dipolar13C-1H Couplings in High-Spin Organoiron Complexes: Elucidation of Their Structures in Solution by13C NMR Spectroscopy. Chemistry 2013; 19:1599-606. [DOI: 10.1002/chem.201203450] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Indexed: 11/11/2022]
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42
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Urban J, Dahlberg CJ, Carroll BJ, Kaminsky W. Absolute Configuration of Beer′s Bitter Compounds. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201208450] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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43
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Urban J, Dahlberg CJ, Carroll BJ, Kaminsky W. Absolute configuration of beer's bitter compounds. Angew Chem Int Ed Engl 2012; 52:1553-5. [PMID: 23239507 PMCID: PMC3563212 DOI: 10.1002/anie.201208450] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Jan Urban
- KinDex Therapeutics, 800 Fifth Avenue, Suite 4100, Seattle, WA 98104, USA
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44
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Tzvetkova P, Luy B, Simova S. Configuration verification via RDCs on the example of a tetra-substituted pyrrolidine ring. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50 Suppl 1:S92-S101. [PMID: 23280666 DOI: 10.1002/mrc.3902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 10/12/2012] [Accepted: 10/22/2012] [Indexed: 06/01/2023]
Abstract
The configurational analysis of organic compounds is an important application for high resolution NMR spectroscopy. In the present study, a tetra-substituted pyrrolidine with four chiral carbon atoms is analyzed using classical methods based on (3) J and NOE data in solution and compared and verified with recently introduced alternative approaches via residual dipolar couplings (RDCs) in two weak anisotropic alignment media. The molecule shows sufficient rigidity in the five-membered ring for the configurational characterization with the various techniques. However, the flexibility caused by the many freely rotating bonds potentially poses problems for the interpretation of data. It is shown that RDCs measured in poly-γ-benzyl-l-glutamate and a stretched polydimethylsiloxane gel provide useful information for the distinction of diastereomers, but the success varies with the data interpretation strategy used. Although a general improvement of corresponding correlation factors is observed when limiting data to a subset of dipolar couplings directly connected to the central ring, the distinction power is reduced because of the smaller number of RDCs available for potential model falsification. Singular value decomposition for fitting experimental RDCs is able to distinguish in most cases the correct from incorrect configurations, but the differences in correlation factors can be relatively small. Surprisingly, predicting RDCs using the rod model as implemented in PALES gives best results in distinguishing the eight possible diastereomers. It is also found that the use of proton-phosphorus and carbon-phosphorus RDCs helps with the configurational analysis of the model compound.
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Affiliation(s)
- Pavleta Tzvetkova
- Institute of Organic Chemistry and Institute for Biological Surfaces, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
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45
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Kobzar K, Ehni S, Skinner TE, Glaser SJ, Luy B. Exploring the limits of broadband 90° and 180° universal rotation pulses. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 225:142-160. [PMID: 23142001 DOI: 10.1016/j.jmr.2012.09.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/28/2012] [Indexed: 06/01/2023]
Abstract
90° and 180° universal rotation (UR) pulses are two of the most important classes of pulses in modern NMR spectroscopy. This article presents a systematic study characterizing the achievable performance of these pulses as functions of bandwidth, pulse length, and tolerance to B(1)-field inhomogeneity/miscalibration. After an evaluation of different quality factors employed in pulse design algorithms based on optimal control theory, resulting pulses are discussed in detail with a special focus on pulse symmetry. The vast majority of resulting BURBOP (broadband universal rotations by optimal control) pulses are either fully symmetric or have one symmetric and one antisymmetric Cartesian rf component, where the importance of the first symmetry has not been demonstrated yet and the latter one matches the symmetry that results from a previously derived construction principle of universal rotation pulses out of point-to-point pulses [3]. Optimized BURBOP pulses are shown to perform better than previously reported UR pulses, resulting in shorter pulse durations for the same quality of broadband rotations. From a comparison of qualities of effective universal rotations, we find that the application of a single optimal refocusing pulse matches or improves the performance of two consecutive inversion pulses in INEPT-like pulse sequence elements of the same total duration.
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Affiliation(s)
- Kyryl Kobzar
- Bruker Biospin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
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46
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Kaden P, Freudenberger JC, Luy B. Noncovalently and covalently cross-linked polyurethane gels as alignment media and the suppression of residual polymer signals using diffusion-filtered spectroscopy. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50 Suppl 1:S22-S28. [PMID: 23280657 DOI: 10.1002/mrc.3887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/03/2012] [Accepted: 09/20/2012] [Indexed: 06/01/2023]
Abstract
With polyurethane (PU), a novel alignment medium for organic solvents is introduced and characterized, which is very robust and easy to produce on a large scale. Linear PU already constitutes an elastomer gel with several solvents based on its ability to form hydrogen bonds. Covalent cross-linking of the polymer with accelerated electrons provides an alignment medium with different properties. However, PU exhibits a number of undesired polymer signals in corresponding spectra, which ideally have to be removed spectroscopically. Within this context, we demonstrate the applicability of diffusion-filtered experiments for removal of the polymer signals. Example spectra for the usefulness of PU alignment media are provided for the common test molecules strychnine and norcamphor.
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Affiliation(s)
- Peter Kaden
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal, Postfach 3640, 76021 Karlsruhe, Germany
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47
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De Clippeleer J, De Rouck G, De Cooman L, Aerts G. Influence of the Hopping Technology on the Storage-induced Appearance of Staling Aldehydes in Beer. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2010.tb00789.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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48
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Meyer NC, Krupp A, Schmidts V, Thiele CM, Reggelin M. Polyacetylenes as Enantiodifferentiating Alignment Media. Angew Chem Int Ed Engl 2012; 51:8334-8. [DOI: 10.1002/anie.201201891] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 06/22/2012] [Indexed: 11/05/2022]
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49
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Meyer NC, Krupp A, Schmidts V, Thiele CM, Reggelin M. Polyacetylenes as Enantiodifferentiating Alignment Media. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201891] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Caballero I, Blanco CA, Porras M. Iso-α-acids, bitterness and loss of beer quality during storage. Trends Food Sci Technol 2012. [DOI: 10.1016/j.tifs.2012.01.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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