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Noleto-Dias C, Farag MA, Porzel A, Tavares JF, Wessjohann LA. A multiplex approach of MS, 1D-, and 2D-NMR metabolomics in plant ontogeny: A case study on Clusia minor L. organs (leaf, flower, fruit, and seed). Phytochem Anal 2024; 35:445-468. [PMID: 38069552 DOI: 10.1002/pca.3300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 10/09/2023] [Indexed: 04/13/2024]
Abstract
INTRODUCTION The genus Clusia L. is mostly recognised for the production of prenylated benzophenones and tocotrienol derivatives. OBJECTIVES The objective of this study was to map metabolome variation within Clusia minor organs at different developmental stages. MATERIAL AND METHODS In total 15 organs/stages (leaf, flower, fruit, and seed) were analysed by UPLC-MS and 1H- and heteronuclear multiple-bond correlation (HMBC)-NMR-based metabolomics. RESULTS This work led to the assignment of 46 metabolites, belonging to organic acids(1), sugars(2) phenolic acids(1), flavonoids(3) prenylated xanthones(1) benzophenones(4) and tocotrienols(2). Multivariate data analyses explained the variability and classification of samples, highlighting chemical markers that discriminate each organ/stage. Leaves were found to be rich in 5-hydroxy-8-methyltocotrienol (8.5 μg/mg f.w.), while flowers were abundant in the polyprenylated benzophenone nemorosone with maximum level detected in the fully mature flower bud (43 μg/mg f.w.). Nemorosone and 5-hydroxy tocotrienoloic acid were isolated from FL6 for full structural characterisation. This is the first report of the NMR assignments of 5-hydroxy tocotrienoloic acid, and its maximum level was detected in the mature fruit at 50 μg/mg f.w. Seeds as typical storage organ were rich in sugars and omega-6 fatty acids. CONCLUSION To the best of our knowledge, this is the first report on a comparative 1D-/2D-NMR approach to assess compositional differences in ontogeny studies compared with LC-MS exemplified by Clusia organs. Results derived from this study provide better understanding of the stages at which maximal production of natural compounds occur and elucidate in which developmental stages the enzymes responsible for the production of such metabolites are preferentially expressed.
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Affiliation(s)
- Clarice Noleto-Dias
- Natural and Synthetic Bioactive Products Graduate Program, Federal University of Paraíba, João Pessoa, PB, Brazil
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany
| | - Mohamed A Farag
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo, Egypt
| | - Andrea Porzel
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany
| | - Josean F Tavares
- Natural and Synthetic Bioactive Products Graduate Program, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Ludger A Wessjohann
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany
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Altaib M, Doganc F, Kaşkatepe B, Göker H. Synthesis of some new 2-(substituted-phenyl)imidazo[4,5-c] and [4,5-b]pyridine derivatives and their antimicrobial activities. Mol Divers 2023:10.1007/s11030-023-10715-6. [PMID: 37642887 DOI: 10.1007/s11030-023-10715-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 08/07/2023] [Indexed: 08/31/2023]
Abstract
The synthesis of 5H-imidazo[4,5-c]pyridines analogues (1a - 1h) and 4H-imidazo[4,5-b]pyridines (3a - 3c) was achieved by reacting 3,4-diaminopyridine or 2,3-diaminopyridine with Na2S2O5 adduct of corresponding benzaldehydes (a1 - a8). Alkylation of compounds (1a - 1h) and (3a - 3c) using 4-chlorobenzyl and /or butyl bromide under basic conditions (K2CO3, DMF) predominantly resulted in the formation of N5 regioisomers (2a - 2l) and N4,3 regioisomers (4a - 4c1,2), respectively. The N5,4,3-regioisomeric structures were confirmed using 2D-NOESY (Nuclear Overhauser Effect Spectroscopy) and HMBC (Heteronuclear Multiple Bond Correlation) spectra. The antibacterial and antifungal activities of the synthesized compounds (2a - 2g, 4a - 5d) were evaluated in vitro against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Methicillin resistant S. aureus, Enterococcus faecalis and Candida albicans, Candida parapsilosis. Among the synthesized compounds, promising activities were observed with compounds 2g, 2h, 4a and 4b with lowest MIC values (4-8 µg/mL). The compounds 2i, 2j, 2k, 2l showed moderate activity. Additionally, a computational approach (ADMETlab 2.0) was used to evaluate the drug likeness properties of the compounds.
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Affiliation(s)
- Moftah Altaib
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Fatima Doganc
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Banu Kaşkatepe
- Department of Microbiology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Hakan Göker
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Ankara, Turkey.
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Bence Farkas L, Timári I, Kövér KE, Sørensen OW. Four-in-one: HSQC, HSQC-TOCSY (or H2BC), TOCSY, and enhanced HMBC spectra integrated into a single NO Relaxation Delay (NORD) NMR experiment. J Magn Reson 2022; 343:107297. [PMID: 36174396 DOI: 10.1016/j.jmr.2022.107297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/26/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
The NMR pulse sequence design strategy of NORD (NO Relaxation Delay) is extended to design of two new three-module experiments, NORD {HMBC}-{HSQC-TOCSY}-{TOCSY} and NORD {HMBC}-{2BOB}-{TOCSY}, each delivering four spectra - HMBC, HSQC, TOCSY, and either HSQC-TOCSY or H2BC. Compared to individual recording of these spectra particularly the sensitivity of the least sensitive module, HMBC, is enhanced by designing the homonuclear TOCSY module to allow buildup of magnetization pertinent to HMBC during its execution. Effectively, the sensitivity of the heteronuclear modules is boosted at the expense of the inherently much higher TOCSY sensitivity, thus resulting in a significant saving in spectrometer time.
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Affiliation(s)
- László Bence Farkas
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - István Timári
- Department of Organic Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Katalin E Kövér
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; MTA-DE Molecular Recognition and Interaction Research Group, University of Debrecen, Hungary.
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Ozokan KG, Kaban S. Synthesis and Structure of Hetaryl Substituted 2,5-dioxo-1,2,3,4,5,6,7,8- Octahydroquinolines. Curr Org Synth 2022; 19:664-672. [PMID: 35388760 DOI: 10.2174/1570179419666220406233307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/20/2021] [Accepted: 12/17/2021] [Indexed: 11/22/2022]
Abstract
AIMS AND OBJECTIVE Condensation of 5-hetarylidene-2,2-dimethyl-1,3-dioxane-4,6-diones with 5,5-dimethyl-3-arylamino-2-cyclohexanones yields 1-aryl-4-hetaryl-7,7-dimethyl-2,5-dioxo-l,2,3,4,5,5,7,8-octahydro-quinolines. The structures of all the synthesized compounds have been verified by IR, 1H-NMR, 13C-NMR, and mass spectral methods. The 13C-NMR assignments were supported by HSQC and HMBC experiments. Moreover, spin decoupling and NOE experiments have been carried out in order to elucidate stereoisomeric configurations of the compounds. It has been established that the N-phenyl ring, which projects from the plane of the octahydroquinolinedione ring, has a shielding effect on the magnetic field of the protons at 7- and 8-positions of the ring in the molecules of the compounds synthesized. MATERIALS AND METHODS The NMR spectra were recorded on a Varian Gemini spectrometer [400 MHz (1H) and 100 MHz (13C)]. EI mass spectra were obtained with a Hewlett Packard GC/MS 6890/5973 machine. MALDI-TOF mass measurements were recorded on a Bruker auto-flex III smart beam. RESULTS Various reaction conditions were applied in order to find an optimum and convenient procedure for the formation of octahydroquinoline derivates having hetaryl group. The highest yields (40-50 %) were achieved using acetic acid as solvent, p-toluenesulphonic acid as acidic catalyst, and excess enaminone (1.5 equiv). CONCLUSION We synthesized eight new 1-aryl-7,7-dimethyl-4-hetaryl-1,2,3,4,5,6,7,8-octahydro-quinoline-2,5-dione compounds containing thienyl core as a result of Michael addition reaction of Knoevenagel products of Meldrum's acid with dimedone enaminone compounds. Optimum circumstances were established using various reaction conditions and catalyzers throughout the research. The structures of all the synthesized compounds were analyzed by IR, 1H-NMR, 13C-NMR, and mass spectral methods. Furthermore, the structures were verified with the help of 2D (HSQC and HMBC), spin decoupling, and NOE NMR techniques.
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Affiliation(s)
- Kadri Gokhan Ozokan
- Department of Chemistry, Faculty of Science, Yildiz Technical University, Davutpasa Campus, Istanbul, 34220, Turkey
| | - Seniz Kaban
- Department of Chemistry, Faculty of Science, Yildiz Technical University, Davutpasa Campus, Istanbul, 34220, Turkey.,Department of Chemistry, Faculty of Science, Yildiz Technical University, Davutpasa Campus, Istanbul, 34220, Turkey
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Köck M, Lindel T, Junker J. Incorporation of 4J- HMBC and NOE Data into Computer-Assisted Structure Elucidation with WebCocon. Molecules 2021; 26:molecules26164846. [PMID: 34443433 PMCID: PMC8398166 DOI: 10.3390/molecules26164846] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/13/2023] Open
Abstract
Over the past decades, different software programs have been developed for the Computer-Assisted Structure Elucidation (CASE) with NMR data using with various approaches. WebCocon is one of them that has been continuously improved over the past 20 years. Here, we present the inclusion of 4JCH correlations (4J-HMBC) in the HMBC interpretation of Cocon and NOE data in WebCocon. The 4J-HMBC data is used during the structure generation process, while the NOE data is used in post-processing of the results. The marine natural product oxocyclostylidol was selected to demonstrate WebCocon’s enhanced HMBC data processing capabilities. A systematic study of the 4JCH correlations of oxocyclostylidol was performed. The application of NOEs in CASE is demonstrated using the NOE correlations of the diterpene pyrone asperginol A known from the literature. As a result, we obtained a conformation that corresponds very well to the existing X-ray structure.
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Affiliation(s)
- Matthias Köck
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570 Bremerhaven, Germany
- Correspondence: (M.K.); (J.J.)
| | - Thomas Lindel
- Institute of Organic Chemistry, Technical University of Braunschweig, 38106 Braunschweig, Germany;
| | - Jochen Junker
- Oswaldo Cruz Foundation–CDTS, Rio de Janeiro 21040-900, Brazil
- Correspondence: (M.K.); (J.J.)
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Namyslo JC, Drafz MHH, Kaufmann DE. Durable Modification of Wood by Benzoylation-Proof of Covalent Bonding by Solution State NMR and DOSY NMR Quick-Test. Polymers (Basel) 2021; 13:2164. [PMID: 34208957 PMCID: PMC8271922 DOI: 10.3390/polym13132164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 11/17/2022] Open
Abstract
A convenient, broadly applicable and durable wood protection was recently published by Kaufmann and Namyslo. This procedure efficiently allows for esterification of wood hydroxyl groups with (1H-benzotriazolyl)-activated functionalized benzoic acids. The result of such wood-modifying reactions is usually monitored by an increase in mass of the wood material (weight percent gain value, WPG) and by infrared spectroscopy (IR). However, diagnostic IR bands suffer from overlap with naturally occurring ester groups, mainly in the hemicellulose part of unmodified wood. In contrast to known NMR spectroscopy approaches that use the non-commonly available solid state techniques, herein we present solution state NMR proof of the covalent attachment of our organic precursors to wood. The finding is based on a time-efficient, non-uniformly sampled (NUS) solution state 1H,13C-HMBC experiment that only needs a tenth of the regular recording time. The appropriate NMR sample of thoroughly dissolved modified wood was prepared by a mild and non-destructive method. The 2D-HMBC shows a specific cross-signal caused by spin-spin coupling over three bonds from the ester carbonyl carbon atom to the α-protons of the esterified wood hydroxyl groups. This specific coupling pathway requires a covalent bonding as a conditio sine qua non. An even more rapid test to monitor the covalent bonding was achieved with an up-to-date diffusion-ordered spectroscopy sequence (Oneshot-DOSY) based on 1H or 19F as the sensitive nucleus. The control experiment in a series of DOSY spectra gave a by far higher D value of (1.22 ± 0.06)∙10-10 m2∙s-1, which is in accordance with fast diffusion of the "free" and thus rapidly moving small precursor molecule provided as its methyl ester. In the case of a covalent attachment to wood, a significantly smaller D value of (0.12 ± 0.01)∙10-10 m2∙s-1 was obtained.
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Affiliation(s)
| | | | - Dieter E. Kaufmann
- Institute of Organic Chemistry, Clausthal University of Technology, Leibnizstr. 6, 38678 Clausthal-Zellerfeld, Germany; (J.C.N.); (M.H.H.D.)
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Prasad D, Praveen A, Mahapatra S, Mogurampelly S, Chaudhari SR. Existence of β-diketone form of curcuminoids revealed by NMR spectroscopy. Food Chem 2021; 360:130000. [PMID: 33984567 DOI: 10.1016/j.foodchem.2021.130000] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/08/2021] [Accepted: 04/29/2021] [Indexed: 10/21/2022]
Abstract
Curcumin (CUR), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC) - the class of natural compound derived from turmeric can exist as keto-enol and β-diketone tautomer form. The structure and dynamics of particular relevance CUR is reported in prior studies, whereas DMC and BDMC, by far, have not been scrutinized. In the present studies, we have investigated the detailed molecular structure of CUR, DMC and BDMC by employing NMR spectroscopy as a key tool. The bridging carbon as methylene in β-diketone form and methine in keto-enol form shows significant difference in NMR spectrum. The results justified that Curcuminoids (CC) has nearly 3% of β-diketone tautomer in DMSO solvent at 298 K. Further, results revealed that β-diketone form was favoured in alkaline pH condition whereas acidic and neutral pH conditions favour keto-enol tautomer. However, at higher temperature equilibrium shift towards β-diketone tautomer. Moreover, this is the first report by NMR for observing the presence of β-diketone tautomer.
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Affiliation(s)
- Durga Prasad
- Department of Spice and Flavour Science, CSIR-Central Food Technological Research Institute, Mysore, Karnataka 570020, India
| | - Aishwarya Praveen
- Department of Spice and Flavour Science, CSIR-Central Food Technological Research Institute, Mysore, Karnataka 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sipra Mahapatra
- Department of Physics, Indian Institute of Technology Jodhpur, Karwar, Rajasthan 342037, India
| | - Santosh Mogurampelly
- Department of Physics, Indian Institute of Technology Jodhpur, Karwar, Rajasthan 342037, India
| | - Sachin R Chaudhari
- Department of Spice and Flavour Science, CSIR-Central Food Technological Research Institute, Mysore, Karnataka 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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Burns DC, Reynolds WF. Minimizing the risk of deducing wrong natural product structures from NMR data. Magn Reson Chem 2021; 59:500-533. [PMID: 33855734 DOI: 10.1002/mrc.4933] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 06/12/2023]
Abstract
There continues to be a disturbing number of natural products reported in the literature whose structures are incorrect. At least in part, this reflects the fact that many natural product chemists have limited formal nuclear magnetic resonance training. Gaps in training and lack of awareness regarding the challenges and ambiguities associated with two-dimensional nuclear magnetic resonance data interpretation can easily lead to errors in structure elucidation. The purpose of this tutorial is to point out some of these issues, highlight the kinds of errors that have been made and provide specific advice on how to avoid these missteps such that the risk of reporting a wrong structure is minimized.
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Affiliation(s)
- Darcy C Burns
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - William F Reynolds
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
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Perea-Buceta J, Rico Del Cerro D, Kilpeläinen I, Heikkinen S. Incorporated diffusion ordered heteronuclear multiple bond correlation spectroscopy, 3D iDOSY-HMBC. Merging of diffusion delay with long polarization transfer delay of HMBC. J Magn Reson 2021; 323:106892. [PMID: 33387959 DOI: 10.1016/j.jmr.2020.106892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
3D iDOSY-HMBC pulse sequences allow the simplification of HMBC data of mixtures via separation in the diffusion domain. The presented methods utilize incorporated DOSY approach, iDOSY, where the existing delays of the basic pulse sequence are utilized for diffusion attenuation. In the simplest form of the proposed 3D iDOSY-HMBC sequences, no extra delays or RF-pulses were required, only two diffusion gradients were added within HMBC polarization transfer delay.
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Affiliation(s)
- Jesus Perea-Buceta
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Daniel Rico Del Cerro
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Ilkka Kilpeläinen
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Sami Heikkinen
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
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Simonet AM, Durán AG, Pérez AJ, Macías FA. Features in the NMR spectra of the aglycones of Agave spp. saponins. HMBC method for aglycone identification (HMAI). Phytochem Anal 2021; 32:38-61. [PMID: 32515107 DOI: 10.1002/pca.2946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 05/08/2023]
Abstract
INTRODUCTION The analysis and detection of steroidal saponins is mainly performed using chromatographic techniques coupled with mass spectrometry. However, nuclear magnetic resonance (NMR) spectroscopy is a potential tool that can be combined with these techniques to obtain unambiguous structural characterisation. OBJECTIVE This work provides a review of the carbon-13 (13 C)- and proton (1 H)-NMR spectroscopic data of aglycones from Agave saponins reported in the literature and also the development of an easy identification method for these natural products. METHODS The database Scifinder was used for spectroscopic data collection in addition to data obtained from the Cadiz Allelopathy research group. The keywords used were Agave, spirostanic, furostanic, and saponin. RESULTS The shielding variations produced by functional groups on the aglycone core and the structural features of the most representative aglycones from Agave species are described. The effects are additive for up to four long-range connectivities. A method for the identification of aglycones (HMAI) is proposed to classify aglycones from Agave spp. through the use of 1 H-NMR and heteronuclear multiple bond correlation (HMBC) experiments. CONCLUSIONS The HMBC spectrum is representative of the structural features of aglycones from Agave spp. The HMBC method for aglycone identification (HMAI) method allowed the identification of pure saponins or mixtures thereof and this method can be used in combination with chromatographic techniques coupled with mass spectrometry to provide a more thorough analysis of Agave samples that contain aglycones.
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Affiliation(s)
- Ana M Simonet
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, Puerto Real, Cadiz, Spain
| | - Alexandra G Durán
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, Puerto Real, Cadiz, Spain
| | - Andy J Pérez
- Departamento de Análisis Instrumental, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Francisco A Macías
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, Puerto Real, Cadiz, Spain
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Abstract
NMR spectroscopy has become one of the preferred analytical techniques for metabolomics studies due to its inherent nondestructive nature, ability to identify and quantify metabolites simultaneously in a complex mixture, minimal sample preparation requirement, and high degree of experimental reproducibility. NMR-based metabolomics studies involve the measurement and multivariate statistical analysis of metabolites present in biological samples such as biofluids, stool/feces, intestinal content, tissue, and cell extracts by high-resolution NMR spectroscopy-the goal then is to identify and quantify metabolites and evaluate changes of metabolite concentrations in response to some perturbation. Here we describe methodologies for NMR sample preparation of biofluids (serum, saliva, and urine) and stool/feces, intestinal content, and tissues for NMR experiments including extraction of polar metabolites and application of NMR in metabolomics studies. One dimensional (1D) 1H NMR experiments with different variations such as pre-saturation, relaxation-edited, and diffusion-edited are routinely acquired for profiling and metabolite identification and quantification. 2D homonuclear 1H-1H TOCSY and COSY, 2D J-resolved, and heteronuclear 1H-13C HSQC and HMBC are also performed to assist with metabolite identification and quantification. The NMR data are then subjected to targeted and/or untargeted multivariate statistical analysis for biomarker discovery, clinical diagnosis, toxicological studies, molecular phenotyping, and functional genomics.
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Affiliation(s)
- Tapas K Mal
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA.
| | - Yuan Tian
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
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Nagy TM, Kövér KE, Sørensen OW. Double and adiabatic BANGO for concatenating two NMR experiments relying on the same pool of magnetization. J Magn Reson 2020; 316:106767. [PMID: 32540729 DOI: 10.1016/j.jmr.2020.106767] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/20/2020] [Accepted: 06/01/2020] [Indexed: 05/22/2023]
Abstract
It is shown how the same pool of magnetization can be tapped twice in two different concatenations of three experiments into a single pulse sequence with only one relaxation delay. This is accomplished by using the BANGO pulse sequence element twice for independent rotations of 1H magnetization attached or not attached to 13C and it includes a refinement of BANGO with an adiabatic 13C inversion pulse resulting in improved tolerance to a spread in 1JCH coupling constants that translates directly into improved sensitivity of the modular experiment relying on 1H magnetization attached to 13C. The two new pulse sequences are SEA XLOC-HMBC-H2OBC/2BOB and SEA XLOC(ZQ)-SEA XLOC(2Q)-H2OBC/2BOB which both represent a rapid route to complete heteronuclear one-bond and long-range JCH correlation maps for small molecules, as is demonstrated on ibuprofen and prednisolone.
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Affiliation(s)
- Tamás Milán Nagy
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Katalin E Kövér
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; MTA-DE Molecular Recognition and Interaction Research Group, University of Debrecen, Hungary.
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Sprengel J, Vetter W. NMR and GC/MS analysis of industrial chloroparaffin mixtures. Anal Bioanal Chem 2020; 412:4669-79. [PMID: 32468281 DOI: 10.1007/s00216-020-02720-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/12/2020] [Accepted: 05/15/2020] [Indexed: 11/02/2022]
Abstract
Chlorinated paraffins (CPs) are high-volume chemicals used worldwide in various industries as plasticizers, lubricants, and flame retardants. CPs are produced by chlorination of alkane mixtures which leads to complex products of thousands of homologs and congeners. Classic mass spectrometric analyses of CPs allow determining carbon chain lengths and degrees of chlorination while information on the substitution patterns cannot be derived. Therefore, we performed different one- and two-dimensional nuclear magnetic resonance spectroscopy (NMR) experiments, elemental analysis (EA), and gas chromatography coupled with electron capture negative ion mass spectrometry (GC/ECNI-MS) for the analysis of ten technical CP products with 42%, 52%, and 70% chlorine content from four producers. Slight differences in chlorine content but varying chain length compositions were observed for similarly labeled products from different manufacturers. Two-dimensional heteronuclear spectral quantum coherence (HSQC) measurements helped to evaluate ten structural elements in the products and confirmed the presence of geminal chlorine atoms in primary and secondary carbons in products with 70% chlorine. The variation of signal groups increased with increasing chlorine content of the products. Two-dimensional heteronuclear multiple bond coherence (HMBC) analysis of one sample and GC/ECNI-MS measurements indicated the presence of impurities (e.g., C9-CPs, iso-alkanes) in different technical CP products. These methods could in future allow for better distinction of CP mixtures, and an improved trace-back of environmental CPs to the source, based on specific structural features. Additionally, further structural characterization could help in the development of more accurate analysis processes. Graphical Abstract.
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Sharma D, Kumar V, Nautiyal R, Sharma P. Rheological and NMR spectral data sets of quaternary ammonium derivative of Cassia tora Linn. seed gum. Data Brief 2020; 29:105271. [PMID: 32123707 PMCID: PMC7038504 DOI: 10.1016/j.dib.2020.105271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/04/2022] Open
Abstract
The present study has been carried out to investigate the rheological and spectral data of galactomannan and its quaternary ammonium derivative obtained from the endosperm of Cassia tora Linn. seed. The characterization of native and quaternized Cassia tora gum (CTG) was done by employing 2D NMR spectroscopy including HSQC and HMBC spectra. The data was analysed to identify the quaternary ammonium moiety introduced onto the galactomannan chain. The correlation signal of carbon and hydrogen of quaternary ammonium groups introduced onto the galactomannan chain was observed at 56 and 2.7 ppm respectively in HSQC spectrum. Further, the rheological data of CTG and derivatized product has been discussed. The data is related to the research article “Synthesis and characterization of quaternized Cassia tora gum using Taguchi's L′16 approach” [1].
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Affiliation(s)
- Deepak Sharma
- Chemistry and Bioprospecting Division, Forest Research Institute, Indian Council of Forestry Research and Education, Dehradun-248006, India
| | - Vineet Kumar
- Chemistry and Bioprospecting Division, Forest Research Institute, Indian Council of Forestry Research and Education, Dehradun-248006, India
| | - Raman Nautiyal
- Division of Forestry Statistics, Indian Council of Forestry Research and Education, Dehradun-248006, India
| | - Pradeep Sharma
- Chemistry and Bioprospecting Division, Forest Research Institute, Indian Council of Forestry Research and Education, Dehradun-248006, India
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15
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Siemons L, Mackenzie HW, Shukla VK, Hansen DF. Intra-residue methyl-methyl correlations for valine and leucine residues in large proteins from a 3D- HMBC-HMQC experiment. J Biomol NMR 2019; 73:749-757. [PMID: 31720925 PMCID: PMC6875545 DOI: 10.1007/s10858-019-00287-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/03/2019] [Indexed: 05/21/2023]
Abstract
Methyl-TROSY based NMR experiments have over the last two decades become one of the most important means to characterise dynamics and functional mechanisms of large proteins and macromolecular machines in solution. The chemical shift assignment of methyl groups in large proteins is, however, still not trivial and it is typically performed using backbone-dependent experiments in a 'divide and conquer' approach, mutations, structure-based assignments or a combination of these. Structure-based assignment of methyl groups is an emerging strategy, which reduces the time and cost required as well as providing a method that is independent of a backbone assignment. One crucial step in available structure-based assignment protocols is linking the two prochiral methyl groups of leucine and valine residues. This has previously been achieved by recording NOESY spectra with short mixing times or by comparing NOESY spectra. Herein, we present a method based on through-bond scalar coupling transfers, a 3D-HMBC-HMQC experiment, to link the intra-residue methyl groups of leucine and valine. It is shown that the HMBC-HMQC method has several advantages over solely using NOESY spectra since a unique intra-residue cross-peak is observed. Moreover, overlap in the methyl-TROSY HMQC spectrum can easily be identified with the HMBC-HMQC experiment, thereby removing possible ambiguities in the assignment.
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Affiliation(s)
- Lucas Siemons
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, WC1E 6BT, UK
| | - Harold W Mackenzie
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, WC1E 6BT, UK
| | - Vaibhav Kumar Shukla
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, WC1E 6BT, UK.
| | - D Flemming Hansen
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, WC1E 6BT, UK.
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16
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Claridge TDW, Mayzel M, Kupče Ē. Triplet NOAH supersequences optimised for small molecule structure characterisation. Magn Reson Chem 2019; 57:946-952. [PMID: 31066946 DOI: 10.1002/mrc.4887] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 05/22/2023]
Abstract
A series of NMR supersequences are presented for the time-efficient structure characterisation of small molecules in the solution state. These triplet sequences provide HMBC, HSQC, and one homonuclear correlation experiment of choice according to the NMR by Ordered Acquisition using 1 H detection principle. The experiments are demonstrated to be compatible with non-uniform sampling schemes and may be acquired and processed under full automation.
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Affiliation(s)
- Tim D W Claridge
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | - Maksim Mayzel
- Application Science CH, MRS Division, Bruker BioSpin AG, Fällanden, Switzerland
| | - Ēriks Kupče
- Advanced Applications Development, Bruker UK Ltd., Coventry, UK
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17
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Kupče Ē, Claridge TDW. New NOAH modules for structure elucidation at natural isotopic abundance. J Magn Reson 2019; 307:106568. [PMID: 31421539 DOI: 10.1016/j.jmr.2019.106568] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 05/22/2023]
Abstract
We introduce several new NOAH modules designed for NMR supersequences that allow structure elucidation of small organic molecules from a single measurement. We show that double isotope filters (ZZ-filters) increase the flexibility of module permutation within the NMR supersequences, optimising combinations exploiting 15N and 13C nuclides. The time-shared 2BOB module combined with the ZZ-HMBC module (yielding NOAH-2 BO) provides an example of extending the NMR supersequences with parallel experiments (here 2BOB) that are incompatible with sequential implementation. Finally, the PANSY-COSY module combined with the HSQC sequence (yielding NOAH-2 SC2) provides an example of incorporating multiple receiver experiments into NMR supersequences opening new avenues for designing information rich NMR experiments. The new NOAH supersequences were utilized in computer assisted structure elucidation (CASE) study accomplished using the CMCse software.
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Affiliation(s)
- Ēriks Kupče
- Bruker UK Limited, Banner Lane, Coventry CV4 9GH, UK.
| | - Tim D W Claridge
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
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18
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Mandal R, Singh M, Krishnan AAV, Dahat YH, Bharitkar YP, Ravichandiran V, Hazra A. Semi-synthesis of a novel hybrid isoxazolidino withaferin via chemoselective and diastereoselective 1,3-dipolar nitrone cycloaddition reaction. Nat Prod Res 2019; 34:2208-2218. [PMID: 30938170 DOI: 10.1080/14786419.2019.1582045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A facile, atom-economic synthesis of isoxazilidino withaferin, a novel hybrid of withaferin A, has been accomplished via two-step reaction of nitrone synthesis followed by nitrone 1,3-dipolar cycloaddition. The reaction is highly chemoselective (preferential reaction only on one of the two double bonds present on withaferin A) and diastereoselective affording exclusively the cis-fused products. The structure was determined by detailed analysis of 1D, 2D NMR and mass spectral data.
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Affiliation(s)
- Ramkrishna Mandal
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Meenakshi Singh
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Amrutha A V Krishnan
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Yogita H Dahat
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Yogesh P Bharitkar
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - V Ravichandiran
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Abhijit Hazra
- National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
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19
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Bigler P, Furrer J. Why is HMBC superior to LR-HSQC? Influence of homonuclear couplings J HH' on the intensity of long-range correlations. Magn Reson Chem 2018; 56:1101-1116. [PMID: 29907970 DOI: 10.1002/mrc.4762] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/16/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Long-range heteronuclear single quantum correlation (LR-HSQC) experiments may be applied as an alternative to heteronuclear multiple-bond correlation (HMBC) experiments for detecting long-range correlations but has never enjoyed popularity for that purpose. To the best of our knowledge, the exact reasons have not yet been fully established. For both experiments, it is widely accepted that the evolution of proton-proton homonuclear couplings JHH' during the polarization transfer delays Δ leads to significant losses, and that the intensity of the observable coherence is zero when JHH' matches the condition Δ = 0.5/JHH' . Here, we analyze the influence of JHH' on the intensity of long-range correlations in HMBC and LR-HSQC spectra. We show that for both experiments long-range correlations will not be canceled because of homonuclear couplings JHH' . Our theoretical and experimental results definitely establish and validate the superiority of HMBC-based experiments among the family of heteronuclear long-range correlation experiments: (a) the overall cross peak's intensity is higher, and (b) in LR-HSQC experiments, the intensity of the long-range cross peaks is additionally influenced in an unwanted way by the magnitude and number of passive homonuclear proton-proton couplings JHH' .
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Affiliation(s)
- Peter Bigler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012, Bern, Switzerland
| | - Julien Furrer
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012, Bern, Switzerland
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20
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Görling B, Bermel W, Bräse S, Luy B. Homonuclear decoupling by projection reconstruction. Magn Reson Chem 2018; 56:1006-1020. [PMID: 30058249 DOI: 10.1002/mrc.4784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/16/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
Similar to J-resolved spectroscopy, also, heteronuclear multiple bond correlation (HMBC), heteronuclear single bond correlation (HSBC), and heteronuclear multiple quantum coherence (HMQC) types of correlation experiments result in homonuclear tilted multiplet patterns. On the example of the high-resolution heteronuclear single bond correlation (HR-HSBC) pulse sequence, it is shown how the tilt angle can be varied within a wide range of positive and negative values. Projection along the tilt angles in all cases results in homonuclear decoupling. Using well-known projection reconstruction techniques, the different tilt angles can be used to reconstruct a homonuclear decoupled two-dimensional correlation spectrum. The concept is proven and further refined by segmental projection reconstruction and the use of a clean in-phase heteronuclear single quantum correlation (CLIP-HSQC) spectrum with an effective zero tilt angle for further filtering. The proof of principle, its application to one-bond coupling measurement, as well as a basic HMBC, and a detailed discussion with comparison to other homodecoupling techniques are given.
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Affiliation(s)
- Benjamin Görling
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
- Bruker Biospin GmbH, Rheinstetten, Germany
| | | | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Burkhard Luy
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute for Biological Interfaces 4 - Magnetic Resonance, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
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21
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Silva Elipe MV, Donovan N, Krull R, Pooke D, Colson KL. Performance of new 400-MHz HTS power-driven magnet NMR technology on typical pharmaceutical API, cinacalcet HCl. Magn Reson Chem 2018; 56:817-825. [PMID: 29664140 DOI: 10.1002/mrc.4740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/26/2018] [Accepted: 04/02/2018] [Indexed: 06/08/2023]
Abstract
After years towards higher field strength magnets, nuclear magnetic resonance (NMR) technology in commercial instruments in the past decade has expanded at low and high magnetic fields to take advantage of new opportunities. At lower field strengths, permanent magnets are well established, whereas for midrange and high field, developments utilize superconducting magnets cooled with cryogenic liquids. Recently, the desire to locate NMR spectrometers in nontypical NMR laboratories has created interest in the development of cryogen-free magnets. These magnets require no cryogenic maintenance, eliminating routine filling and large cryogen dewars in the facility. Risks of spontaneous quenches and safety concerns when working with cryogenic liquids are eliminated. The highest field commercially available cryogen-free NMR magnet previously reported was at 4.7 T in 2013. Here we tested a prototype cryogen-free 9.4-T power-driven high-temperature-superconducting (HTS) magnet mated to commercial NMR spectrometer electronics. We chose cinacalcet HCl, a typical active pharmaceutical ingredient, to evaluate its performance towards structure elucidation. Satisfactory standard 1D and 2D homonuclear and heteronuclear NMR results were obtained and compared with those from a standard 9.4-T cryogenically cooled superconducting NMR instrument. The results were similar between both systems with minor differences. Further comparison with different shims and probes in the HTS magnet system confirmed that the magnet homogeneity profile could be matched with commercially available NMR equipment for optimal results. We conclude that HTS magnet technology works well providing results comparable with those of standard instruments, leading us to investigate additional applications for this magnet technology outside a traditional NMR facility.
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Affiliation(s)
- Maria Victoria Silva Elipe
- Department of Attribute Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA, 91320-1799, USA
| | - Neil Donovan
- Bruker BioSpin, 15 Fortune Drive, Billerica, MA, 01821, USA
| | - Robert Krull
- Bruker BioSpin, 15 Fortune Drive, Billerica, MA, 01821, USA
| | - Donald Pooke
- HTS-110, 1B Quadrant Drive, Lower Hutt, New Zealand
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22
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Caytan E, Ligny R, Carpentier JF, Guillaume SM. Evaluation of Band-Selective HSQC and HMBC: Methodological Validation on the Cyclosporin Cyclic Peptide and Application for Poly(3-hydroxyalkanoate)s Stereoregularity Determination. Polymers (Basel) 2018; 10:E533. [PMID: 30966567 PMCID: PMC6415406 DOI: 10.3390/polym10050533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/09/2018] [Accepted: 05/15/2018] [Indexed: 01/20/2023] Open
Abstract
Band-selective (bs) HSQC, improving spectral resolution by restriction of the heteronuclear dimension without inducing spectral folding, has been recently used for polymer tacticity determination. Herein is reported an evaluation of various bs-HSQC and bs-HMBC sequences, first from a methodological point of view (selectivity, dependence to INEPT interpulse delay or relaxation delay), using the cyclic peptide cyclosporin selected as a model compound, and then from an applicative approach, comparing tacticity determined from bs-HSQC and bs-HMBC experiments to the one obtained from 1D 13C{¹H} on poly(3-hydroxyalkanoate)s samples. For HSQC sequences, the 13C selectivity scheme consisting in substituting a 13C broadband refocalization by a selective one revealed itself problematic, with unwanted aliased signals, whereas the insertion of double pulsed field gradients spin-echo (DPFGSE) or the use of opposite sign gradients bracketing a selective refocalization gave satisfactory results. Determination of the probability of syndiotactic enchainments, Ps, by bs-HSQC is fully consistent and no precision loss was observed when decreasing acquisition time (37 min vs. 106 min for 1D 13C{¹H}). Bs-HMBC, although not straightforwardly applicable for tacticity determination, could provide (after a calibration step) an alternative for compounds of which only 13C carbonyl signals are resolved enough for discriminating between syndiotactic and isotactic configurations.
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Affiliation(s)
- Elsa Caytan
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes-UMR6226, F-35000 Rennes, France.
| | - Romain Ligny
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes-UMR6226, F-35000 Rennes, France.
| | | | - Sophie M Guillaume
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes-UMR6226, F-35000 Rennes, France.
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23
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Bigler P, Furrer J. Measurement of long-range heteronuclear coupling constants using the peak intensity in classical 1D HMBC spectra. Magn Reson Chem 2018; 56:329-337. [PMID: 29336081 DOI: 10.1002/mrc.4713] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 06/07/2023]
Abstract
In this contribution, we show that the magnitude of heteronuclear long-range coupling constants can be directly extracted from the classical 1D HMBC spectra, as all multiplet lines of a cross-peak always and exclusively vanish for the condition Δ = k/n JCH . To the best of our knowledge, this feature of the classical HMBC has not yet been noticed and exploited. This condition holds true, irrespective of the magnitude and numbers of additional active and passive homonuclear n JHH' couplings. Alternatively, the n JCH value may also be evaluated by fitting the peak's intensity in the individual spectra to its simple sin(πn JCH Δ)exp(-Δ/T2eff ) dependence. Compared to the previously proposed J-HMBC sequences that also use the variation of the cross-peak's intensity for extracting the coupling constants, the classical HMBC pulse sequence is significantly more sensitive.
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Affiliation(s)
- Peter Bigler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, Berne, CH-3012, Switzerland
| | - Julien Furrer
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, Berne, CH-3012, Switzerland
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24
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Hoeck C, Gotfredsen CH, Sørensen OW. S 3 HMBC hetero: Spin-State-Selective HMBC for accurate measurement of long-range heteronuclear coupling constants. J Magn Reson 2017; 275:68-72. [PMID: 28012298 DOI: 10.1016/j.jmr.2016.11.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
A novel method, Spin-State-Selective (S3) HMBC hetero, for accurate measurement of heteronuclear coupling constants is introduced. The method extends the S3 HMBC technique for measurement of homonuclear coupling constants by appending a pulse sequence element that interchanges the polarization in 13C-1H methine pairs. This amounts to converting the spin-state selectivity from 1H spin states to 13C spin states in the spectra of long-range coupled 1H spins, allowing convenient measurement of heteronuclear coupling constants similar to other S3 or E.COSY-type methods. As usual in this type of techniques, the accuracy of coupling constant measurement is independent of the size of the coupling constant of interest. The merits of the new method are demonstrated by application to vinyl acetate, the alkaloid strychnine, and the carbohydrate methyl β-maltoside.
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Affiliation(s)
- Casper Hoeck
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | | | - Ole W Sørensen
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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25
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Glanzer S, Kunert O, Zangger K. Determination of unresolved heteronuclear scalar coupling constants by J(up)-HSQMBC. J Magn Reson 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] [What about the content of this article? (0)] [Affiliation(s)] [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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26
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Keum SR, Lim HW. Novel stilbene-based Fischer base analog of leuco-TAM - (2E,2'Z)-{2-(4-(E)-styrylphenyl)propane-1,3-diylidene}bis(1,3,3-trimethylindoline) - derivatives: synthesis and structural consideration by 1D NMR and 2D NMR spectroscopy. Magn Reson Chem 2016; 54:143-150. [PMID: 26448377 DOI: 10.1002/mrc.4359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/21/2015] [Accepted: 08/28/2015] [Indexed: 06/05/2023]
Abstract
We report the synthesis of a series of novel stilbene-based (St) Fischer base analogs of leuco-triarylmethane (LTAM) dyes by treating Fischer base with (E)-4-styrylbenzaldehyde derivatives. All St-LTAM molecules examined herein are characterized by 1D and 2D NMR. They were found to exhibit ZE configuration and isomerize to their diastereomers EE and ZZ in 2-3 h. They exhibit type I behavior of diastereomeric isomerization.
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Affiliation(s)
- Sam-Rok Keum
- Department of Advanced Materials Chemistry, Korea University, Se-Jong, 339-700, Korea
| | - Hyun-Woo Lim
- Department of Advanced Materials Chemistry, Korea University, Se-Jong, 339-700, Korea
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27
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Kjaerulff L, Benie AJ, Hoeck C, Gotfredsen CH, Sørensen OW. S(3) HMBC: Spin-State-Selective HMBC for accurate measurement of homonuclear coupling constants. Application to strychnine yielding thirteen hitherto unreported J(HH). J Magn Reson 2016; 263:101-107. [PMID: 26774647 DOI: 10.1016/j.jmr.2015.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 11/23/2015] [Accepted: 11/30/2015] [Indexed: 06/05/2023]
Abstract
A novel method, Spin-State-Selective (S(3)) HMBC, for accurate measurement of homonuclear coupling constants is introduced. As characteristic for S(3) techniques, S(3) HMBC yields independent subspectra corresponding to particular passive spin states and thus allows determination of coupling constants between detected spins and homonuclear coupling partners along with relative signs. In the presented S(3) HMBC experiment, spin-state selection occurs via large one-bond coupling constants ensuring high editing accuracy and unequivocal sign determination of the homonuclear long-range relative to the associated one-bond coupling constant. The sensitivity of the new experiment is comparable to that of regular edited HMBC and the accuracy of the J/RDC measurement is as usual for E.COSY and S(3)-type experiments independent of the size of the homonuclear coupling constant of interest. The merits of the method are demonstrated by an application to strychnine where thirteen J(HH) coupling constants not previously reported could be measured.
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Affiliation(s)
- Louise Kjaerulff
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Andrew J Benie
- Department of Peptide & Protein Biophysics, Novo Nordisk, 2760 Måløv, Denmark
| | - Casper Hoeck
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | | | - Ole W Sørensen
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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28
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Balaban AT, Young DC, Plavec J, Pečnik K, Pompe M, Dahl JE, Carlson RMK. NMR spectral properties of the tetramantanes - nanometer-sized diamondoids. Magn Reson Chem 2015; 53:1003-1018. [PMID: 26286373 DOI: 10.1002/mrc.4289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/08/2015] [Accepted: 06/12/2015] [Indexed: 06/04/2023]
Abstract
Tetramantanes, and all diamondoid hydrocarbons, possess carbon frameworks that are superimposable upon the cubic diamond lattice. This characteristic is invaluable in assigning their (1)H and (13)C NMR spectra because it translates into repeating structural features, such as diamond-cage isobutyl moieties with distinctively complex methine to methylene signatures in COSY and HMBC data, connected to variable, but systematic linkages of methine and quaternary carbons. In all tetramantane C22H28 isomers, diamond-lattice structures result in long-range (4)JHH, W-coupling in COSY data, except where negated by symmetry; there are two highly symmetrical and one chiral tetramantane (showing seven (4)JHH). Isobutyl-cage methines of lower diamondoids and tetramantanes are the most shielded resonances in their (13)C spectra (<29.5 ppm). The isobutyl methylenes are bonded to additional methines and at least one quaternary carbon in the tetramantanes. W-couplings between these methines and methylenes clarify spin-network interconnections and detailed surface hydrogen stereochemistry. Vicinal couplings of the isobutyl methylenes reveal positions of the quaternary carbons: HMBC data then tie the more remote spin systems together. Diamondoid (13) C NMR chemical shifts are largely determined by α and β effects, however γ-shielding effects are important in [123]tetramantane. (1)H NMR chemical shifts generally correlate with numbers of 1,3-diaxial H-H interactions. Tight van der Waals contacts within [123]tetramantane's molecular groove, however, form improper hydrogen bonds, deshielding hydrogen nuclei inside the groove, while shielding those outside, indicated by Δδ of 1.47 ppm for geminal hydrogens bonded to C-3,21. These findings should be valuable in future NMR studies of diamondoids/nanodiamonds of increasing size.
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Affiliation(s)
- Alexandru T Balaban
- Texas A&M University at Galveston, Department of Marine Sciences, 200 Seawolf Parkway, Galveston, TX, 77553, USA
| | | | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Klemen Pečnik
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Matevž Pompe
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Aškerčeva 5, 1000, Ljubljana, Slovenia
| | - Jeremy E Dahl
- Stanford Institute for Materials and Energy Sciences, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Robert M K Carlson
- Stanford Institute for Materials and Energy Sciences, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
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Ayer SK, Kimball EA, Olvera A, Djieutedjeu H, Fotie J, Poudeu PFP. (1) H and (13) C NMR assignments for a series of Diels-Alder adducts of anthracene and 9-substituted anthracenes. Magn Reson Chem 2015; 53:551-555. [PMID: 26018118 DOI: 10.1002/mrc.4268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/28/2015] [Accepted: 05/01/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Suraj K Ayer
- Department of Chemistry and Physics, Southeastern Louisiana University, SLU 10878, Hammond, LA, 70402-0878, USA
| | - Elizabeth A Kimball
- Department of Chemistry and Physics, Southeastern Louisiana University, SLU 10878, Hammond, LA, 70402-0878, USA
| | - Alan Olvera
- Department of Materials Science and Engineering, University of Michigan at Ann Arbor, 2300 Hayward Street, Ann Arbor, MI, 48109-2136, USA
| | - Honore Djieutedjeu
- Department of Materials Science and Engineering, University of Michigan at Ann Arbor, 2300 Hayward Street, Ann Arbor, MI, 48109-2136, USA
| | - Jean Fotie
- Department of Chemistry and Physics, Southeastern Louisiana University, SLU 10878, Hammond, LA, 70402-0878, USA
| | - Pierre F P Poudeu
- Department of Materials Science and Engineering, University of Michigan at Ann Arbor, 2300 Hayward Street, Ann Arbor, MI, 48109-2136, USA
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Cheatham S, Kline M, Kupče E. Exploiting natural abundance 13C-15N coupling as a method for identification of nitrogen heterocycles: practical use of the HCNMBC sequence. Magn Reson Chem 2015; 53:363-368. [PMID: 25594305 DOI: 10.1002/mrc.4205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/09/2014] [Accepted: 12/12/2014] [Indexed: 06/04/2023]
Abstract
In this paper, we detail the results of (1)H-(15)N correlation data obtained via (13)C-(15)N coupling at natural abundance on a number of classes of azoles including pyrazoles, imidazoles and triazoles. The experiment produces data that is highly complementary to direct (1)H-(15)N HMBC type correlations in that it can provide (15)N chemical shift data for nitrogen that may not show up in the HMBC. This is particularly advantageous in the triazoles where (15)N chemical shift can be diagnostic of regiochemistry. Because of the consistency in JCN values among the azoles, the experiment produces distinctive correlation patterns that can be used for identification of regiochemistry. The experiment can also be used to directly measure (13)C-(15)N coupling constants.
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Cheatham S, Gierth P, Bermel W, Kupče Ē. HCNMBC--a pulse sequence for H-(C)-N Multiple Bond Correlations at natural isotopic abundance. J Magn Reson 2014; 247:38-41. [PMID: 25233112 DOI: 10.1016/j.jmr.2014.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/23/2014] [Accepted: 07/25/2014] [Indexed: 06/03/2023]
Abstract
We propose a pulse sequence, HCNMBC for multiple-bond H-(C)-N correlation experiments via one-bond (1)J(C,H) and one- or multiple bond (n)J(N,C) coupling constants (typically n=1-3) at the natural isotopic abundance. A new adiabatic refocussing sequence is introduced to provide accurate and robust refocussing of both chemical shift and J-evolution over wide ranges of C-13 and N-15 frequencies. It is demonstrated that the proposed pulse sequence provides high quality spectra even for sub-milligram samples. We show that when a 1.7 mm cryoprobe is available as little as 10 μg of glycine in D2O is sufficient to obtain the HCNMBC spectrum in ca. 12 h. The preliminary results indicate that the pulse sequence has a great potential in the structure determination of nitrogen heterocycles especially in cases where synthesis produces regioisomers.
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Affiliation(s)
- Steve Cheatham
- DuPont Crop Protection, Stine-Haskell Research Center, Newark, DE 19714, USA
| | - Peter Gierth
- Bruker UK Limited, Banner Lane, Coventry CV4 9GH, UK
| | | | - Ēriks Kupče
- Bruker UK Limited, Banner Lane, Coventry CV4 9GH, UK.
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Donovan KJ. Synchronized and concurrent experiments in Moving Tube NMR: using separate sample volumes for different pulse sequences. J Magn Reson 2014; 247:104-109. [PMID: 25261744 DOI: 10.1016/j.jmr.2014.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/27/2014] [Accepted: 08/30/2014] [Indexed: 06/03/2023]
Abstract
This study presents a new application of sample shuttling with a long NMR tube (Moving Tube NMR, MT-NMR) as a method for collecting different experiments synchronously or even concurrently using separate sample regions. Synchronized experiments were performed using an automated shuttling apparatus to move different sample regions into the coil between transients such that each experiment was collected using a separate, specific sample segment. Additionally, a 2D NOESY spectrum and a double quantum filtered COSY (DQCOSY) spectrum were collected concurrently by shuttling between two different sample regions during the NOESY mixing time. These applications of the Moving Tube technique show that it is a useful platform for compounded data acquisition to optimize spectrometer time by minimizing measurement times and avoiding problems arising from instrument and sample instabilities. Furthermore, collecting a DQCOSY during a 2D NOESY mixing time opens a wide array of possibilities, as this principle can be applied to collect any experiment during a NOESY mixing time provided that the mixing period is longer than the sum of the sample shuttling time plus a complete scan of the intermittent experiment. While this methodology relies on the use of a long sample tube, it does not require excessive sample volumes, as two milliliters is enough to constitute multiple sample regions.
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Affiliation(s)
- Kevin J Donovan
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA.
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Marchione AA, Dooley RJ, Conklin B. Comparison of 1H-19F two-dimensional NMR scalar coupling correlation pulse sequences. Magn Reson Chem 2014; 52:183-189. [PMID: 24535754 DOI: 10.1002/mrc.4052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/06/2014] [Accepted: 01/18/2014] [Indexed: 06/03/2023]
Abstract
The effectiveness of hetero-COSY, HETCOR, HMQC, and HSQC two-dimensional NMR pulse sequences for detection of (19)F-(1)H correlations by scalar coupling was evaluated on monofluorinated and polyfluorinated test compounds. All four of these sequences were effective in observing (1)H-(19)F correlations, using either (19) F or (1)H as the observe nucleus. All four sequences were amenable, to some degree, to adjustment to observe larger or smaller couplings preferentially. A 1/2J echo filter was effectively applied to remove artifacts from (2)JFF strong coupling. The HETCOR experiments afforded the best overall combination of sensitivity, resolution and selectivity for JHF.
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Yao CM, Yang XW. Bioactivity-guided isolation of polyacetylenes with inhibitory activity against NO production in LPS-activated RAW264.7 macrophages from the rhizomes of Atractylodes macrocephala. J Ethnopharmacol 2014; 151:791-799. [PMID: 24296088 DOI: 10.1016/j.jep.2013.10.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 08/25/2013] [Accepted: 10/02/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The rhizome of Atractylodes macrocephala (Compositae) is one of the most well-known traditional Chinese medicine in China, Japan and Korea, which has a long history of use for the treatment of splenic asthenia, edema, anorexia, and excessive perspiration, etc. As active compounds of anti-inflammatory activity of this medicinal plant have not been fully elucidated, the aim of this study was to isolate and identify the active constituents inhibiting nitric oxide (NO) production from the rhizomes of A. macrocephala. MATERIALS AND METHODS Inhibitory activity against NO production in lipopolysaccharide-activated RAW264.7 macrophages was evaluated by Griess reaction. Fifteen polyacetylenes were isolated from the active ethyl acetate extract using activity-guided screening. The structures of all compounds were elucidated by spectroscopic methods and comparison with published data. The compounds were further tested for their inhibitory activity against NO production. RESULTS Seven new polyacetylenes, named atractylodemaynes A-G (1-7), along with eight known ones (8-15) were isolated. Compound 14 was isolated for the first time from the rhizomes of A. macrocephala. The study showed that the tested compounds exhibited inhibitory activity against NO production in a dose-dependent manner. Among them, compounds 10, 11 and 12 had relatively stronger inhibitory effect with IC50 values of 28, 23 and 19μM, respectively. CONCLUSION The results demonstrated that the polyacetylenes might greatly contribute to the anti-inflammatory activity of the rhizomes of A. macrocephala.
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Key Words
- (1)H–(1)H COSY
- (1)H–(1)H correlated spectroscopy
- 14-Acetoxy-12-senecioyloxytetradeca-2E,8E,10E-trien-4,6-diyn-1-ol (PubChem CID: 14448076)
- 14-Acetoxy-12-α-methylbutyryltetradeca-2E,8E,10E-trien-4,6-diyne-1-ol (PubChem CID: 5319529)
- 14-Acetoxy-12-α-methylbutyryltetradeca-2E,8Z,10E-trien-4,6-diyne-1-ol (PubChem CID: 5319530)
- 14-Acetoxy-12-β-methylbutyryltetradeca-2E,8E,10E-trien-4,6-diyne-1-ol (PubChem CID: 14586258)
- 14-α-Methylbutyryltetradeca-2E,8E,10E-trien-4,6-diyne-1-ol (PubChem CID: 5319531)
- 14-β-Methylbutyryltetradeca-2E,8E,10E-trien-4,6-diyne-1-ol (PubChem CID: 11544212)
- 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide
- AMR
- AO-I
- AO-III
- Anti-inflammatory
- Atractylodes macrocephala
- Atractylodis Macrocephalae Rhizoma
- BuOH
- CC
- CHX
- Compositae
- EtOAc
- EtOH
- HMBC
- HPLC
- HRESIMS
- HSQC
- IND
- L-N(6)-(1-iminoethyl)-lysine
- L-NIL
- LPS
- MTT
- NMR
- NO
- Nitric oxide
- Polyacetylenes
- atractylenolide I
- atractylenolide III
- column chromatography
- cyclohexane
- ethanol
- ethyl acetate
- heteronuclear multiple bond correlation
- heteronuclear single quantum correlation
- high-performance liquid chromatography
- high-resolution electric spray ion mass spectrum
- indomethacin
- lipopolysaccharides
- n-butanol
- nitric oxide
- nuclear magnetic resonance
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Affiliation(s)
- Chun-Mei Yao
- State Key Laboratory of Natural and Biomimetic Drugs (Peking University), Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, Beijing 100191, China
| | - Xiu-Wei Yang
- State Key Laboratory of Natural and Biomimetic Drugs (Peking University), Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, Beijing 100191, China.
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Ivanova B, Spiteller M. UV-MALDI mass spectrometric quantitation of uracil based pesticides in fruit soft drinks along with matrix effects evaluation. Ecotoxicol Environ Saf 2014; 100:233-241. [PMID: 24018142 DOI: 10.1016/j.ecoenv.2013.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 06/02/2023]
Abstract
This study focused on the development of the accurate and precise quantitative method for the determination of pesticides bromacil (1), terbacil (2), lenacil (3), butafenacil (4) and flupropacil (5) in fruit based soft drinks. Three different types of drinks are bought from market; huddled orange fruit drink (100%) (I), red-oranges (II) and multivitamin drink containing strawberry, orange, banana and maracuja (III). Samples were analyzed "with" and "without" pulp utilizing LC-ESI (or APCI) MS/MS, HPLC-ESI-(or APCI)-MS/MS and UV-MALDI-Orbitrap-MS methods. The effect of high complexity of the food matrix on the analysis was discussed. Study focuses on the advantages of the UV-MALDI-Orbitrap-MS method compared to the traditionally involved GC alone or hybrid methods such as GC-MS and LC-MS/MS for quantification of pesticides in water and soft drinks. The developed method included the techniques performed for validation, calibration and standardization. The target pesticides are widely used for the treatment of citrus fruits and pineapples, but for soft drink products, there are still no clear regulations on pesticide residues limits. The matrix effects in the analysis of fruit drinks required implementation of the exact standard reference material corresponds to the variety of food matrices. This paper contributed to the broad analytical implementation of the UV-MALDI-Orbitrap-MS method in the quality control and assessment programs for monitoring of pesticide contamination in fruit based sodas.
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Affiliation(s)
- Bojidarka Ivanova
- Lehrstuhl für Analytische Chemie, Institut für Umweltforschung, Fakultät für Chemie, Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Nordrhein-Westfalen, Germany.
| | - Michael Spiteller
- Lehrstuhl für Analytische Chemie, Institut für Umweltforschung, Fakultät für Chemie, Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Nordrhein-Westfalen, Germany
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Satoh Née Okihara R, Saito T, Ogata H, Ohsaki A, Iida T, Asahina K, Mitamura K, Ikegawa S, Hofmann AF, Hagey LR. N-Methyltaurine N-acyl amidated bile acids and deoxycholic acid in the bile of angelfish (Pomacanthidae): a novel bile acid profile in Perciform fish. Steroids 2014; 80:15-23. [PMID: 24291417 DOI: 10.1016/j.steroids.2013.11.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/13/2013] [Accepted: 11/20/2013] [Indexed: 01/30/2023]
Abstract
Two novel N-acyl amidated bile acids, N-methyltaurine conjugated cholic acid and N-methyltaurine conjugated deoxycholic acid, were found to be major biliary bile acids in two species of angelfish the regal (Pygoplites diacanthus) and the blue-girdled (Pomacanthus navarchus) angelfish. The identification was based on their having MS and NMR spectra identical to those of synthetic standards. A survey of biliary bile acids of 10 additional species of angelfish found 7 with N-methyltaurine conjugation. In all 12 species, conjugated deoxycholic acid (known to be formed by bacterial 7-dehydroxylation of cholic acid) was a major bile acid. In all previous studies of biliary bile acids in fish, deoxycholic acid has been present in only trace proportions. In addition, bile acid conjugation with N-methyltaurine has not been detected previously in any known vertebrate. N-methyltaurine conjugated bile acids are resistant to bacterial deconjugation and dehydroxylation, and such resistance to bacterial enzymes should aid in the maintenance of high concentrations of bile acids during lipid digestion. Our findings suggest that these species of angelfish have a novel microbiome in their intestine containing anaerobic bacteria, and describe the presence of N-methyltaurine conjugated bile acids that are resistant to bacterial attack.
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Affiliation(s)
- Rika Satoh Née Okihara
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan
| | - Tetsuya Saito
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan
| | - Hiroaki Ogata
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan
| | - Ayumi Ohsaki
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan
| | - Takashi Iida
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
| | - Kiyoshi Asahina
- Department of Marine Science and Resource, College of Bioresource Sciences, Nihon University, Kameino, Fujisawa, Kanagawa 274-8555, Japan
| | - Kuniko Mitamura
- Faculty of Pharmaceutical Sciences, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan
| | - Shigeo Ikegawa
- Faculty of Pharmaceutical Sciences, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan
| | - Alan F Hofmann
- Department of Medicine, University of California, La Jolla, San Diego, CA 92093-0063, USA
| | - Lee R Hagey
- Department of Medicine, University of California, La Jolla, San Diego, CA 92093-0063, USA.
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Rocha DHA, Pinto DCGA, Seixas RSGR, Silva AMS. 3-Methylflavones characterization revisited: complete assignment of 1H and 13C NMR data. Magn Reson Chem 2014; 52:47-50. [PMID: 24214312 DOI: 10.1002/mrc.4026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/06/2013] [Accepted: 10/08/2013] [Indexed: 06/02/2023]
Abstract
Ten 3-methylflavone derivatives were studied. Previously reported NMR data of some derivatives were corrected and/or completed, including the complete assignment of the two known natural derivatives. The complete (1)H and (13)C NMR assignments were achieved by combination of one-dimensional and two-dimensional NMR experiments.
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Affiliation(s)
- Djenisa H A Rocha
- Department of Chemistry and QOPNA, University of Aveiro, Aveiro, Portugal
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Al Chab F, Fenet B, Le Borgne M, Jose J, Pinaud N, Guillon J, Ettouati L. 1H and 13C NMR assignments of bioactive indeno[1,2-b]indole-10-one derivatives. Magn Reson Chem 2013; 51:837-841. [PMID: 24123338 DOI: 10.1002/mrc.4016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 06/02/2023]
Abstract
The complete (1)H and (13)C assignments of eight bioactive indeno[1,2-b]indole-10-one derivatives were accomplished by the combined use of one-dimensional and two-dimensional NMR experiments.
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Affiliation(s)
- Faten Al Chab
- Université Lyon 1, Faculté de Pharmacie - ISPB, EA 4446 Biomolécules Cancer et Chimiorésistances, SFR Santé Lyon-Est CNRS UMS3453 - INSERM US7, Université de Lyon, 8 avenue Rockefeller, F-69373, Lyon, France
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Kim KH, Moon E, Kim SY, Choi SU, Lee JH, Lee KR. 4-Methylthio-butanyl derivatives from the seeds of Raphanus sativus and their biological evaluation on anti-inflammatory and antitumor activities. J Ethnopharmacol 2013; 151:503-508. [PMID: 24231071 DOI: 10.1016/j.jep.2013.11.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/28/2013] [Accepted: 11/04/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Raphanus sativus seeds (Brassicaceae) known as Raphani Semen have long been used as anti-cancer and/or anti-inflammatory agents in Korean traditional medicine. This study was designed to isolate the bioactive constituents from the seed extracts of Raphanus sativus and evaluate their anti-inflammatory and antitumor activities. MATERIAL AND METHODS Bioassay-guided fractionation and chemical investigation of a methanolic extract of the seeds of Raphanus sativus led to the isolation and identification of seven 4-methylthio-butanyl derivatives. Structural elucidation of the isolated compounds was carried out using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy techniques ((1)H, (13)C, COSY, HMQC and HMBC experiments) and mass spectrometry. RESULTS The isolated compounds were characterized as in the following: three new 4-methylthio-butanyl derivatives, sinapoyl desulfoglucoraphenin (1), (E)-5-(methylsulfinyl)pent-4-enoxylimidic acid methyl ester (2), and (S)-5-((methylsulfinyl)methyl)pyrrolidine-2-thione (3), together with four known compounds, 5-(methylsulfinyl)-4-pentenenitrile (4), 5-(methylsulfinyl)-pentanenitrile (5), sulforaphene (6), and sulforaphane (7). Full NMR data assignments of the three known compounds 4-6 were also reported for the first time. We evaluated the anti-neuroinflammatory effect of 1-7 in lipopolysaccharide-stimulated murine microglia BV2 cells. Compound 1 significantly inhibited nitrite oxide production with IC50 values of 45.36 μM. Moreover, it also reduced the protein expression of inducible nitric oxide synthase. All isolates were also evaluated for their antiproliferative activities against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15), and all of them showed antiproliferative activity against the HCT-15 cell, with IC50 values of 8.49-23.97 μM. CONCLUSIONS 4-Methylthio-butanyl derivatives were one of the main compositions of Raphanus sativus seeds, and activities demonstrated by the isolated compounds support the ethnopharmacological use of Raphanus sativus seeds (Brassicaceae) as anti-cancer and/or anti-inflammatory agents.
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Affiliation(s)
- Ki Hyun Kim
- Natural Products Laboratory, School of Pharmacy, Sungkyunkwan University, 300 Chonchon-dong, Jangan-ku, Suwon, Gyeonggi-do 440-746, Republic of Korea
| | - Eunjung Moon
- College of Pharmacy, Gachon University, #191 Hambakmoero, Yeonsu-gu, Incheon 406-799, Republic of Korea
| | - Sun Yeou Kim
- College of Pharmacy, Gachon University, #191 Hambakmoero, Yeonsu-gu, Incheon 406-799, Republic of Korea; Gachon Medical Research Institute, Gil Medical Center, Inchon 405-760, Republic of Korea
| | - Sang Un Choi
- Korea Research Institute of Chemical Technology, Teajeon 305-600, Republic of Korea
| | - Jei Hyun Lee
- College of Oriental Medicine, Dongguk University, Gyeong Ju 780-714, Republic of Korea
| | - Kang Ro Lee
- Natural Products Laboratory, School of Pharmacy, Sungkyunkwan University, 300 Chonchon-dong, Jangan-ku, Suwon, Gyeonggi-do 440-746, Republic of Korea.
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Saurí J, Parella T. On the interference of J(HH) modulation in HSQMBC-IPAP and HMBC-IPAP experiments. Magn Reson Chem 2013; 51:509-516. [PMID: 23780917 DOI: 10.1002/mrc.3977] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/22/2013] [Accepted: 05/19/2013] [Indexed: 06/02/2023]
Abstract
The effects of phase modulation due to homonuclear proton-proton coupling constants in HSQMBC-IPAP and HMBC-IPAP experiments are experimentally evaluated. We show that accurate values of small proton-carbon coupling constants, (n)J(CH), can be extracted even for phase-distorted cross-peaks obtained from a selHSQMBC experiment applied simultaneously on two mutually J-coupled protons. On the other hand, an assessment of the reliability of (n)J(CH) measurement from distorted cross-peaks obtained in broadband IPAP versions of equivalent HMBC and HSQMBC experiments is also presented. Finally, we show that HMBC-COSY experiments could be an excellent complement to HMBC for the measurement of small (n)J(CH) values.
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Affiliation(s)
- Josep Saurí
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Catalonia, Spain
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Michl J, Jennings HM, Kite GC, Ingrouille MJ, Simmonds MSJ, Heinrich M. Is aristolochic acid nephropathy a widespread problem in developing countries? A case study of Aristolochia indica L. in Bangladesh using an ethnobotanical-phytochemical approach. J Ethnopharmacol 2013; 149:235-44. [PMID: 23806867 DOI: 10.1016/j.jep.2013.06.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 05/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Species of Aristolochia are associated with aristolochic acid nephropathy (AAN), a renal interstitial fibrosis and upper urinary tract cancer (UUC). Aristolochic acid nephropathy has been reported in ten countries but its true incidence is unknown and most likely underestimated. By combining an ethnobotanical and phytochemical approach we provide evidence for the risk of AAN occurring in Bangladesh. More specifically, we assess the intra-specific variation of aristolochic acid analogues in medicinally used Aristolochia indica samples from Bangladesh. MATERIALS AND METHODS Ethnobotanical information was collected from 16 kavirajes (traditional healers) in different study locations in Bangladesh. Plant samples were obtained from native habitats, botanical gardens, herbal markets and pharmaceutical companies. The samples were extracted using 70% methanol and were analysed using LC-DAD-MS and (1)H-NMR. RESULTS Roots as well as leaves are commonly used for symptoms such as snake bites and sexual problems. Among the informants knowledge about toxicity or side effects is very limited and Aristolochia indica is often administered in very high doses. Replacement of Aristolochia indica with other medicinal plants such as Rauvolfia serpentina (L.) Benth. ex Kurz was common. Aristolochia indica samples contained a variety of aristolochic acid analogues such as aristolochic acid I, aristolochic acid II, cepharadione A and related compounds. CONCLUSIONS AAN cases are likely to occur in Bangladesh and more awareness needs to be raised about the health risks associated with the use of Aristolochia indica and other species of Aristolochia as herbal medicines.
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Affiliation(s)
- Johanna Michl
- Centre for Pharmacognosy and Phytotherapy, UCL School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
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Siddiqui NN, Aman A, Silipo A, Qader SAU, Molinaro A. Structural analysis and characterization of dextran produced by wild and mutant strains of Leuconostoc mesenteroides. Carbohydr Polym 2013; 99:331-8. [PMID: 24274515 DOI: 10.1016/j.carbpol.2013.08.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/30/2013] [Accepted: 08/01/2013] [Indexed: 11/18/2022]
Abstract
An exopolysaccharide known as dextran was produced by Leuconostoc mesenteroides KIBGE-IB22 (wild) and L. mesenteroides KIBGE-IB22M20 (mutant). The structure was characterized using FTIR, (1)H NMR, (13)C NMR and 2D NMR spectroscopic techniques, whereas surface morphology was analyzed using SEM. A clear difference in the spectral chemical shift patterns was observed in both samples. All the spectral data indicated that the exopolysaccharide produced by KIBGE-IB22 is a mixture of two biopolymers. One was dextran in α-(1 → 6) configuration with a small proportion of α-(1 → 3) branching and the other was levan containing β-(2 → 6) fructan fructofuranosyl linkages. However, remarkably the mutant only produced dextran without any concomitant production of levan. Study suggested that the property of KIBGE-IB22M20, regarding improved production of high molecular weight dextran in a shorter period of fermentation time without any contamination of other exopolysaccharide, could be employed to make the downstream process more feasible and cost effective on large scale.
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Affiliation(s)
- Nadir Naveed Siddiqui
- The Karachi Institute of Biotechnology & Genetic Engineering (KIBGE), University of Karachi, Karachi 75270, Pakistan
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Parella T, Espinosa JF. Long-range proton-carbon coupling constants: NMR methods and applications. Prog Nucl Magn Reson Spectrosc 2013; 73:17-55. [PMID: 23962883 DOI: 10.1016/j.pnmrs.2013.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 07/03/2013] [Accepted: 07/03/2013] [Indexed: 06/02/2023]
Abstract
A general review of novel NMR methods to measure heteronuclear long-range proton-carbon coupling constants ((n)JCH; n>1) in small molecules is made. NMR experiments are classified in terms of NMR pulse scheme and cross-peak nature. A discussion about simplicity, general applicability and accuracy for each particular NMR experiment is presented and exemplified. Important aspects such as the sign determination and measurement of very small coupling values involving protonated and non-protonated carbons as well as the complementarity between different experiments are also discussed. Finally, a compilation of applications in structural and conformational analysis of different types of molecules since 2000 is surveyed.
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Affiliation(s)
- Teodor Parella
- Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Kaszowska M, Jachymek W, Niedziela T, Koj S, Kenne L, Lugowski C. The novel structure of the core oligosaccharide backbone of the lipopolysaccharide from the Plesiomonas shigelloides strain CNCTC 80/89 (serotype O13). Carbohydr Res 2013; 380:45-50. [PMID: 23920477 DOI: 10.1016/j.carres.2013.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 07/05/2013] [Accepted: 07/12/2013] [Indexed: 11/26/2022]
Abstract
The new structure of the core oligosaccharide of Plesiomonas shigelloides CNCTC 80/89 (serotype O13) lipopolysaccharide has been investigated by chemical methods, (1)H and (13)C NMR spectroscopy and matrix-assisted laser-desorption/ionization time of flight (MALDI-TOF). It was concluded that the core oligosaccharide of P. shigelloides CNCTC 80/89 is a nonasaccharide with the following structure: The position of glycine was determined by MALDI-TOF MS/MS analyses.
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Affiliation(s)
- Marta Kaszowska
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, PL-53-114 Wroclaw, Poland.
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Patel DN, Li L, Kee CL, Ge X, Low MY, Koh HL. Screening of synthetic PDE-5 inhibitors and their analogues as adulterants: analytical techniques and challenges. J Pharm Biomed Anal 2013; 87:176-90. [PMID: 23721687 DOI: 10.1016/j.jpba.2013.04.037] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 10/26/2022]
Abstract
The popularity of phosphodiesterase type 5 (PDE-5) enzyme inhibitors for the treatment of erectile dysfunction has led to the increase in prevalence of illicit sexual performance enhancement products. PDE-5 inhibitors, namely sildenafil, tadalafil and vardenafil, and their unapproved designer analogues are being increasingly used as adulterants in the herbal products and health supplements marketed for sexual performance enhancement. To date, more than 50 unapproved analogues of prescription PDE-5 inhibitors were found as adulterants in the literature. To avoid detection of such adulteration by standard screening protocols, the perpetrators of such illegal products are investing time and resources to synthesize exotic analogues and devise novel means for adulteration. A comprehensive review of conventional and advance analytical techniques to detect and characterize the adulterants is presented. The rapid identification and structural elucidation of unknown analogues as adulterants is greatly enhanced by the wide myriad of analytical techniques employed, including high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), liquid chromatography mass-spectrometry (LC-MS), nuclear magnetic resonance (NMR) spectroscopy, vibrational spectroscopy, liquid chromatography-Fourier transform ion cyclotron resonance-mass spectrometry (LC-FT-ICR-MS), liquid chromatograph-hybrid triple quadrupole linear ion trap mass spectrometer with information dependent acquisition, ultra high performance liquid chromatography-time of flight-mass spectrometry (UHPLC-TOF-MS), ion mobility spectroscopy (IMS) and immunoassay methods. The many challenges in detecting and characterizing such adulterants, and the need for concerted effort to curb adulteration in order to safe guard public safety and interest are discussed.
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Affiliation(s)
- Dhavalkumar Narendrabhai Patel
- Department of Pharmacy, Faculty of Science, National University of Singapore, 18 Science Drive 4, Singapore 117543, Singapore
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Perry MB, MacLean LL, Gottschalk M, Aragon V, Vinogradov E. Structure of the capsular polysaccharides and lipopolysaccharides from Haemophilus parasuis strains ER-6P (serovar 15) and Nagasaki (serovar 5). Carbohydr Res 2013; 378:91-7. [PMID: 23664728 DOI: 10.1016/j.carres.2013.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 04/09/2013] [Accepted: 04/10/2013] [Indexed: 11/25/2022]
Abstract
Haemophilus parasuis is a Gram-negative bacterium from the family Pasteurellaceae and a swine pathogen. H. parasuis is found in the upper respiratory tract of piglets and produces Glässer's disease, an invasive disease characterized by polyserositis. H. parasuis contains a short lipopolysaccharide (LPS) or lipooligosaccharide (LOS) reported to play a partial role in interaction with host cells. The presence of capsule has been phenotypically demonstrated in certain H. parasuis strains and its role in virulence has been suggested, but the chemical structure of the surface polysaccharides of this bacterium was unknown. The structure of capsular polysaccharide (CPS) and LOS from virulent strains ER-6P and Nagasaki was studied by NMR spectroscopy, mass spectrometry and chemical methods. CPS from both strains had the same main chain with disaccharide repeating unit, substituted with α-Neu5R-(2-3)-α-GalNAc-(1-P-(strain ER-6P) or α-Neu5R-(2-3)-α-Gal-(1-P-strain Nagasaki) side chains, where R is the N-acetyl or N-glycolyl group. Glycolyl-neuraminic acid is widely found in animal glycoproteins, but it apparently has not been found in bacteria before, and might be important for the biology of this microorganism. Ac and Gc were present in equal amounts in the strain ER-6P but Nagasaki contained only about 20% of Gc substituent. Both strains produced the same LPS of a rough type with a single phosphorylated Kdo linking core and lipid A parts. LOS structure was similar to some strains of H. influenzae and contained a globotetraose terminal sequence.
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Vinogradov E, Frimmelova M, Toman R. Chemical structure of the carbohydrate backbone of the lipopolysaccharide from Piscirickettsia salmonis. Carbohydr Res 2013; 378:108-13. [PMID: 23673236 DOI: 10.1016/j.carres.2013.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 04/09/2013] [Accepted: 04/10/2013] [Indexed: 11/30/2022]
Abstract
Elucidation of the carbohydrate backbone structure of the lipopolysaccharide (LPS) from Piscirickettsia salmonis, the etiological agent of the salmonid rickettsial septicemia, is described. Structural information was established by a combination of monosaccharide and methylation analyses of LPS, and by NMR and mass spectrometries of oligosaccharides obtained through the use of various chemical degradations of the native polymer. The following structure of the backbone sugars was determined on the basis of the combined data from these experiments: [formula see text] The presence of two consecutive residues of diacetylated pseudaminic acid (Pse5,7Ac, 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid) in the LPS appears to be unique among polysaccharides containing this acidic sugar. Similarly, the presence of 4-aminoarabinose (Ara4N, 4-amino-4-deoxy-l-arabinopyranose) on O-4 of the α-GlcN1P of the lipid A moiety is a unique feature of this LPS.
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Rusakov YY, Krivdin LB, Papernaya LK, Shatrova AA. Stereochemical behavior of (77)Se-(1)H spin-spin coupling constants in pyrazolyl-1,3-diselenanes and 1,2-diselenolane. Magn Reson Chem 2012; 50:169-173. [PMID: 22367742 DOI: 10.1002/mrc.2863] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 10/31/2011] [Indexed: 05/31/2023]
Abstract
Conformational study of five derivatives of 2-(pyrazol-4-yl)-1,3-diselenane together with related 1,2-diselenolane in respect to the stereochemical trends of geminal and vicinal (77)Se-(1)H spin-spin coupling constants has been carried out by means of high-level theoretical calculations in combination with experiment. The marked dihedral angle dependences for both types of couplings accounted for the lone pair effect in the case of geminal coupling constants and the Karplus-type relationship for vicinal couplings have been established, which is of major importance for the stereochemical analysis of saturated selenium containing heterocycles.
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Affiliation(s)
- Yury Yu Rusakov
- Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
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49
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Rusakov YY, Krivdin LB, Orlov NV, Ananikov VP. Stereochemical study of the sterically crowded phenylselanylalkenes by means of (77)Se-(1)H spin-spin coupling constants. Magn Reson Chem 2011; 49:570-574. [PMID: 21818778 DOI: 10.1002/mrc.2784] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/30/2011] [Indexed: 05/31/2023]
Abstract
Stereochemical study of five sterically crowded phenylselanylalkenes obtained via the hydroselenation of either terminal or internal alkynes with benzeneselenol catalyzed by the nanosized Ni complexes has been carried out based on the experimental HMBC measurements and theoretical second order palarization propagator approach (SOPPA) calculations of their (77)Se-(1)H spin-spin coupling constants across double bond in combination with the energy-based theoretical conformational analysis performed at the MP2/6-311G** level. It has been found that studied phenylselanylalkenes adopt mainly skewed s-cis conformation with the noticeable out-of-plane deviations of the phenylselanyl and phenyl groups.
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Affiliation(s)
- Yury Yu Rusakov
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia
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Genta-Jouve G, Francezon N, Puissant A, Auberger P, Vacelet J, Pérez T, Fontana A, Mourabit AA, Thomas OP. Structure elucidation of the new citharoxazole from the Mediterranean deep-sea sponge Latrunculia (Biannulata) citharistae. Magn Reson Chem 2011; 49:533-536. [PMID: 21761452 DOI: 10.1002/mrc.2772] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 05/31/2023]
Abstract
Citharoxazole (1), a new batzelline derivative featuring a benzoxazole moiety, was isolated from the Mediterranean deep-sea sponge Latrunculia (Biannulata) citharistae Vacelet, 1969, together with the known batzelline C (2). This is the first chemical study of a Mediterranean Latrunculia species and the benzoxazole moiety is unprecedented for this family of marine natural products. The structure was mainly elucidated by the interpretation of NMR spectra and especially HMBC correlations.
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Affiliation(s)
- Grégory Genta-Jouve
- Laboratoire de Chimie des Molécules Bioactives et des Arômes UMR 6001 CNRS, Institut de Chimie de Nice, Faculté des Science, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 02, France
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