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Chen B, Fang Z, Zhang Y, Guan X, Lin E, Feng H, Zeng Y, Cai S, Yang Y, Huang Y, Chen Z. Two-Dimensional Laplace NMR Reconstruction through Deep Learning Enhancement. J Am Chem Soc 2024. [PMID: 39046081 DOI: 10.1021/jacs.4c05211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Laplace NMR is a powerful tool for studying molecular dynamics and spin interactions, providing diffusion and relaxation information that complements Fourier NMR used for composition determination and structure elucidation. However, Laplace NMR demands sophisticated signal processing algorithms such as inverse Laplace transform (ILT). Due to the inherently ill-posed nature of ILT problems, it is generally challenging to perform satisfactory Laplace NMR processing and reconstruction, particularly for two-dimensional Laplace NMR. Herein, we propose a proof-of-concept approach that blends a physics-informed strategy with data-driven deep learning for two-dimensional Laplace NMR reconstruction. This approach integrates prior knowledge of mathematical and physical laws governing multidimensional decay signals by constructing a forward process model to simulate relationships among different decay factors. Benefiting from a noniterative neural network algorithm that automatically acquires prior information from synthetic data during training, this approach avoids tedious parameter tuning and enhances user friendliness. Experimental results demonstrate the practical effectiveness of this approach. As an advanced and impactful technique, this approach brings a fresh perspective to multidimensional Laplace NMR inversion.
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Affiliation(s)
- Bo Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Ze Fang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yuebin Zhang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Xun Guan
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Enping Lin
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Hai Feng
- College of Artificial Intelligence, Application Technology Research Center of Artificial Intelligence, Xiamen City University, Xiamen, Fujian 361008, China
| | - Yunsong Zeng
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Shuhui Cai
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yu Yang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yuqing Huang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
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Chen B, Wu L, Chen Y, Fang Z, Huang Y, Yang Y, Lin E, Chen Z. GRIN-toolbox: A versatile and light toolbox for NMR inversion. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 355:107553. [PMID: 37713763 DOI: 10.1016/j.jmr.2023.107553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/17/2023]
Abstract
NMR technique serves as a powerful analytical tool with diverse applications in fields such as chemistry, biology, and material science. However, the effectiveness of NMR heavily relies on data post-processing which is often modeled as regularized inverse problem. Recently, we proposed the Generally Regularized INversion (GRIN) algorithm and demonstrated its effectiveness in NMR data processing. GRIN has been integrated as a friendly graphic user interface-based toolbox which was not detailed in the original paper. In this paper, to make GRIN more practically accessible to NMR practitioners, we focus on introducing the usage of GRIN-Toolbox with processing examples and the corresponding processing graphic interfaces, and the user manual is attached as Supplementary Material. GRIN-Toolbox is versatile and lightweight, where various kinds of data processing tasks can be completed with one click, including but not limited to diffusion-ordered spectroscopy processing, magnetic resonance imaging under-sampling reconstruction, Laplace (diffusion or relaxation) NMR inversion, spectrum denoising, etc. In addition, GRIN-Toolbox could be extended to more applications with user-designed inversion models and freely available at https://github.com/EricLin1993/GRIN.
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Affiliation(s)
- Bo Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Liubin Wu
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yida Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Ze Fang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yuqing Huang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yu Yang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Enping Lin
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China.
| | - Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China.
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Lin E, Zou N, Huang Y, Chen Z, Yang Y. Neural Network Method for Diffusion-Ordered NMR Spectroscopy. Anal Chem 2022; 94:2699-2705. [PMID: 35107988 DOI: 10.1021/acs.analchem.1c03883] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Diffusion-ordered NMR spectroscopy (DOSY) presents an essential tool for the analysis of compound mixtures by revealing intrinsic diffusion behaviors of the mixed components. For the interpretation of the diffusion information, intrinsically designed algorithms for a DOSY spectrum reconstruction are required. The estimated diffusion coefficients are desired to have consistency for all the spectral signals from the same molecule and good separation of signals from different molecules. For this purpose, we propose a novel method that adopts a coordinated multiexponential fitting to ensure the consistency of diffusion coefficients and apply a sparse constraint to enhance the robustness. A lightweight neural network is applied as an optimizer to solve this highly nonlinear and nonconvex optimization problem. The proposed method provides estimated diffusion coefficients with excellent distinguishment between species and outperforms the state-of-the-art reconstruction algorithms, such as the Laplacian inversion and the multivariate fitting methods.
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Affiliation(s)
- Enping Lin
- Department of Electronic Science, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Nannan Zou
- Department of Electronic Science, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yuqing Huang
- Department of Electronic Science, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Zhong Chen
- Department of Electronic Science, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yu Yang
- Department of Electronic Science, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
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4
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Dar SU, Ali S, Hameed MU, Zuhra Z, Wu Z. A facile synthesis, structural morphology and fluorescent properties of cross-linked poly(cyclotriphosphazene-co-1,3,5-tri(4-hydroxyphenyl)benzene) hybrid copolymer microspheres. NEW J CHEM 2016. [DOI: 10.1039/c6nj01578f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tunable size synthesis of fluorescent active microspheres with proposed unique chemical structure.
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Affiliation(s)
- Sami Ullah Dar
- Key Laboratory of Carbon Fibre and Functional Polymers (Beijing University of Chemical Technology)
- Ministry of Education
- Beijing 100029
- China
| | - Shafqat Ali
- Key Laboratory of Carbon Fibre and Functional Polymers (Beijing University of Chemical Technology)
- Ministry of Education
- Beijing 100029
- China
| | - Muhammad Usman Hameed
- Key Laboratory of Carbon Fibre and Functional Polymers (Beijing University of Chemical Technology)
- Ministry of Education
- Beijing 100029
- China
| | - Zareen Zuhra
- State Key Laboratory of Chemical Resource Engineering
- Institute of Science
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
| | - Zhanpeng Wu
- Key Laboratory of Carbon Fibre and Functional Polymers (Beijing University of Chemical Technology)
- Ministry of Education
- Beijing 100029
- China
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5
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Quantitative NMR for bioanalysis and metabolomics. Anal Bioanal Chem 2012; 404:1165-79. [PMID: 22766756 DOI: 10.1007/s00216-012-6188-z] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/04/2012] [Accepted: 06/08/2012] [Indexed: 01/16/2023]
Abstract
Over the last several decades, significant technical and experimental advances have made quantitative nuclear magnetic resonance (qNMR) a valuable analytical tool for quantitative measurements on a wide variety of samples. In particular, qNMR has emerged as an important method for metabolomics studies where it is used for interrogation of large sets of biological samples and the resulting spectra are treated with multivariate statistical analysis methods. In this review, recent developments in instrumentation and pulse sequences will be discussed as well as the practical considerations necessary for acquisition of quantitative NMR experiments with an emphasis on their use for bioanalysis. Recent examples of the application of qNMR for metabolomics/metabonomics studies, the characterization of biologicals such as heparin, antibodies, and vaccines, and the analysis of botanical natural products will be presented and the future directions of qNMR discussed.
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6
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Lucas LH, Wilson SF, Lunte CE, Larive CK. Concentration profiling in rat tissue by high-resolution magic-angle spinning NMR spectroscopy: investigation of a model drug. Anal Chem 2007; 77:2978-84. [PMID: 15859619 PMCID: PMC2519809 DOI: 10.1021/ac0482817] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The utility of high-resolution magic-angle spinning (HR-MAS) NMR for studying drug delivery in whole tissues was explored by dosing female Sprague-Dawley rats with topical or injectable benzoic acid (BA). In principle, HR-MAS NMR permits the detection of both intra- and extracellular compounds. This is an advantage over the previous detection of topically applied BA using microdialysis coupled to HPLC/UV as microdialysis samples only the extracellular space. Skin and muscle samples were analyzed by (1)H HR-MAS NMR, and BA levels were determined using an external standard solution added to the sample rotor. One to two percent of the BA topical dose was detected in the muscle, showing that BA penetrated through the dermal and subcutaneous layers. Since BA was not detected in the muscle in the microdialysis studies, the NMR spectra revealed the intracellular localization of BA. The amount of BA detected in muscle after subcutaneous injection correlated with the distance from the dosing site. Overall, the results suggest that HR-MAS NMR can distinguish differences in the local concentration of BA varying with tissue type, dosage method, and tissue proximity to the dosing site. The results illustrate the potential of this technique for quantitative analysis of drug delivery and distribution and the challenges to be addressed as the method is refined.
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Affiliation(s)
| | | | | | - Cynthia K. Larive
- * Corresponding author. Current address: Department of Chemistry, University of California, Riverside, CA 92521; phone: (951) 827-2990; fax: (951) 827-4713; e-mail:
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7
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Lucas LH, Yan J, Larive CK, Zartler ER, Shapiro MJ. Transferred nuclear overhauser effect in nuclear magnetic resonance diffusion measurements of ligand-protein binding. Anal Chem 2003; 75:627-34. [PMID: 12585494 DOI: 10.1021/ac020563o] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The drug discovery process relies on characterizing structure-activity relationships, since specific ligand-target interactions often result in important biological functions. Measuring diffusion coefficients by nuclear magnetic resonance spectroscopy is a useful way to study binding, because changes can be detected when a small ligand interacts with a macromolecular target. Diffusion coefficients can be miscalculated, however, due to magnetization transfer between the receptor and ligand. This transferred nuclear Overhauser effect (trNOE) disrupts the observed signal decay due to diffusion as a function of the experimental diffusion time. Since longer diffusion times also selectively edit free ligand signal, the measured diffusion coefficients become biased toward the fraction of bound ligand. Despite this discrepancy, under these experimental conditions, the trNOE selectively influences the measured signals of binding ligands and can be used to gain insight into ligand-protein interactions. These phenomena have been studied for caffeine and L-tryptophan, which bind to human serum albumin, and the antimalarial agent trimethoprim, which interacts with dihydrofolate reductase. The results provide insight into the nature of ligand-protein binding and are thus useful for elucidating the molecular features of the ligand that interact with the protein.
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Affiliation(s)
- Laura H Lucas
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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Keifer PA. NMR spectroscopy in drug discovery: tools for combinatorial chemistry, natural products, and metabolism research. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; 55:137-211. [PMID: 11127963 DOI: 10.1007/978-3-0348-8385-6_5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
NMR spectroscopy has enjoyed many advances recently, and the pace of development shows no signs of slowing. This article focuses on advances that have affected solution-state NMR. These advances fall into three general categories: new experimental techniques (new pulse sequence tools), improved hardware and more powerful software. These advances are allowing NMR to help solve important problems in the field of drug discovery. Their impact is widespread. NMR spectroscopy is now being used to determine protein structures, to monitor ligand-receptor binding, to study diffusion, to analyze mixtures using LC-NMR, to analyze solid-phase synthesis resins and to determine the structures of organic small molecules. NMR spectroscopy can provide both qualitative and quantitative information, and can be used in both routine analytical applications and demanding research applications. The applications described here can benefit numerous disciplines in drug discovery, including natural products research, synthetic medicinal chemistry, metabolism studies, drug production, quality control, rational drug design and combinatorial chemistry.
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Affiliation(s)
- P A Keifer
- Varian NMR Systems and NMR Consultant, 6329 South 172nd Street, Omaha, NE 68135, USA.
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9
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Grøtli M, Gotfredsen CH, Rademann J, Buchardt J, Clark AJ, Duus JO, Meldal M. Physical properties of poly(ethylene glycol) (PEG)-based resins for combinatorial solid phase organic chemistry: a comparison of PEG-cross-linked and PEG-grafted resins. JOURNAL OF COMBINATORIAL CHEMISTRY 2000; 2:108-19. [PMID: 10757090 DOI: 10.1021/cc990048c] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three series of poly(ethylene glycol) (PEG)-based polymers were synthesized and characterized with respect to their physical properties. Polyoxyethylene-polyoxypropylene (POEPOP), polyoxyethylene-polyoxetane (SPOCC), and polyoxyethylene-polystyrene (POEPS-3) were synthesized respectively by anion polymerization, cation polymerization, and radical polymerization. Both bulk and suspension modes were used to synthesize the polymers from derivatized PEG monomers (PEG 400, PEG 900, and PEG 1500). The three supports were compared with two commercially available PEG-grafted supports (TentaGel S OH, ArgoGel-OH) and two polystyrene supports (aminomethylated polystyrene [PS-NH2] and macroporous aminomethylated polystyrene [PLAMS]) with respect to their swelling properties, loading, NMR spectral quality, as well as solvent and reagent accessibility. Loadings of 0.3-0.7 mmol/g were obtained for the PEG-based resins. Swelling of the PEG-based resins was determined to be higher than that of the PEG-grafted resins and polystyrene supports. The PEG-based resins gave better resolved high-resolution NMR spectra than the PEG-grafted resins when examined by magic angle spinning nanoprobe (MAS) NMR spectroscopy. Moreover, fluorescence quenching of polymer bound 2-amino-benzoate by protonation with p-toluenesulfonic acid showed moderate to fast diffusion through the polymer depending on the solvent and the polymer matrix.
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Affiliation(s)
- M Grøtli
- Carlsberg Laboratory, Department of Chemistry, Valby, Denmark
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10
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Dixon AM, Larive CK. Modified pulsed-field gradient NMR experiments for improved selectivity in the measurement of diffusion coefficients in complex mixtures: application to the analysis of the Suwannee River fulvic acid. Anal Chem 1997; 69:2122-8. [PMID: 9183176 DOI: 10.1021/ac961300v] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To simplify the complex 1H NMR spectrum of a fulvic acid sample and gain structural and molecular size information, spectral editing techniques were used in conjunction with a general PFG NMR pulse sequence. These editing techniques exploit differences in T1 and T2 relaxation times as well as differences in coupling constants. The experiments were initially performed on a model mixture of glutamic acid and ethyl acetate in order to validate the method as a technique for measurement of diffusion coefficients. The editing experiments were then applied to the International Humic Substances Society Suwannee River fulvic acid standard. These editing techniques allowed more selective measurement of diffusion coefficients for broad classes of components within regions of the 1H NMR spectrum of the fulvic acid solution. The average radii of gyration calculated for the Suwannee River fulvic acid sample from the diffusion coefficients are in good agreement with literature values.
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Affiliation(s)
- A M Dixon
- Department of Chemistry, University of Kansas, Lawrence 66045, USA
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11
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Liu M, Nicholson JK, Lindon JC. High-resolution diffusion and relaxation edited one- and two-dimensional 1H NMR spectroscopy of biological fluids. Anal Chem 1996; 68:3370-6. [PMID: 8843135 DOI: 10.1021/ac960426p] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A new approach to the characterization of biomolecules in whole biological fluids is presented based on simplification of 1H NMR spectra by utilizing differences in molecular diffusion coefficients alone and combinations of relaxation and diffusion parameters. New NMR pulse sequences incorporating both spectral editing features together with solvent water resonance elimination are presented. The methods are exemplified using whole human blood plasma, and it is shown that it is possible to obtain NMR spectra of the slowly diffusing species (generally large molecules) by diffusion editing, the slowly relaxing species (generally small molecules) by spin relaxation editing, or spectra showing any range of molecular mobility using a combination of the two methods. The diffusion-based editing methods are also applicable to the selection of resonances in two-dimensional NMR spectroscopy of biofluids, and we show this for the first time by the production of 1H-1H diffusion-edited TOCSY spectra of human blood plasma where the resonance intensities are weighted according to the molecular diffusion coefficient. In this case, by measuring a diffusion-edited 1H-1H TOCSY NMR spectrum of plasma, it is possible to obtain signals from only the macromolecular components, and this may be of benefit in the analysis of blood lipoproteins. In complex biofluids, the combination of diffusion and relaxation editing brings about considerable spectral simplification leading to an easier resonance assignment process. We also demonstrate the production of 1H NMR spectra with intensities corresponding to diffusion coefficient rather than number of protons, and this opens up new possibilities for pattern recognition classification of samples based on altered molecular mobility features of biofluid components.
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Affiliation(s)
- M Liu
- Department of Chemistry, Birkbeck College, University of London, UK
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12
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Grue MR, Parolis H, Parolis LA. Structural investigation of the capsular polysaccharide of Escherichia coli O101 : K103 : H- using bacteriophage degradation and NMR spectroscopy. Carbohydr Res 1994; 262:311-22. [PMID: 7982222 DOI: 10.1016/0008-6215(94)84187-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
NMR spectroscopy was performed on the depyruvated capsular antigen of E. coli K103 and on the oligosaccharide obtained by depolymerisation of the native polysaccharide with a viral-borne endoglycanase. This capsular polysaccharide is the only one to be co-expressed with O group 101 and joins a small group of unusual capsular polysaccharides which possess pyruvic acid as the only acidic function. The primary structure was shown to be composed of the repeating unit: [formula: see text]
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Affiliation(s)
- M R Grue
- School of Pharmaceutical Sciences, Rhodes University, Grahamstown, South Africa
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13
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Nakajima H, Sugie H, Tsurui S, Ito M. Application of 1H-NMR spectroscopy for qualitative measurement of muscle carnitine levels. Clin Chim Acta 1994; 224:81-8. [PMID: 8174281 DOI: 10.1016/0009-8981(94)90123-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- H Nakajima
- Department of Pediatrics, Hamamatsu University, School of Medicine, Shizuoka, Japan
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14
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Ruiz-Cabello J, Cohen JS. NMR and the study of pathological state in cells and tissues. INTERNATIONAL REVIEW OF CYTOLOGY 1993; 145:1-63. [PMID: 8500979 DOI: 10.1016/s0074-7696(08)60424-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- J Ruiz-Cabello
- Department of Pharmacology, Georgetown University Medical School, Washington, D.C. 20007
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15
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Solid-state nuclear magnetic resonance spectroscopy of metal coordination complexes and organometallics. Coord Chem Rev 1991. [DOI: 10.1016/0010-8545(91)80003-v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Eugene M, Le Moyec L, de Certaines J, Desruennes M, Le Rumeur E, Fraysse JB, Cabrol C. Lipoproteins in heart transplantation: proton magnetic resonance spectroscopy of plasma. Magn Reson Med 1991; 18:93-101. [PMID: 2062246 DOI: 10.1002/mrm.1910180111] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Despite the major improvement in immunosuppressive therapy, noninvasive detection of heart graft rejection remains a challenge. As lipoproteins are involved in several immunomodulation mechanisms, we studied their proton NMR spectra in plasma from patients after heart transplantation. NMR data were compared to clinical and functional evaluation of rejection process. The total linewidth (TLW) of methyl and methylene peaks, mainly arising from lipoproteins, were significantly lower for patients without a rejection process than for patients before surgery and patients with evidences of a rejection process. When TLW values are referred to TLW on the 8th day for each patient, the sensitivity and the specificity of the test are increased, with resulting positive and negative predictive values of 90 and 91%, respectively. The results obtained on more than 400 samples from 46 patients justify the use of proton NMR spectroscopy as a clinical tool.
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Affiliation(s)
- M Eugene
- Institut de Génétique Moléculaire, Hôpital Saint Louis, Paris, France
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17
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Srivatsa GS, Chan MF, Chien DS, Tobias B. Detection and identification of endogenous small molecules in ocular tissues by proton nuclear magnetic resonance spectroscopy. Curr Eye Res 1991; 10:127-32. [PMID: 2036804 DOI: 10.3109/02713689109001740] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Proton nuclear magnetic resonance (nmr) spectra of rabbit ocular tissue homogenates (corneal epithelium, conjunctiva and iris ciliary body) and aqueous humor have been recorded for the first time by incorporation of a spin-spin relaxation reagent and use of the CPMG pulse sequence. A number of endogenous species such as lactate, glucose, alanine and valine have been observed in these ocular homogenates and significant differences have been noted in the distribution of these small molecules in the ocular tissues studied. This technique has been used to study the hydrolysis of acetylcholine by ocular esterases in the iris ciliary body.
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