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Fouotsa H, Mkounga P, Lannang AM, Vanheuverzwijn J, Zhou Z, Leblanc K, Rharrabti S, Nkengfack AE, Gallard JF, Fontaine V, Meyer F, Poupon E, Le Pogam P, Beniddir MA. Pyrrovobasine, hybrid alkylated pyrraline monoterpene indole alkaloid pseudodimer discovered using a combination of mass spectral and NMR-based machine learning annotations. Org Biomol Chem 2021; 20:98-105. [PMID: 34596204 DOI: 10.1039/d1ob01791h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A new vobasine-tryptamine-based monoterpene indole alkaloid pseudodimer was isolated from the stem bark of Voacanga africana. As a minor constituent occurring in a thoroughly investigated plant, this molecule was targeted based on a molecular networking strategy and a rational MS2-guided phytochemical investigation led to its isolation. Its structure was formally established based on HRMS, 1D/2D NMR data, and the application of the tool Small Molecule Accurate Recognition Technology (SMART 2.0). Its absolute configuration was assigned by the exciton chirality method and TD-DFT ECD calculations. Besides featuring an unprecedented intermonomeric linkage in the small group of vobasine/tryptamine hybrids, pyrrovobasine also represents the first pyrraline-containing representative in the whole monoterpene indole alkaloids group. Biosynthetic hypotheses possibly underpinning these structural oddities are proposed here.
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Affiliation(s)
- Hugues Fouotsa
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France. .,Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Campus de la Plaine-CP 206/04, Boulevard du Triomphe, ACC.2, Po Box 1050, Belgium.,Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Pierre Mkounga
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Alain Meli Lannang
- Department of Chemistry, Higher Teachers Training College, University of Maroua, P.O. Box 55, Maroua, Cameroon
| | - Jérôme Vanheuverzwijn
- Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Campus de la Plaine-CP 206/04, Boulevard du Triomphe, ACC.2, Po Box 1050, Belgium
| | - Zhiyu Zhou
- Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Campus de la Plaine-CP 206/04, Boulevard du Triomphe, ACC.2, Po Box 1050, Belgium
| | - Karine Leblanc
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France.
| | - Somia Rharrabti
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France.
| | - Augustin Ephrem Nkengfack
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Jean-François Gallard
- Institut de Chimie des Substances Naturelles, CNRS, ICSN UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Véronique Fontaine
- Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Campus de la Plaine-CP 206/04, Boulevard du Triomphe, ACC.2, Po Box 1050, Belgium
| | - Franck Meyer
- Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Campus de la Plaine-CP 206/04, Boulevard du Triomphe, ACC.2, Po Box 1050, Belgium
| | - Erwan Poupon
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France.
| | - Pierre Le Pogam
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France.
| | - Mehdi A Beniddir
- Équipe "Chimie des Substances Naturelles" Université Paris-Saclay, CNRS, BioCIS, 5 rue J.-B. Clément, 92290 Châtenay-Malabry, France.
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Fang Y, Yushmanov PV, Furó I. Assessing 2D electrophoretic mobility spectroscopy (2D MOSY) for analytical applications. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:584-588. [PMID: 27930812 PMCID: PMC5434926 DOI: 10.1002/mrc.4558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
Electrophoretic displacement of charged entity phase modulates the spectrum acquired in electrophoretic NMR experiments, and this modulation can be presented via 2D FT as 2D mobility spectroscopy (MOSY) spectra. We compare in various mixed solutions the chemical selectivity provided by 2D MOSY spectra with that provided by 2D diffusion-ordered spectroscopy (DOSY) spectra and demonstrate, under the conditions explored, a superior performance of the former method. 2D MOSY compares also favourably with closely related LC-NMR methods. The shape of 2D MOSY spectra in complex mixtures is strongly modulated by the pH of the sample, a feature that has potential for areas such as in drug discovery and metabolomics. Copyright © 2016 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.
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Affiliation(s)
- Yuan Fang
- Division of Applied Physical Chemistry, Department of ChemistryKTH Royal Institute of TechnologyTeknikringen 30SE‐10044StockholmSweden
| | | | - István Furó
- Division of Applied Physical Chemistry, Department of ChemistryKTH Royal Institute of TechnologyTeknikringen 30SE‐10044StockholmSweden
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Blunder M, Orthaber A, Bauer R, Bucar F, Kunert O. Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments. Food Chem 2017; 218:600-609. [DOI: 10.1016/j.foodchem.2016.09.077] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 09/11/2016] [Accepted: 09/12/2016] [Indexed: 12/21/2022]
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Laffy PW, Benkendorff K, Abbott CA. Suppressive subtractive hybridisation transcriptomics provides a novel insight into the functional role of the hypobranchial gland in a marine mollusc. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2013; 8:111-22. [PMID: 23422501 DOI: 10.1016/j.cbd.2013.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 01/18/2013] [Accepted: 01/18/2013] [Indexed: 11/28/2022]
Abstract
The hypobranchial gland present in gastropods is an organ whose function is not clearly understood. Involved in mucus production, within members of the family Muricidae it is also the source of the ancient dye Tyrian purple and its bioactive precursors. To gain further insights into hypobranchial gland biology, suppressive subtractive hybridisation was performed on hypobranchial gland and mantle tissue from the marine snail Dicathais orbita creating a differentially expressed cDNA library. 437 clones were randomly sequenced, analysed and annotated and 110 sequences had their functions putatively identified. Importantly this approach identified a putative gene involved in Tyrian purple biosynthesis, an arylsulphatase gene. Confirmation of the upregulation of arylsulphatase in the hypobranchial gland compared to the mantle was demonstrated using quantitative real-time PCR. Other genes identified as playing an important role in the hypobranchial gland were those involved in mucus protein synthesis, choline ester regulation, protein and energy production. This study confirms that the hypobranchial gland is involved in the production of mucus secretion and also identifies it as a site of chemical interaction and biosynthesis. This study lays the foundation for a better understanding of the enzymatic production of Tyrian purple precursors within the gland.
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Affiliation(s)
- Patrick W Laffy
- School of Biological Sciences, Flinders University, GPO Box 2100 Adelaide SA 5001, Australia.
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From single to multiple microcoil flow probe NMR and related capillary techniques: a review. Anal Bioanal Chem 2011; 402:647-69. [PMID: 21969176 DOI: 10.1007/s00216-011-5419-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/20/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most important and powerful instrumental analytical techniques for structural elucidation of unknown small and large (complex) isolated and synthesized compounds in organic and inorganic chemistry. X-ray crystallography, neutron scattering (neutron diffraction), and NMR spectroscopy are the only suitable methods for three-dimensional structure determination at atomic resolution. Moreover, these methods are complementary. However, by means of NMR spectroscopy, reaction dynamics and interaction processes can also be investigated. Unfortunately, this technique is very insensitive in comparison with other spectrometric (e.g., mass spectrometry) and spectroscopic (e.g., infrared spectroscopy) methods. Mainly through the development of stronger magnets and more sensitive solenoidal microcoil flow probes, this drawback has been successfully counteracted. Capillary NMR spectroscopy increases the mass-based sensitivity of the NMR spectroscopic analysis up to 100-fold compared with conventional 5-mm NMR probes, and thus can be coupled online and off-line with other microseparation and detection techniques. It offers not only higher sensitivity, but in many cases provides better quality spectra than traditional methods. Owing to the immense number of compounds (e.g., of natural product extracts and compound libraries) to be examined, single microcoil flow probe NMR spectroscopy will soon be far from being sufficiently effective as a screening method. For this reason, an inevitable trend towards coupled microseparation-multiple microcoil flow probe NMR techniques, which allow simultaneous online and off-line detection of several compounds, will occur. In this review we describe the current status and possible future developments of single and multiple microcoil capillary flow probe NMR spectroscopy and its application as a high-throughput tool for the analysis of a large number of mass-limited samples. The advantages and drawbacks of different coupled microseparation-capillary NMR spectroscopy techniques, such as capillary high-performance liquid chromatography-NMR spectroscopy, capillary electrophoresis-NMR spectroscopy, and capillary gas chromatography-NMR spectroscopy, are discussed and demonstrated by specific applications. Another subject of discussion is the progress in parallel NMR detection techniques. Furthermore, the applicability and mixing capability of tiny reactor systems, termed "microreactors" or "micromixers," implemented in NMR probes is demonstrated by carbamate- and imine-forming reactions.
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The efficient structure elucidation of minor components in heparin digests using microcoil NMR. Carbohydr Res 2011; 346:2244-54. [DOI: 10.1016/j.carres.2011.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/09/2011] [Indexed: 11/23/2022]
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Diekmann J, Adams KL, Klunder GL, Evans L, Steele P, Vogt C, Herberg JL. Portable Microcoil NMR Detection Coupled to Capillary Electrophoresis. Anal Chem 2011; 83:1328-35. [DOI: 10.1021/ac102389b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joana Diekmann
- Department of Analytical Chemistry, Institute of Inorganic Chemistry, Faculty of Natural Sciences, Leibniz University Hanover, Callinstrasse 1, 30167 Hanover, Germany
| | - Kristl L. Adams
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Gregory L. Klunder
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Lee Evans
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Paul Steele
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Carla Vogt
- Department of Analytical Chemistry, Institute of Inorganic Chemistry, Faculty of Natural Sciences, Leibniz University Hanover, Callinstrasse 1, 30167 Hanover, Germany
| | - Julie L. Herberg
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
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Ibuprofen metabolite profiling using a combination of SPE/column-trapping and HPLC-micro-coil NMR. J Pharm Biomed Anal 2007; 47:328-34. [PMID: 18276099 DOI: 10.1016/j.jpba.2007.12.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 12/13/2007] [Accepted: 12/18/2007] [Indexed: 11/22/2022]
Abstract
Solid-phase extraction and column-trapping preconcentration are combined to enhance HPLC-nuclear magnetic resonance (HPLC-NMR) and applied to metabolite profiling in biological samples. Combining the two signal enhancement techniques improved the NMR signal substantially such that we were able to identify 2-hydroxyibuprofen, carboxyibuprofen, and unmetabolized ibuprofen molecules from a small urine sample after a therapeutic dose of ibuprofen. The hyphenated SPE/column-trapping method resulted in an excellent overall signal enhancement of up to 90-fold.
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Edwards JL, Edwards RL, Reid KR, Kennedy RT. Effect of decreasing column inner diameter and use of off-line two-dimensional chromatography on metabolite detection in complex mixtures. J Chromatogr A 2007; 1172:127-34. [PMID: 17961581 PMCID: PMC2710303 DOI: 10.1016/j.chroma.2007.09.075] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 08/30/2007] [Accepted: 09/24/2007] [Indexed: 11/29/2022]
Abstract
Capillary liquid chromatography coupled with electrospray ionization to a quadrupole ion trap mass spectrometer was explored as a method for the analysis of polar anionic compounds in complex metabolome mixtures. A ternary mobile phase gradient, consisting of aqueous acidic, aqueous neutral and organic phases in combination with an aqueous compatible reversed-phase stationary phase allowed metabolites with a wide range of polarities to be resolved and detected. Detection limits in the full scan mode for glycolysis and tricarboxylic acid cycle intermediates were from 0.9 to 36fmol. Using this system, 111+/-9 (n=3) metabolites were detected in Escherichia coli lysate samples. Reducing column I.D. from 50 to 25microm increased the number of metabolites detected to 156+/-17 (n=3). The improvement in number of metabolites detected was attributed to an increase in separation efficiency, an increase in sensitivity, and a decrease in adduct formation. Implementation of a second separation mode, strong anion exchange, to fractionate the sample prior to capillary RPLC increased the number of metabolites detected to 244+/-21 (n=3). This improvement was attributed to the increased peak capacity which decreased co-elution of molecules enabling more sensitive detection by mass spectrometry. This system was also applied to islets of Langerhans where more significant improvements in metabolite detection were observed. In islets, 391+/-33 small molecules were detected using the two-dimensional separation. The results demonstrate that column miniaturization and use of two-dimensional separations can yield a significant improvement in the coverage of the metabolome.
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Affiliation(s)
- James L. Edwards
- Department of Chemistry University of Michigan Ann Arbor, MI USA
| | - Rachel L. Edwards
- Department of Microbiology and Immunology University of Michigan Ann Arbor, MI USA
| | - Kendra R. Reid
- Department of Chemistry University of Michigan Ann Arbor, MI USA
| | - Robert T. Kennedy
- Department of Chemistry University of Michigan Ann Arbor, MI USA
- Department of Pharmacology University of Michigan Ann Arbor, MI USA
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Eldridge SL, Almeida VK, Korir AK, Larive CK. Separation and Analysis of Trace Degradants in a Pharmaceutical Formulation Using On-Line Capillary Isotachophoresis-NMR. Anal Chem 2007; 79:8446-53. [DOI: 10.1021/ac7016629] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Stacie L. Eldridge
- Department of Chemistry, University of California, Riverside, California 92521, and Department of Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Valentino K. Almeida
- Department of Chemistry, University of California, Riverside, California 92521, and Department of Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Albert K. Korir
- Department of Chemistry, University of California, Riverside, California 92521, and Department of Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Cynthia K. Larive
- Department of Chemistry, University of California, Riverside, California 92521, and Department of Chemistry, University of Kansas, Lawrence, Kansas 66045
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Korir AK, Larive CK. On-line NMR detection of microgram quantities of heparin-derived oligosaccharides and their structure elucidation by microcoil NMR. Anal Bioanal Chem 2007; 388:1707-16. [PMID: 17607565 DOI: 10.1007/s00216-007-1400-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 05/20/2007] [Accepted: 05/24/2007] [Indexed: 10/23/2022]
Abstract
The isolation and purification of sufficient quantities of heparin-derived oligosaccharides for characterization by NMR is a tedious and time-consuming process. In addition, the structural complexity and microheterogeneity of heparin makes its characterization a challenging task. The improved mass-sensitivity of microcoil NMR probe technology makes this technique well suited for characterization of mass-limited heparin-derived oligosaccharides. Although microcoil probes have poorer concentration sensitivity than conventional NMR probes, this limitation can be overcome by coupling capillary isotachophoresis (cITP) with on-line microcoil NMR detection (cITP-NMR). Strategies to improve the sensitivity of on-line NMR detection through changes in probe design and in the cITP-NMR experimental protocol are discussed. These improvements in sensitivity allow acquisition of cITP-NMR survey spectra facilitating tentative identification of unknown oligosaccharides. Complete structure elucidation for microgram quantities of the purified material can be carried out through acquisition of 2D NMR spectra using a CapNMR microcoil probe.
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Affiliation(s)
- Albert K Korir
- Department of Chemistry, University of California, Riverside, CA 92521, USA.
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Schroeder FC, Gronquist M. Extending the scope of NMR spectroscopy with microcoil probes. Angew Chem Int Ed Engl 2007; 45:7122-31. [PMID: 16991159 DOI: 10.1002/anie.200601789] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Capillary NMR (CapNMR) spectroscopy has emerged as a major breakthrough for increasing the mass-sensitivity of NMR spectroscopic analysis and enabling the combination of NMR spectroscopy with other analytical techniques. Not only is the acquisition of high-sensitivity spectra getting easier but the quality of CapNMR spectra obtained in many small-molecule applications exceeds what can be accomplished with conventional designs. This Minireview discusses current CapNMR technology and its applications for the characterization of mass-limited, small-molecule and protein samples, the rapid screening of small-molecule or protein libraries, as well as hyphenated techniques that combine CapNMR with other analytical methods.
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Affiliation(s)
- Frank C Schroeder
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, MA 02115, USA.
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Abstract
ITP has been attracting constant attention for many years due to its principal capability to concentrate trace analytes by several orders of magnitude. In the current capillary format, it is able to concentrate trace analytes diluted to several microliters of an original sample into concentrated zones having volumes in the range of picoliters. Due to this reason, ITP holds an important position in many current multistage and multidimensional separation schemes. This article links up previous reviews on the topic and summarizes the progress of analytical capillary ITP since 2002. Almost 100 papers are reviewed that include methodological novelties, instrumental aspects, and analytical applications. Papers using ITP and/or isotachophoretic principles as part of multistage and/or multidimensional separation schemes are also included.
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Affiliation(s)
- Petr Gebauer
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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Petr J, Maier V, Horáková J, Sevcík J, Stránský Z. Capillary isotachophoresis from the student point of view – images and the reality. J Sep Sci 2006; 29:2705-15. [PMID: 17305231 DOI: 10.1002/jssc.200600249] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A review of some fundamental aspects of ITP from the student point of view, imaginations of some basic facts and laws, use of ITP, and the recent trends are presented. The results of theoretical computations of ITP separation processes are added for comparison of imaginations with the exact mathematical description.
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Affiliation(s)
- Jan Petr
- Department of Analytical Chemistrý, Palackỳ University, Trída Svobody 8, Olomouc, Czech Republic.
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Schroeder FC, Gronquist M. Größere Möglichkeiten für die NMR-Spektroskopie durch Mikrospulenprobenköpfe. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200601789] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Djukovic D, Liu S, Henry I, Tobias B, Raftery D. Signal enhancement in HPLC/microcoil NMR using automated column trapping. Anal Chem 2006; 78:7154-60. [PMID: 17037915 PMCID: PMC2577147 DOI: 10.1021/ac0605748] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new HPLC NMR system is described that performs analytical separation, preconcentration, and NMR spectroscopy in rapid succession. The central component of our method is the online preconcentration sequence that improves the match between postcolumn analyte peak volume and microcoil NMR detection volume. Separated samples are collected on to a C18 guard column with a mobile phase composed of 90% D2O/10% acetonitrile-D3 and back-flushed to the NMR microcoil probe with 90% acetonitrile-D3/10% D2O. To assess the performance of our unit, we separated a standard mixture of 1 mM ibuprofen, naproxen, and phenylbutazone using a commercially available C18 analytical column. The S/N measurements from the NMR acquisitions indicated that we achieved signal enhancement factors up to 10.4 (+/-1.2)-fold. Furthermore, we observed that preconcentration factors increased as the injected amount of analyte decreased. The highest concentration enrichment of 14.7 (+/-2.2)-fold was attained injecting 100 microL of solution of 0.2 mM (approximately 4 microg) ibuprofen.
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Affiliation(s)
- Danijel Djukovic
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette, IN 47907
| | - Shuhui Liu
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette, IN 47907
| | - Ian Henry
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette, IN 47907
| | | | - Daniel Raftery
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette, IN 47907
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Dossey AT, Walse SS, Rocca JR, Edison AS. Single insect NMR: A new tool to probe chemical biodiversity. ACS Chem Biol 2006; 1:511-4. [PMID: 17168538 DOI: 10.1021/cb600318u] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Because of analytical limitations, multiple animals or plants are typically required to identify natural products. Using a unique 1-mm high-temperature superconducting NMR probe, we directly examined the chemical composition of defensive secretions from walking stick insects. Individual milkings were dissolved in D2O without purification and examined by NMR within 10 min of secretion. We found that Anisomorpha buprestoides secretes similar quantities of glucose and mixtures of monoterpene dialdehydes that are stereoisomers of dolichodial. Different individual animals produce different stereoisomeric mixtures, the ratio of which varies between individual animals raised in the same container and fed the same food. Another walking stick, Peruphasma schultei, also secretes glucose and a single, unique stereoisomer that we are naming "peruphasmal". These observations suggest a previously unrecognized significance of aqueous components in walking stick defensive sprays. Single-insect variability of venom demonstrates the potential importance of chemical biodiversity at the level of individual animals.
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