1
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Hwang TL, Yang N, Cheng G, Chen Y, Cui S. Application of 1D 15 N and band-selective 2D 1 H- 15 N CLIP-HSQMBC to detect 35/37 Cl isotope effect on nitrogen for unequivocal structure elucidation of the N-Cl moiety in molecules. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2022; 60:157-164. [PMID: 34376016 DOI: 10.1002/mrc.5204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 08/04/2021] [Accepted: 08/08/2021] [Indexed: 06/13/2023]
Abstract
An impurity, designated MS204, was isolated from a scale-up production of an intermediate toward the synthesis of an active pharmaceutical ingredient. Structural elucidation of this chloro-containing impurity was performed based on the analysis of the MS and NMR data. Band-selective 2D 1 H-15 N CLIP-HSQMBC experiment was developed to unequivocally identify the ionic N-Cl moiety in the molecule by discovering the two isotope-shifted nitrogen peaks as 3 to 1 ratio separated by about 1 Δ15 N(37/35 Cl) = 19.6 ppb (1.19 Hz) due to the Cl isotope effect. 1D 15 N and 2D 1 H-15 N CLIP-HSQMBC experiments were applied to commercially available compounds to further confirm the techniques by detecting the isotope shift of nitrogen peaks for the N-Cl moiety in molecules.
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Affiliation(s)
| | - Ning Yang
- Attribute Sciences, Amgen Inc., Thousand Oaks, CA, USA
| | - Guilong Cheng
- Attribute Sciences, Amgen Inc., Thousand Oaks, CA, USA
- Department of Analytical Development and QC, Foghorn Therapeutics, Cambridge, MA, USA
| | - Ying Chen
- Drug Substance Technologies, Amgen Inc., Thousand Oaks, CA, USA
- Chemical Development, CMC, Neurocrine Biosciences, San Diego, CA, USA
| | - Sheng Cui
- Drug Substance Technologies, Amgen Inc., Thousand Oaks, CA, USA
- CMC, New Amsterdam Pharma, Miami, FL, USA
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2
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Charlier C, Cox N, Prud'homme S, Geffard A, Nuzillard JM, Luy B, Lippens G. Virtual decoupling to break the simplification versus resolution trade-off in nuclear magnetic resonance of complex metabolic mixtures. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:619-627. [PMID: 37905230 PMCID: PMC10539796 DOI: 10.5194/mr-2-619-2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/19/2021] [Indexed: 11/01/2023]
Abstract
The heteronuclear single quantum correlation (HSQC) experiment developed by Bodenhausen and Ruben (1980) in the early days of modern nuclear magnetic resonance (NMR) is without a doubt one of the most widely used experiments, with applications in almost every aspect of NMR including metabolomics. Acquiring this experiment, however, always implies a trade-off: simplification versus resolution. Here, we present a method that artificially lifts this barrier and demonstrate its application towards metabolite identification in a complex mixture. Based on the measurement of clean in-phase and clean anti-phase (CLIP/CLAP) HSQC spectra (Enthart et al., 2008), we construct a virtually decoupled HSQC (vd-HSQC) spectrum that maintains the highest possible resolution in the proton dimension. Combining this vd-HSQC spectrum with a J -resolved spectrum (Pell and Keeler, 2007) provides useful information for the one-dimensional proton spectrum assignment and for the identification of metabolites in Dreissena polymorpha (Prud'homme et al., 2020).
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Affiliation(s)
- Cyril Charlier
- Toulouse Biotechnology Institute (TBI), Université de Toulouse,
CNRS, INRAE, INSA, Toulouse, France
| | - Neil Cox
- Toulouse Biotechnology Institute (TBI), Université de Toulouse,
CNRS, INRAE, INSA, Toulouse, France
| | - Sophie Martine Prud'homme
- Université de Reims Champagne-Ardenne (URCA), UMR-I 02 SEBIO
(Stress Environnementaux et Biosurveillance des milieux aquatiques), Moulin
de la Housse, Reims, France
- present address: Université de Lorraine, CNRS, LIEC, 57000, Metz, France
| | - Alain Geffard
- Université de Reims Champagne-Ardenne (URCA), UMR-I 02 SEBIO
(Stress Environnementaux et Biosurveillance des milieux aquatiques), Moulin
de la Housse, Reims, France
| | - Jean-Marc Nuzillard
- Université de Reims Champagne Ardenne, CNRS, ICMR UMR 7312, 51097 Reims, France
| | - Burkhard Luy
- Institute for Biological Interfaces 4 – Magnetic Resonance,
Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1,
76344 Eggenstein-Leopoldshafen, Germany
| | - Guy Lippens
- Toulouse Biotechnology Institute (TBI), Université de Toulouse,
CNRS, INRAE, INSA, Toulouse, France
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3
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García-Jiménez MJ, Gil-Caballero S, Maza S, Corzana F, Juárez-Vicente F, Miles JR, Sakamoto K, Kadomatsu K, García-Domínguez M, de Paz JL, Nieto PM. Midkine Interaction with Chondroitin Sulfate Model Synthetic Tetrasaccharides and Their Mimetics: The Role of Aromatic Interactions. Chemistry 2021; 27:12395-12409. [PMID: 34213045 PMCID: PMC8457220 DOI: 10.1002/chem.202101674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Indexed: 12/29/2022]
Abstract
Midkine (MK) is a neurotrophic factor that participates in the embryonic central nervous system (CNS) development and neural stem cell regulation, interacting with sulfated glycosaminoglycans (GAGs). Chondroitin sulfate (CS) is the natural ligand in the CNS. In this work, we describe the interactions between a library of synthetic models of CS‐types and mimics. We did a structural study of this library by NMR and MD (Molecular Dynamics), concluding that the basic shape is controlled by similar geometry of the glycosidic linkages. Their 3D structures are a helix with four residues per turn, almost linear. We have studied the tetrasaccharide‐midkine complexes by ligand observed NMR techniques and concluded that the shape of the ligands does not change upon binding. The ligand orientation into the complex is very variable. It is placed inside the central cavity of MK formed by the two structured beta‐sheets domains linked by an intrinsically disordered region (IDR). Docking analysis confirmed the participation of aromatics residues from MK completed with electrostatic interactions. Finally, we test the biological activity by increasing the MK expression using CS tetrasaccharides and their capacity in enhancing the growth stimulation effect of MK in NIH3T3 cells.
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Affiliation(s)
- María José García-Jiménez
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain
| | - Sergio Gil-Caballero
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain.,Current Address: Universitat de Girona, Edifici Jaume Casademont Porta E, Parc Científic, Girona, Spain
| | - Susana Maza
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain
| | - Francisco Corzana
- Department of Chemistry, University of La Rioja, Logroño (La Rioja), Spain
| | - Francisco Juárez-Vicente
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, C/ Américo Vespucio, 24, 41092, Sevilla, Spain
| | - Jonathan R Miles
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain
| | - Kazuma Sakamoto
- Institute for Glyco-core Research (iGCORE), Departments of Biochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Kenji Kadomatsu
- Institute for Glyco-core Research (iGCORE), Departments of Biochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Mario García-Domínguez
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, CSIC-Universidad de Sevilla-Universidad Pablo de Olavide, C/ Américo Vespucio, 24, 41092, Sevilla, Spain
| | - José L de Paz
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain
| | - Pedro M Nieto
- Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), cicCartuja, CSIC, Universidad de Sevilla, C/ Américo Vespucio, 49, 41092, Sevilla, Spain
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4
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Dubey A, Takeuchi K, Reibarkh M, Arthanari H. The role of NMR in leveraging dynamics and entropy in drug design. JOURNAL OF BIOMOLECULAR NMR 2020; 74:479-498. [PMID: 32720098 PMCID: PMC7686249 DOI: 10.1007/s10858-020-00335-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/11/2020] [Indexed: 05/03/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy has contributed to structure-based drug development (SBDD) in a unique way compared to the other biophysical methods. The potency of a ligand binding to a protein is dictated by the binding free energy, which is an intricate interplay between entropy and enthalpy. In addition to providing the atomic resolution structural information, NMR can help to identify protein-ligand interactions that potentially contribute to the enthalpic component of the free energy. NMR can also illuminate dynamic aspects of the interaction, which correspond to the entropic term of the free energy. The ability of NMR to access both terms in the free energy equation stems from the suite of experiments developed to shed light on various aspects that contribute to both entropy and enthalpy, deepening our understanding of the biological function of macromolecules and assisting to target them in physiological conditions. Here we provide a brief account of the contribution of NMR to SBDD, highlighting hallmark examples and discussing the challenges that demand further method development. In the era of integrated biology, the unique ability of NMR to directly ascertain structural and dynamical aspects of macromolecule and monitor changes in these properties upon engaging a ligand can be combined with computational and other structural and biophysical methods to provide a more complete picture of the energetics of drug engagement with the target. Such efforts can be used to engineer better drugs.
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Affiliation(s)
- Abhinav Dubey
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Koh Takeuchi
- Cellular and Molecular Biotechnology Research Institute & Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan.
| | - Mikhail Reibarkh
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Haribabu Arthanari
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA.
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5
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Wang W, Yang J, Liao YY, Cheng G, Chen J, Mo S, Yuan L, Cheng XD, Qin JJ, Shao Z. Aspeterreurone A, a Cytotoxic Dihydrobenzofuran-Phenyl Acrylate Hybrid from the Deep-Sea-Derived Fungus Aspergillus terreus CC-S06-18. JOURNAL OF NATURAL PRODUCTS 2020; 83:1998-2003. [PMID: 32489099 DOI: 10.1021/acs.jnatprod.0c00189] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A new dihydrobenzofuran-phenyl acrylate hybrid, aspeterreurone A (1), was obtained from the culture of the deep-sea-derived fungus Aspergillus terreus CC-S06-18. The relative configuration of 1 was elucidated by HSQMBC NMR, calculated NMR chemical shifts coupled with a statistical procedure (DP4+), and the absolute configuration was established by ECD calculations. 1 exhibited cytotoxicities against the gastric cancer cell lines HGC27, MGC803, BGC823, and AGS, with minimal effects on normal gastric epithelial cell line GES-1. Further studies showed that 1 inhibited cell cycle progression and induced apoptosis of gastric cancer MGC803 cells in a concentration-dependent manner. Western blot analysis indicated that 1 inhibited the phosphorylation of STAT3, which might contribute to its cytotoxic activity.
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Affiliation(s)
- Weiyi Wang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 184 Daxue Road, Xiamen 361005, People's Republic of China
| | - Jing Yang
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
| | - Yan-Yan Liao
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, People's Republic of China
| | - Gang Cheng
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
| | - Jing Chen
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
| | - Shaowei Mo
- First Clinical Medical College, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
| | - Li Yuan
- First Clinical Medical College, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
| | - Xiang-Dong Cheng
- Institute of Cancer and Basic Medicine, Chinese Academy of Zhejiang Cancer Hospital, Banshan Road 1#, Hangzhou 310022, People's Republic of China
| | - Jiang-Jiang Qin
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, People's Republic of China
- Institute of Cancer and Basic Medicine, Chinese Academy of Zhejiang Cancer Hospital, Banshan Road 1#, Hangzhou 310022, People's Republic of China
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 184 Daxue Road, Xiamen 361005, People's Republic of China
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6
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Saurí J, Nolis P, Parella T. How to measure long-range proton-carbon coupling constants from 1 H-selective HSQMBC experiments. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:363-375. [PMID: 32239575 DOI: 10.1002/mrc.4928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/27/2019] [Accepted: 07/18/2019] [Indexed: 06/11/2023]
Abstract
Heteronuclear long-range scalar coupling constants (n JCH ) are a valuable tool for solving problems in organic chemistry and are especially suited for stereochemical and configurational analyses of small molecules and natural products. This tutorial will focus on the step-by-step implementation of several 2D 1 H frequency selective HSQMBC experiments for the easy and accurate measurement of either the magnitude or both the magnitude and the sign of long-range n JCH couplings. The performance of these experiments will be showcased with several scenarios in a range of different experimental conditions.
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Affiliation(s)
- Josep Saurí
- Structure Elucidation Group, Analytical Research and Development, Merck & Co., Inc., Boston, MA
| | - Pau Nolis
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, Barcelona, Spain
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7
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Motiram-Corral K, Nolis P, Saurí J, Parella T. LR-HSQMBC versus LR-selHSQMBC: Enhancing the Observation of Tiny Long-Range Heteronuclear NMR Correlations. JOURNAL OF NATURAL PRODUCTS 2020; 83:1275-1282. [PMID: 32155071 DOI: 10.1021/acs.jnatprod.0c00058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The detection of ultra-long-range (4JCH and higher) heteronuclear connectivities can complement the conventional use of HMBC/HSQMBC data in structure elucidation NMR studies of proton-deficient natural products, where two-bond and three-bond correlations are usually observed. The performance of the selHSQMBC experiment with respect to its broadband HSQMBC counterpart is evaluated. Despite its frequency-selectivity nature, selHSQMBC efficiently prevents any unwanted signal phase and intensity modulations due to passive proton-proton coupling constants typically involved in HSQMBC. As a result, selHSQMBC offers a significant sensitivity enhancement and provides pure in-phase multiplets, improving the detection levels for short- and long-range cross-peaks corresponding to small heteronuclear coupling values. This is particularly relevant for experiments optimized to small nJCH values (2-3 Hz), referred to as LR-selHSQMBC, where key cross-peaks that are not visible in the equivalent broadband LR-HSQMBC spectrum can become observable in optimum conditions.
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Affiliation(s)
- Kumar Motiram-Corral
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Catalonia, Spain
| | - Pau Nolis
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Catalonia, Spain
| | - Josep Saurí
- Structure Elucidation Group, Analytical Research & Development, Merck & Co., Inc., 33 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Catalonia, Spain
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8
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Motiram-Corral K, Souza AA, Saurí J, Nolis P, Parella T. LR-selHSQMBC: Simultaneous Detection and Quantification of Very Weak Long-Range Heteronuclear NMR Correlations. Chemphyschem 2020; 21:280-283. [PMID: 31951093 DOI: 10.1002/cphc.201901142] [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: 12/03/2019] [Revised: 01/10/2020] [Indexed: 11/08/2022]
Abstract
The optimum detection and accurate measurement of longer-range (4 J and higher) heteronuclear NMR correlations is described. The magnitude and/or the sign of a wide range of large and small long-range couplings can be simultaneously determined for protonated and non-protonated 13 C and 15 N nuclei using the LR-selHSQMBC experiment.
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Affiliation(s)
- Kumar Motiram-Corral
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Catalonia, Spain
| | - Alexandre A Souza
- Departamento de Química, Universidade Federal de Piauí, 64049-550, Teresina" PI, Brazil
| | - Josep Saurí
- Structure Elucidation Group, Analytical Research & Development, Merck & Co., Inc., 33 Av. Louis Pasteur, Boston, MA, 02215, USA
| | - Pau Nolis
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Catalonia, Spain
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Catalonia, Spain
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9
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Stachelska-Wierzchowska A, Wierzchowski J, Górka M, Bzowska A, Stolarski R, Wielgus-Kutrowska B. Tricyclic Nucleobase Analogs and Their Ribosides as Substrates and Inhibitors of Purine-Nucleoside Phosphorylases III. Aminopurine Derivatives. Molecules 2020; 25:E681. [PMID: 32033464 PMCID: PMC7037862 DOI: 10.3390/molecules25030681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/24/2020] [Accepted: 01/30/2020] [Indexed: 11/16/2022] Open
Abstract
Etheno-derivatives of 2-aminopurine, 2-aminopurine riboside, and 7-deazaadenosine (tubercidine) were prepared and purified using standard methods. 2-Aminopurine reacted with aqueous chloroacetaldehyde to give two products, both exhibiting substrate activity towards bacterial (E. coli) purine-nucleoside phosphorylase (PNP) in the reverse (synthetic) pathway. The major product of the chemical synthesis, identified as 1,N2-etheno-2-aminopurine, reacted slowly, while the second, minor, but highly fluorescent product, reacted rapidly. NMR analysis allowed identification of the minor product as N2,3-etheno-2-aminopurine, and its ribosylation product as N2,3-etheno-2-aminopurine-N2--D-riboside. Ribosylation of 1,N2-etheno-2-aminopurine led to analogous N2--d-riboside of this base. Both enzymatically produced ribosides were readily phosphorolysed by bacterial PNP to the respective bases. The reaction of 2-aminopurine-N9- -D-riboside with chloroacetaldehyde gave one major product, clearly distinct from that obtained from the enzymatic synthesis, which was not a substrate for PNP. A tri-cyclic 7-deazaadenosine (tubercidine) derivative was prepared in an analogous way and shown to be an effective inhibitor of the E. coli, but not of the mammalian enzyme. Fluorescent complexes of amino-purine analogs with E. coli PNP were observed.
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Affiliation(s)
| | - Jacek Wierzchowski
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland;
| | - Michał Górka
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 5 Pasteura St., 02-093 Warsaw, Poland; (M.G.); (A.B.); (R.S.)
- Biological and Chemical Research Centre, University of Warsaw, 101 Zwirki i Wigury St., 02-089 Warsaw, Poland
| | - Agnieszka Bzowska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 5 Pasteura St., 02-093 Warsaw, Poland; (M.G.); (A.B.); (R.S.)
| | - Ryszard Stolarski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 5 Pasteura St., 02-093 Warsaw, Poland; (M.G.); (A.B.); (R.S.)
| | - Beata Wielgus-Kutrowska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 5 Pasteura St., 02-093 Warsaw, Poland; (M.G.); (A.B.); (R.S.)
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10
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Moreno A, Hansen KØ, Isaksson J. CSSF-CLIP-HSQMBC: measurement of heteronuclear coupling constants in severely crowded spectral regions. RSC Adv 2019; 9:36082-36087. [PMID: 35540578 PMCID: PMC9074913 DOI: 10.1039/c9ra04118d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/18/2019] [Indexed: 11/21/2022] Open
Abstract
A new pulse program development, a chemical shift selective filtration clean in-phase HSQMBC (CSSF-CLIP-HSQMBC), is presented for the user-friendly measurement of long-range heteronuclear coupling constants in severely crowded spectral regions. The introduction of the chemical shift selective filter makes the experiment extremely efficient at resolving overlapped multiplets and produces a clean selective CLIP-HSQMBC spectrum, in which the desired coupling constants can easily be measured as an extra proton-carbon splitting in f2. The pulse sequence is also provided as a real-time homonuclear decoupled version in which the heteronuclear coupling constant can be directly measured as the peak splitting in f2. The same principle is readily applicable to IPAP and AP versions of the same sequence as well as the optional TOCSY transfer, or in principle to any other selective heteronuclear experiment that relies on a clean 1H multiplet.
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Affiliation(s)
- Aitor Moreno
- Bruker BioSpin AG, Application Science Department CH-8117 Fällanden Switzerland
| | - Kine Østnes Hansen
- Marbio, UiT - The Arctic University of Norway Breivika NO-9037 Tromsø Norway
| | - Johan Isaksson
- Department of Chemistry, UiT - The Arctic University of Norway Breivika NO-9037 Tromsø Norway
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11
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Josa-Culleré L, Hirst MG, Lockett JP, Thompson AL, Moloney MG. Spirocyclic Tetramates by Sequential Knoevenagel and [1,5]-Prototropic Shift. J Org Chem 2019; 84:9671-9683. [PMID: 31276419 DOI: 10.1021/acs.joc.9b01345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Highly functionalized spirocyclic tetramates were prepared via a sequential Knoevenagel reaction and [1,5]-prototropic shift (T-reaction) of bicyclic tetramates. While these compounds isomerize in solution, stable analogues can be prepared via an appropriate choice of substituents. Further modification of these compounds allows for the introduction of aromatic groups, making them suitable as skeletons for application in medicinal chemistry.
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Affiliation(s)
- Laia Josa-Culleré
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Michael G Hirst
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Jonathan P Lockett
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Amber L Thompson
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Mark G Moloney
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K.,Oxford Suzhou Centre for Advanced Research , Building A, 388 Ruo Shui Road, Suzhou Industrial Park , Jiangsu 215123 , P. R. China
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12
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Sevenich A, Mark PS, Behrendt T, Groß J, Opatz T. Synthesis of 2,3-Dihydro-4-pyridones, 4-Quinolones, and 2,3-Dihydro-4-azocinones by Visible-Light Photocatalytic Aerobic Dehydrogenation. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900584] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Adrian Sevenich
- Institute of Organic Chemistry; Johannes Gutenberg University; Duesbergweg 10-14 55128 Mainz Germany
| | - Paulina Sophie Mark
- Institute of Organic Chemistry; Johannes Gutenberg University; Duesbergweg 10-14 55128 Mainz Germany
| | - Torsten Behrendt
- Institute of Organic Chemistry; Johannes Gutenberg University; Duesbergweg 10-14 55128 Mainz Germany
| | - Jonathan Groß
- Institute of Organic Chemistry; Johannes Gutenberg University; Duesbergweg 10-14 55128 Mainz Germany
| | - Till Opatz
- Institute of Organic Chemistry; Johannes Gutenberg University; Duesbergweg 10-14 55128 Mainz Germany
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13
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Stewart NJ, Kumeta H, Tomohiro M, Hashimoto T, Hatae N, Matsumoto S. Long-range heteronuclear J-coupling constants in esters: Implications for 13C metabolic MRI by side-arm parahydrogen-induced polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 296:85-92. [PMID: 30223155 DOI: 10.1016/j.jmr.2018.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/28/2018] [Accepted: 08/28/2018] [Indexed: 06/08/2023]
Abstract
Side-arm parahydrogen induced polarization (PHIP-SAH) presents a cost-effective method for hyperpolarization of 13C metabolites (e.g. acetate, pyruvate) for metabolic MRI. The timing and efficiency of typical spin order transfer methods including magnetic field cycling and tailored RF pulse sequences crucially depends on the heteronuclear J coupling network between nascent parahydrogen protons and 13C, post-parahydrogenation of the target compound. In this work, heteronuclear nJHC (1 < n ≤ 5) couplings of acetate and pyruvate esters pertinent for PHIP-SAH were investigated experimentally using selective HSQMBC-based pulse sequences and numerically using DFT simulations. The CLIP-HSQMBC technique was used to quantify 2/3-bond JHC couplings, and 4/5-bond JHC ≲ 0.5 Hz were estimated by the sel-HSQMBC-TOCSY approach. Experimental and numerical (DFT-simulated) nJHC couplings were strongly correlated (P < 0.001). Implications for 13C hyperpolarization by magnetic field cycling, and PH-INEPT and ESOTHERIC type spin order transfer methods for PHIP-SAH were assessed, and the influence of direct nascent parahydrogen proton to 13C coupling when compared with indirect homonuclear TOCSY-type transfer through intermediate (non-nascent parahydrogen) protons was studied by the density matrix approach.
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Affiliation(s)
- Neil J Stewart
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Hiroyuki Kumeta
- Department of Structural Biology, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan; Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Mitsushi Tomohiro
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Takuya Hashimoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan; Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Noriyuki Hatae
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan
| | - Shingo Matsumoto
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan; JST, PREST, Saitama, Japan.
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14
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Dickson CL, Blundell CD, Butts CP, Felton A, Jeffreys A, Takacs Z. Accurate measurement of long range proton–carbon scalar coupling constants. Analyst 2017; 142:621-633. [DOI: 10.1039/c6an02298g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The accuracy and ease-of-use of various experimental NMR methods for measuringnJCHvalues is assessed.
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Affiliation(s)
| | | | | | - Alice Felton
- University of Bristol
- School of Chemistry
- Bristol
- UK
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15
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Pierens GK, Venkatachalam TK, Reutens DC. Investigation of two- and three-bond carbon-hydrogen coupling constants in cinnamic acid based compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:941-946. [PMID: 27356919 DOI: 10.1002/mrc.4469] [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: 04/11/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 06/06/2023]
Abstract
Two- and three-bond coupling constants (2 JHC and 3 JHC ) were determined for a series of 12 substituted cinnamic acids using a selective 2D inphase/antiphase (IPAP)-single quantum multiple bond correlation (HSQMBC) and 1D proton coupled 13 C NMR experiments. The coupling constants from two methods were compared and found to give very similar values. The results showed coupling constant values ranging from 1.7 to 9.7 Hz and 1.0 to 9.6 Hz for the IPAP-HSQMBC and the direct 13 C NMR experiments, respectively. The experimental values of the coupling constants were compared with discrete density functional theory (DFT) calculated values and were found to be in good agreement for the 3 JHC . However, the DFT method under estimated the 2 JHC coupling constants. Knowing the limitations of the measurement and calculation of these multibond coupling constants will add confidence to the assignment of conformation or stereochemical aspects of complex molecules like natural products. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Gregory K Pierens
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | | | - David C Reutens
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
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16
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Saurí J, Reibarkh M, Zhang T, Cohen RD, Wang X, Molinski TF, Martin GE, Williamson RT. Band-Selective 2D HSQMBC: A Universal Technique for Detection and Measurement of 35,37Cl Isotope Effects for 13C Nuclei. Org Lett 2016; 18:4786-4789. [DOI: 10.1021/acs.orglett.6b02158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Josep Saurí
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Mikhail Reibarkh
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Ting Zhang
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Ryan D. Cohen
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Xiao Wang
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Tadeusz F. Molinski
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - Gary E. Martin
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
| | - R. Thomas Williamson
- NMR Structure Elucidation, Process Research and Development and ‡Discovery Chemistry, MRL, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
- Department of Chemistry and Biochemistry and ∥Skaggs School of
Pharmacy and Pharmaceutical
Sciences, University of California, San Diego, 9500 Gilman Drive
MC-0358, La Jolla, California 92093, United States
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17
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Glanzer S, Kunert O, Zangger K. Determination of unresolved heteronuclear scalar coupling constants by J(up)-HSQMBC. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 268:88-94. [PMID: 27183090 DOI: 10.1016/j.jmr.2016.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 02/25/2016] [Accepted: 05/05/2016] [Indexed: 06/05/2023]
Abstract
Long-range heteronuclear scalar coupling constants provide important structural information, which is necessary for obtaining stereospecific assignment or dihedral angle information. The measurement of small proton-carbon splittings is particularly difficult due to the low natural abundance of carbon-13 and the presence of homonuclear couplings of similar size. Here we present a real-time J-upscaled HSQMBC, which allows the measurement of heteronuclear coupling constants even if they are hidden in the signal linewidth of a regular spectrum.
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Affiliation(s)
- Simon Glanzer
- Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Austria
| | - Olaf Kunert
- Institute of Pharmaceutical Sciences/Pharmaceutical Chemistry, University of Graz, Austria
| | - Klaus Zangger
- Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Austria.
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18
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Hwang TL, Bartberger MD, Chen Y. Application of 1,1-ADEQUATE, HMBC, and Density Functional Theory To Determine Regioselectivity in the Halogenation of Pyridine N-Oxides. Org Lett 2016; 18:1956-9. [DOI: 10.1021/acs.orglett.6b00370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tsang-Lin Hwang
- Attribute Sciences, ‡Molecular Engineering, Therapeutic Discovery, and §Drug Substance Technologies, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Michael D. Bartberger
- Attribute Sciences, ‡Molecular Engineering, Therapeutic Discovery, and §Drug Substance Technologies, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Ying Chen
- Attribute Sciences, ‡Molecular Engineering, Therapeutic Discovery, and §Drug Substance Technologies, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
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19
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Saurí J, Marcó N, Williamson RT, Martin GE, Parella T. Extending long-range heteronuclear NMR connectivities by HSQMBC-COSY and HSQMBC-TOCSY experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 258:25-32. [PMID: 26160012 DOI: 10.1016/j.jmr.2015.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 06/04/2023]
Abstract
The detection of long-range heteronuclear correlations presenting J(CH) coupling values smaller than 1-2Hz is a challenge in the structural analysis of small molecules and natural products. HSQMBC-COSY and HSQMBC-TOCSY pulse schemes are evaluated as complementary NMR methods to standard HMBC/HSQMBC experiments. Incorporation of an additional J(HH) transfer step in the basic HSQMBC pulse scheme can favor the sensitive observation of traditionally missing or very weak correlations and, in addition, facilitates the detection of a significant number of still longer-range connectivities to both protonated and non-protonated carbons under optimum sensitivity conditions. A comparative (1)H-(13)C study is performed using strychnine as a model compound and several examples are also provided including (1)H-(15)N applications.
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Affiliation(s)
- Josep Saurí
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain; NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Núria Marcó
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain
| | - R Thomas Williamson
- NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Gary E Martin
- NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
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20
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Saurí J, Nolis P, Parella T. Simultaneous determination of the magnitude and the sign of multiple heteronuclear coupling constants in 19F or 31P-containing compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:427-432. [PMID: 25891772 DOI: 10.1002/mrc.4239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/26/2015] [Accepted: 03/02/2015] [Indexed: 06/04/2023]
Abstract
The presence of a highly abundant passive nucleus (Z = 19F or 31P) allows the simultaneous determination of the magnitude and the sign of up to three different heteronuclear coupling constants from each individual cross-peak observed in a 2D 1H-X selHSQMBC spectrum. Whereas J(HZ) and J(XZ) coupling constants are measured from E.COSY multiplet patterns, J(XH) is independently extracted from the complementary IPAP pattern generated along the detected F2 dimension. The incorporation of an extended TOCSY transfer allows the extraction of a complete set of all these heteronuclear coupling constants and their signs for an entire 1H subspin system. 1H-X/1H-Y time-shared versions are also proposed for the simultaneous measurement of five different couplings (J(XH), J(YH), J(XZ), J(YZ), and J(ZH)) for multiple signals in a single NMR experiment.
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Affiliation(s)
- Josep Saurí
- Servei de Ressonància Magnètica Nuclear, Facultat de Ciències, Universitat Autònoma de Barcelona, Bellaterra, E-08193, Barcelona, Catalonia, Spain
| | - Pau Nolis
- Servei de Ressonància Magnètica Nuclear, Facultat de Ciències, Universitat Autònoma de Barcelona, Bellaterra, E-08193, Barcelona, Catalonia, Spain
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Facultat de Ciències, Universitat Autònoma de Barcelona, Bellaterra, E-08193, Barcelona, Catalonia, Spain
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21
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Saurí J, Sistaré E, Thomas Williamson R, Martin GE, Parella T. Implementing multiplicity editing in selective HSQMBC experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 252:170-175. [PMID: 25702573 DOI: 10.1016/j.jmr.2015.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/07/2015] [Accepted: 01/11/2015] [Indexed: 06/04/2023]
Abstract
Even C/CH(2) and odd CH/CH(3) carbon-multiplicity information can be directly distinguished from the relative positive/negative phase of cross-peaks in a novel ME (Multiplicity-Edited)-selHSQMBC experiment. The method can be extended by a TOCSY propagation step, and it is fully compatible for the simultaneous and precise determination of long-range heteronuclear coupling constants. Broadband homonuclear decoupling techniques can also be incorporated to enhance sensitivity and signal resolution by effective collapse of J(HH) multiplets.
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Affiliation(s)
- Josep Saurí
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, Facultat de Ciències, E-08193 Bellaterra (Barcelona), Catalonia, Spain; NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Eduard Sistaré
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, Facultat de Ciències, E-08193 Bellaterra (Barcelona), Catalonia, Spain
| | - R Thomas Williamson
- NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Gary E Martin
- NMR Structure Elucidation, Process and Analytical Chemistry, Merck & Co. Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, Facultat de Ciències, E-08193 Bellaterra (Barcelona), Catalonia, Spain.
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22
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Castañar L, Saurí J, Williamson RT, Virgili A, Parella T. Pure In-Phase Heteronuclear Correlation NMR Experiments. Angew Chem Int Ed Engl 2014; 53:8379-82. [DOI: 10.1002/anie.201404136] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Indexed: 11/09/2022]
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23
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Castañar L, Saurí J, Williamson RT, Virgili A, Parella T. Pure In-Phase Heteronuclear Correlation NMR Experiments. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201404136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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24
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Williamson RT, Buevich AV, Martin GE, Parella T. LR-HSQMBC: a sensitive NMR technique to probe very long-range heteronuclear coupling pathways. J Org Chem 2014; 79:3887-94. [PMID: 24708226 DOI: 10.1021/jo500333u] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
HMBC is one of the most often used and vital NMR experiments for the structure elucidation of organic and inorganic molecules. We have developed a new, high sensitivity NMR pulse sequence that overcomes the typical (2,3)JCH limitation of HMBC by extending the visualization of long-range correlation data to 4-, 5-, and even 6-bond long-range (n)JCH heteronuclear couplings. This technique should prove to be an effective experiment to complement HMBC for probing the structure of proton-deficient molecules. The LR-HSQMBC NMR experiment can, in effect, extend the range of HMBC to provide data similar to that afforded by 1,n-ADEQUATE even in sample-limited situations. This is accomplished by optimizing responses for very small (n)JCH coupings as opposed to relying on the markedly less sensitive detection of long-range coupled (13)C-(13)C homonuclear pairs at natural abundance. DFT calculations were employed to determine whether the very long-range correlations observed for cervinomycin A2 were reasonable on the basis of the calculated long-range couplings.
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Affiliation(s)
- R Thomas Williamson
- Discovery & Preclinical Sciences, Process & Analytical Chemistry, Structure Elucidation Group, Merck & Co. Inc. , Rahway, New Jersey 07065, United States
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25
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Castañar L, Saurí J, Nolis P, Virgili A, Parella T. Implementing homo- and heterodecoupling in region-selective HSQMBC experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 238:63-69. [PMID: 24316187 DOI: 10.1016/j.jmr.2013.10.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 10/27/2013] [Accepted: 10/28/2013] [Indexed: 06/02/2023]
Abstract
An NMR method to enhance the sensitivity and resolution in band-selective long-range heteronuclear correlation spectra is proposed. The excellent in-phase nature of the selHSQMBC experiment allows that homonuclear and/or heteronuclear decoupling can be achieved in the detected dimension of a 2D multiple-bond correlation map, obtaining simplified cross-peaks without their characteristic fine J multiplet structure. The experimental result is a resolution improvement while the highest sensitivity is also achieved. Specifically, it is shown that the (1)H-homodecoupled band-selective (HOBS) HSQMBC experiment represents a new way to measure heteronuclear coupling constants from the simplified in-phase doublets generated along the detected dimension.
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Affiliation(s)
- Laura Castañar
- Servei de Ressonància Magnètica Nuclear and Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Catalonia), Spain
| | - Josep Saurí
- Servei de Ressonància Magnètica Nuclear and Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Catalonia), Spain
| | - Pau Nolis
- Servei de Ressonància Magnètica Nuclear and Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Catalonia), Spain
| | - Albert Virgili
- Servei de Ressonància Magnètica Nuclear and Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Catalonia), Spain
| | - Teodor Parella
- Servei de Ressonància Magnètica Nuclear and Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Catalonia), Spain.
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