Magnetic Resonance in Chemistry最新文献

{"title":"A Collaborative Study on Platform 1H Quantitative NMR Method Using Internal Calibration Methodology: Towards Capacity Building for Novices","authors":"Baoning Su,&nbsp;Jing Zhang,&nbsp;Xiaojuan Deng,&nbsp;Huiwen Deng,&nbsp;Songzi Jiang,&nbsp;Hui Fu,&nbsp;Jian Wang,&nbsp;Alan Wei,&nbsp;Qingwen Zhang,&nbsp;Jie Liu,&nbsp;Sunil Babu Paudel,&nbsp;Taijun Hang,&nbsp;Xiaofei Lu,&nbsp;Wei Zhang,&nbsp;Guosheng Ding,&nbsp;Li Gan,&nbsp;Xianzhong Yan,&nbsp;Yang Liu,&nbsp;Caiyu Zhang,&nbsp;Yang Liu","doi":"10.1002/mrc.5532","DOIUrl":"10.1002/mrc.5532","url":null,"abstract":"<div>\u0000 \u0000 <p>Over the past 20 years, the use of quantitative nuclear magnetic resonance (qNMR) technology has grown significantly in pharmaceutical industry. However, its broader adoption is often limited by specialized expertise required to implement best practices. Recent discussions within the qNMR community in China (qNMR-C) have highlighted the benefits of establishing an applicable qNMR platform method—one that serves as a universal approach, adaptable across multiple products. This approach aims to standardize a single set of qNMR parameters to address the majority of quantitative applications and making qNMR more accessible, particularly for researchers new to the field. The present study outlines the rationale behind the proposed qNMR platform method and demonstrates its strategic framework through a series of designed tests. Key parameters influencing qNMR accuracy and precision, including signal-to-noise ratio, data processing, integration approaches, relaxation delays, <i>T</i>₁ relaxation times, and sample weight, were systematically evaluated. A collaborative effort involving 12 NMR instruments across eight laboratories assessed the method's applicability and demonstrated its proper design space. Another objective of this study is to streamline the qNMR workflow, enabling novices to produce reliable, high-quality data early in their learning while ensuring reproducible and meaningful results. Furthermore, this work calls upon the global qNMR community to engage in the continued validation of the proposed platform method, fostering collective knowledge and verifying its robustness across diverse applications.</p>\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 8","pages":"534-544"},"PeriodicalIF":1.4,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144120022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Micellar Solubilization of Phenols With One or Two Hydroxyl Groups Using Biological Surfactant Rhamnolipid","authors":"Victor P. Arkhipov,&nbsp;Ruslan V. Arkhipov,&nbsp;Andrei Filippov","doi":"10.1002/mrc.5530","DOIUrl":"10.1002/mrc.5530","url":null,"abstract":"<p>We studied the solubilization of phenols with one and two hydroxyl groups (phenol, p-cresol, guaiacol, and pyrocatechol, resorcinol, hydroquinone) by micelles of the biological surfactant rhamnolipid using NMR diffusometry. We discuss the results within the framework of a model of two states of solubilizer molecules in solution: free in the aqueous phase and bound in surfactant micelles. The solubilization characteristics of rhamnolipid were calculated: the proportion of solubilized molecules р, micelle-water partition coefficient <i>K</i>_<i>m</i>, and molar solubilization ratio (MSR) depending on the concentration of rhamnolipid in solutions.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"508-517"},"PeriodicalIF":1.4,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5530","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity of Projections of Backbone 13Cα/15N Chemical Shielding Along Covalent Bonds to Protein Secondary Structure—An Ab Initio Study","authors":"Shaniya Sunny,&nbsp;Sivakumar Paramasivam","doi":"10.1002/mrc.5533","DOIUrl":"10.1002/mrc.5533","url":null,"abstract":"<div>\u0000 \u0000 <p>Statistical analysis of backbone ¹³C^α and ¹⁵N chemical shielding tensors (CST) computed using the DFT-GIAO method is presented for 40 alanine residues located centrally in three-residue segments extracted from α-helical and β-sheet regions of 12 proteins with high-resolution crystal structures. Our results show that the projections of ¹³C^α shielding along the three covalent bond directions, C^α–C^β, C^α–H^α, and C^α–N, exhibit significantly higher sensitivity to secondary structure than the principal components. The increased sensitivity is due to the changes in the orientation of ¹³C^α CST in the molecular frame of the two secondary structures. Similarly, the projections of backbone amide ¹⁵N shielding along the covalent bonds N–H, N–C^α and along the normal direction to the peptide plane have a reasonably higher sensitivity to the secondary structure than the principal components. Unlike ¹³C^α nuclei, the orientation of amide ¹⁵N CST in the molecular frame is found to be invariant in the two secondary structures. The calculated amide ¹⁵N chemical shielding anisotropies (CSA) are larger in helix than in sheet structure, consistent with the experimental ¹⁵N chemical shift studies reported in the literature. Furthermore, two-dimensional correlation plots of backbone ¹³C^α and ¹⁵N CSA parameters show a clear distinction between the two major secondary structure elements.</p>\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 8","pages":"524-533"},"PeriodicalIF":1.4,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144102205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-Uniform Sampling for Quantitative NOESY","authors":"William T. P. Darling,&nbsp;Sven G. Hyberts,&nbsp;Mate Erdelyi","doi":"10.1002/mrc.5529","DOIUrl":"10.1002/mrc.5529","url":null,"abstract":"<p>Non-uniform sampling (NUS) enables faster acquisition of NMR spectra. Concerns about spectral fidelity, particularly in high-dynamic-range experiments like NOESY, have limited its quantitative applications. In this study, we assessed whether optimised Poisson-gap sampling schemes can generate high-fidelity spectra suitable for quantitation and evaluated the effectiveness of NUS ranking tools, NUSscore and nus-tool, in identifying optimal sampling schemes. A total of 25,000 Poisson-gap sampling schemes were generated and ranked using NUSscore, with a subset of 11 of these spanning the score distribution, alongside 15 random-shuffle and the highest and lowest scoring Poisson-gap schemes determined using the signal apex-to-artefact ratio were used for comparison, all with 50% sampling coverage. Additionally, hybrid sampling schemes incorporating a long initial uniformly sampled section, termed US-NUS hybrid schemes, were evaluated. Spectral fidelity was evaluated on interproton distance accuracy, including the proportion of retained interproton distances and their deviation from uniformly sampled reference spectra. NUSscore showed a strong correlation with spectral fidelity. The peak-to-sidelobe ratio implemented in nus-tool showed no correlation, with the relative sensitivity metric showing a weak correlation. Signal-to-artefact apex ratio was also not predictive for identifying sampling schedules with maintained interproton distances. All Poisson-gap sampling schemes however outperformed random-shuffle. The US-NUS hybrids demonstrated improved interproton distance conservation than traditional Poisson-gap sampling schemes with a low seed dependence, making them a promising sampling schedule for quantitative NOESY analysis.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"495-507"},"PeriodicalIF":1.4,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5529","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aqueous Carbonation of Calcium Silicates With Different Ca/Si Ratios Studied by Solid-State NMR Spectroscopy","authors":"Rune Wittendorff Mønster Jensen,&nbsp;Jørgen Skibsted","doi":"10.1002/mrc.5528","DOIUrl":"10.1002/mrc.5528","url":null,"abstract":"<p>Calcium silicates react readily with CO₂ under aqueous conditions, forming CaCO₃ and silica gel. This is utilized to produce new cement binders and to sequester CO₂, thereby contributing to a lowering of the CO₂ footprint for the cement industry. The present work investigates aqueous carbonation of three hydraulic and three non-hydraulic calcium silicates with the aim of analyzing the impact of the Ca/Si ratio on the structure of the amorphous silica gel and on the extent and rate of carbonation. This information is obtained from ²⁹Si NMR experiments, whereas ¹³C NMR and FT-IR are used to characterize the polymorphic forms of CaCO₃ formed upon carbonation. The structure of the silica gel is not dependent on the type of carbonated calcium silicate or their Ca/Si ratio. In addition, the amounts of CaCO₃ from TGA analysis match well the theoretical maximum values. ²⁹Si and ²⁹Si{¹H} CP/MAS spectra of a commercial silica gel are very similar to those observed for the carbonated calcium silicates, which strongly suggests that a hydroxylated silica gel without incorporated Ca ions constitutes the silica gel in carbonated calcium silicates. From ¹³C NMR and FT-IR, it is found that calcite is the principal CaCO₃ polymorph for all samples carbonated for 6 h. However, aragonite and calcite do co-exist during the initial carbonation (20 min) of γ-Ca₂SiO₄. Comparison of the carbonation evolution for the hydraulic and non-hydraulic calcium silicates strongly suggests that an early hydration and formation of C-S-H is not a required initial step in the aqueous carbonation process.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"476-494"},"PeriodicalIF":1.4,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5528","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NMR as a Discovery Tool: Exploration of Industrial Effluents Discharged Into the Environment","authors":"Kiera Ronda,&nbsp;Jeremy Gauthier,&nbsp;Khanisha Singaravadivel,&nbsp;Peter M. Costa,&nbsp;Katelyn Downey,&nbsp;William W. Wolff,&nbsp;Daniel H. Lysak,&nbsp;Jacob Pellizzari,&nbsp;Owen Vander Meulen,&nbsp;Katrina Steiner,&nbsp;Amy Jenne,&nbsp;Monica Bastawrous,&nbsp;Zainab Ng,&nbsp;Agnes Haber,&nbsp;Benjamin Goerling,&nbsp;Venita Busse,&nbsp;Falko Busse,&nbsp;Colin Elliot,&nbsp;Scott Mabury,&nbsp;Mohamed Ateia,&nbsp;Derek C. G. Muir,&nbsp;Robert J. Letcher,&nbsp;Krish Krishnamurthy,&nbsp;Sonya Kleywegt,&nbsp;Karl J. Jobst,&nbsp;Myrna J. Simpson,&nbsp;Andre J. Simpson","doi":"10.1002/mrc.5527","DOIUrl":"10.1002/mrc.5527","url":null,"abstract":"<p>NMR provides unprecedented molecular information, urgently needed by environmental researchers and policy makers. However, NMR is underutilized in environmental sciences due to the lack of available technologies, limited environmental-specific training opportunities, and easy-to-use workflows. NMR has considerable potential as a discovery tool for novel pollutants, and by-products, exemplified by the recent discovery of the degradation by-product of a rubber additive, 6PPD-quinone, now considered one of the most toxic compounds presently known. This work represents a proof-of-concept case study highlighting the use of NMR to profile effluents from 38 industries across Ontario, Canada. Wastewater effluents from various industrial sectors were analyzed using several 1D and 2D ¹H/¹³C NMR and ¹⁹F experiments and were screened both unconcentrated and after lyophilization. Common species could be identified using human metabolic NMR databases, but environmental-specific NMR databases desperately need further development. An example of manually identifying unusual NMR signatures is included; these resulted from phosphinic and phosphonic acids originating from the electroplating industry, for which the environmental impacts are not well understood. Basic ¹H NMR quantification is performed using ERETIC, while an optimized approach combining relaxation agents and steady-state-free-precession ¹⁹F NMR, to reduce detection limits (at 500 MHz) to sub-ppb (&lt; 1 μg/L) in under 15 min, is demonstrated. The future potential of benchtop NMR (80 MHz) is also considered. This paper represents a guide to others interested in applying NMR spectroscopy to environmental media and demonstrates the potential of NMR as a complementary tool to assist MS in environmental pollutant and by-product discovery.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"453-475"},"PeriodicalIF":1.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5527","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143989517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical Comparison of Two Quantitative HSQC Methods for the Absolute Quantitation of Metabolites","authors":"Jérémy Marchand,&nbsp;Estelle Martineau,&nbsp;Jonathan Farjon,&nbsp;Patrick Giraudeau","doi":"10.1002/mrc.5525","DOIUrl":"10.1002/mrc.5525","url":null,"abstract":"<div>\u0000 \u0000 <p>Multiple 2D HSQC NMR methods have been developed for the absolute quantitation of metabolites in complex mixtures without need for external calibration or standard additions. However, analytical comparison between these methods is lacking. This study aims at comparing the performance of two “intrinsically quantitative” heteronuclear methods for the targeted quantitation of metabolite mixtures: HSQC₀ and Q QUIPU HSQC. Each method was applied on a model metabolite mixture in the same total experiment time. Both methods were accelerated with non-uniform sampling (NUS), then further accelerated by combining NUS with variation of the pulse sequence repetition time (VRT). Multiple analytical metrics were evaluated and compared for quantitation, including trueness, repeatability, and sensitivity. Globally, accelerated versions of the pulse sequences, using NUS and VRT, performed better than NUS-only acquisitions. On the one hand, provided enough sensitivity is achieved, better performance was observed for HSQC₀, which also appears as a more user-friendly technique. On the other hand, Q QUIPU HSQC was shown to be more repeatable and more sensitive.</p>\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"434-444"},"PeriodicalIF":1.4,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144027543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure Confirmation of Quinazolinone and Hydroindole Using Residual Dipolar Couplings From Polyarylisocyanide Liquid Crystal","authors":"Gao-Wei Li,&nbsp;Shuai-Hua Shi,&nbsp;Shu-Sen Li,&nbsp;Xiao-Juan Wang,&nbsp;Yuan-Yuan Gao,&nbsp;Lan-Tao Liu,&nbsp;Xinxiang Lei","doi":"10.1002/mrc.5526","DOIUrl":"10.1002/mrc.5526","url":null,"abstract":"<div>\u0000 \u0000 <p>Determining the constitution and configuration is a critical step in characterizing the structure of small molecules. In addition to the classical nuclear magnetic resonance (NMR) method conducted in isotropic solutions, the emerging anisotropic NMR parameters such as residual dipolar couplings (RDCs) were also employed to clarify the structures of organic molecules. These RDCs not only confirmed that the unexpectedly synthesized product was a quinazolinone but also validated the relative configuration of the diastereoisomeric hydroindole in a polyarylisocyanide lyotropic liquid crystalline solution through the induction of anisotropy. Singular value decomposition (SVD) was employed to fit the experimental RDC data against the low-energy conformational sets of an unexpected synthetic product, which were calculated using density functional theory (DFT). This analysis aimed to identify the correct molecular connection sites. Furthermore, the method was applied to determine the correct relative configuration between two possible diastereoisomers.</p>\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"445-452"},"PeriodicalIF":1.4,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144000723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Solid-State Carbon-13 CP-MAS NMR Analysis of Carboxymethyl Cellulose Sodium Salt (CMC) Derived From Cotton and Other Sources","authors":"S. Recillas,&nbsp;G. Escobar-Vásquez,&nbsp;V. M. Castaño,&nbsp;A. Martinez-Richa","doi":"10.1002/mrc.5524","DOIUrl":"10.1002/mrc.5524","url":null,"abstract":"<div>\u0000 \u0000 <p>Synthetic and commercial carboxymethyl cellulose (CMC) sodium salts were analyzed by CP-MAS ¹³C-NMR and plasma emission analysis. CMC was synthesized in the lab from cotton alkali cellulose and sodium chloroacetate. The progressive changes in the chemical composition and morphology (and reflected in the degree of substitution, DS) were followed by solid-state NMR. Observed differences in solid-state NMR spectra are discussed in terms of DS, chemical composition, dynamics, and polymorphism. The effect of molecular weight in CMC morphology and dynamics can be assessed by small differences observed in peak shapes and peak positions in the CP-MAS spectra.</p>\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 7","pages":"428-433"},"PeriodicalIF":1.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144030859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterophyllin B: Combining Isotropic and Anisotropic NMR for the Conformational Analysis of a Natural Occurring Cyclic Peptide","authors":"Anton F. Ketzel,&nbsp;Yang Hu,&nbsp;Xiao-Lu Li,&nbsp;Jiaqian Li,&nbsp;Xinxiang Lei,&nbsp;Han Sun","doi":"10.1002/mrc.5523","DOIUrl":"10.1002/mrc.5523","url":null,"abstract":"<p>Heterophyllin B is a natural occurring cyclic peptide with diverse attributed bioactivities. NMR-based conformational analysis of cyclic peptides often poses a challenge due to limited isotropic solution-state NMR data. In this study, we combined isotropic and anisotropic NMR observables including <i>J</i>-coupling, NOEs, amide proton temperature coefficients, and residual dipolar couplings (RDCs), which enabled the determination of a minimal conformational ensemble of heterophyllin B in methanol at density functional theory (DFT) accuracy. For conformational sampling of a cyclic peptide with a high degree of conformational freedom, we proposed a computational strategy that combines the Conformer–Rotamer Ensemble Sampling Tool (CREST) with the Commandline Energetic SOrting (CENSO). This combined computational and NMR-based approach offers a robust framework for the conformational analysis of cyclic peptides.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"63 5-6","pages":"417-423"},"PeriodicalIF":1.4,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5523","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143909559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}