Journal of Magnetic Resonance Open最新文献

{"title":"Improved 2D hydride detection for NMR-chemosensing via p‐H2 Hyperpolarization","authors":"Ruud L.E.G. Aspers,&nbsp;Marco Tessari","doi":"10.1016/j.jmro.2024.100170","DOIUrl":"10.1016/j.jmro.2024.100170","url":null,"abstract":"<div><div>2D NMR zero-quantum spectroscopy offers a robust and convenient way to resolve hydride resonances in non-hydrogenative ParaHydrogen Induced Polarization experiments. This approach has been recently applied to the detection and quantification of dilute components in biofluids and natural extracts. For certain classes of analytes, however, modulation of the zero-quantum coherence occurs at several kiloHertz frequency, which determines long measurement times for attaining the desired resolution in the indirect dimension. Here, we propose an alternative 2D approach to measure high-resolution NMR spectra that affords enhanced sensitivity and reduced experimental time for optimal sample throughput.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100170"},"PeriodicalIF":2.624,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A practical guide to metal ions dynamic nuclear polarization in materials science","authors":"Ilia B. Moroz,&nbsp;Neta Katzav,&nbsp;Asya Svirinovsky-Arbeli,&nbsp;Michal Leskes","doi":"10.1016/j.jmro.2024.100173","DOIUrl":"10.1016/j.jmro.2024.100173","url":null,"abstract":"<div><div>In this protocol we outline the practical aspects and methodology for performing metal ions-based dynamic nuclear polarization (MI-DNP), focusing on materials science applications. In MI-DNP polarization is transferred from unpaired electrons of paramagnetic metal ions to nearby nuclear spins, thereby increasing the sensitivity of NMR spectroscopy. The protocol encompasses detailed steps for (i) selecting suitable metal ion dopant based on chemical, structural and electron paramagnetic resonance (EPR) considerations, (ii) characterizing the concentration, homogeneity and EPR properties of the dopant and (iii) performing the MI-DNP experiment itself, including optimization of the field position and reliable assessment of the DNP enhancement factors. By adhering to this protocol, the interested reader can implement the MI-DNP approach in an efficient way, facilitating spectroscopic studies of functional materials.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100173"},"PeriodicalIF":2.624,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current state of the art of analyte scope in urine metabolome analysis by non-hydrogenative PHIP","authors":"Nele Reimets,&nbsp;Kerti Ausmees,&nbsp;Indrek Reile","doi":"10.1016/j.jmro.2024.100171","DOIUrl":"10.1016/j.jmro.2024.100171","url":null,"abstract":"<div><div>Non-hydrogenative PHIP (nh-PHIP) is an NMR signal enhancement technique that offers several orders of magnitude gains in detection sensitivity. It is one of the few hyperpolarization methods that have been demonstrated to be applicable to chemical analysis of biological samples and potentially metabolomics. It is, however, a chemoselective method and needs to be tuned to particular analyte and metabolite classes at a time.</div><div>Herein, we present a systematic study where we apply four nh-PHIP modifications to urine samples from two different species – human and dog. Firstly, this allows to explore the whole analyte class scope and present what information is nh-PHIP capable of providing by varying the composition of the nh-PHIP catalyst system and the sample preparation protocol. Secondly, comparing hyperpolarized spectra from urines from different species demonstrates that this hyperpolarization technique is robust and tolerant of possibly considerable matrix differences: signals of the same metabolites appear at same chemical shifts from urines that differ from one-another much more than is likely in a realistic metabolomics study. Thereby we propose the idea that nh-PHIP is ready for application in metabolomics experiments.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100171"},"PeriodicalIF":2.624,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron spin polarization in the triplet state of methoxy-substituted phosphorus(V) tetraphenyl porphyrins","authors":"D. Panariti ,&nbsp;B.J. Bayard ,&nbsp;A. Barbon ,&nbsp;Y.E. Kandrashkin ,&nbsp;P.K. Poddutoori ,&nbsp;A. van der Est ,&nbsp;M. Di Valentin","doi":"10.1016/j.jmro.2024.100169","DOIUrl":"10.1016/j.jmro.2024.100169","url":null,"abstract":"<div><div>Photoexcited triplet states of porphyrins are of great relevance in various applications due to their high yield, long lifetime, and strong electron spin polarization. This study delves into properties and spin dynamics of the triplet state of a series of hypervalent phosphorus(V) porphyrins. Transient Electron Paramagnetic Resonance (TrEPR) measurements, supported by quantum chemical calculations as well as by optical absorption/luminescence experiments, reveal that, unlike singlet states, the lowest triplet state does not exhibit charge-transfer (CT) character upon photoexcitation. However, the presence of excited CT singlet states alters the intersystem crossing in phosphorus(V) porphyrins, leading to a sign change in the initial multiplet polarization of the photoexcited triplet state. TrEPR results further demonstrate that significant net polarization develops in the triplet states of the phosphorus(V) porphyrins due to the dynamic Jahn-Teller effect. Yet, this effect remains largely unaffected by differences in their molecular structures.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100169"},"PeriodicalIF":2.624,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural abundance 195Pt-13C correlation NMR spectroscopy on surfaces enabled by fast MAS dynamic nuclear polarization","authors":"Zhuoran Wang ,&nbsp;Thomas C. Robinson ,&nbsp;Domenico Gioffrè ,&nbsp;Rochlitz Lukas ,&nbsp;David Gajan ,&nbsp;Aaron J. Rossini ,&nbsp;Christophe Copéret ,&nbsp;Anne Lesage","doi":"10.1016/j.jmro.2024.100167","DOIUrl":"10.1016/j.jmro.2024.100167","url":null,"abstract":"<div><div>Surface organometallic chemistry has developed as an effective strategy for the rational design and synthesis of well-defined, single-site Pt-based heterogeneous catalysts. Given its high sensitivity to changes in electronic structure, ¹⁹⁵Pt solid-state NMR spectroscopy offers a unique approach to investigate the chemical structure and local environment of Pt surface sites, providing invaluable insights for establishing structure-activity relationships. However, this approach is typically hindered by severe sensitivity issues, due to the low loading of Pt sites and the often-encountered large ¹⁹⁵Pt chemical shift anisotropies. To overcome this limitation, ¹⁹⁵Pt NMR signature of surface metal centers can be indirectly detected through protons. Indirect detection on ¹³C spins, has also been demonstrated to be feasible by combining isotopic labeling with dynamic nuclear polarization (DNP). Here, we extend this methodology to a supported Pt complex at natural abundance. The material was prepared by grafting <strong>(COD)PtMeOSi(O<em>t</em>Bu)₃</strong> (COD = 1,5-cyclooctadiene, Me = methyl and <em>t</em>Bu = <em>tert</em>‑butyl) onto partially dehydroxylated silica. DNP enhanced two-dimensional through-bond ¹³C{¹⁹⁵Pt} heteronuclear correlation experiments were successfully implemented at fast magic angle spinning. They enabled the detection of the 0.37 % NMR-responsive surface species, thereby showcasing the remarkable sensitivity of this approach and its broad applicability. Key bonding information was obtained by measuring the correlated ¹³C and ¹⁹⁵Pt isotopic chemical shifts as well as ¹<em>J</em>(¹³C-¹⁹⁵Pt) coupling constants, confirming directly the coordination structure of the surface Pt sites.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100167"},"PeriodicalIF":2.624,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear hyperpolarization in electron-transfer proteins: Revealing unexpected light-induced 15N signals with field-cycling magic-angle spinning NMR","authors":"Patrick Kurle-Tucholski ,&nbsp;Luca Gerhards ,&nbsp;Yonghong Ding ,&nbsp;Yunmi Kim ,&nbsp;Irina S. Anisimova ,&nbsp;A. Alia ,&nbsp;Ilia A. Solov'yov ,&nbsp;Jörg Matysik","doi":"10.1016/j.jmro.2024.100168","DOIUrl":"10.1016/j.jmro.2024.100168","url":null,"abstract":"<div><div>The solid-state photo-CIDNP (photo-chemically induced dynamic nuclear polarization) effect allows for nuclear hyperpolarization, i.e., non-Boltzmann nuclear spin population. The effect relies on the light-induced formation of a spin-correlated radical pair (SCRP) and has been observed in various photosynthetic reaction center (RC) proteins and flavin-containing light, oxygen, voltage (LOV) proteins. Both systems exhibit strongly enhanced NMR signals originating from the electron transfer partners. Here, we present experimental data on the magnetic field dependence of the ¹⁵N solid-state photo-CIDNP effect in both phototropin LOV1 C57S from <em>Chlamydomonas reinhardtii</em> and the bacterial photosynthetic RC from <em>Rhodobacter sphaeroides.</em> Using a pneumatic field-cycling system, samples containing a frozen solution of the proteins are explored between 0.25 T and 9.4 T. Both systems yield hyperpolarized ¹⁵N NMR signals across the entire magnetic field range originating from the electron transfer moieties. Also, in both systems, hyperpolarized signals from unexpected positions are detected between 1.0 T and 2.0 T: position N-1 of the flavin in the LOV1 protein and the τ-N of the axial magnesium-coordinating histidine of the donor. A first attempt to explain the occurrence of these unexpected signals based on quantum chemical calculations is presented.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100168"},"PeriodicalIF":2.624,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement and modeling of xenon gas transfer in the human brain with 1H and hyperpolarized 129Xe MRI","authors":"Graham Norquay ,&nbsp;Madhwesha R Rao ,&nbsp;Jim M Wild","doi":"10.1016/j.jmro.2024.100166","DOIUrl":"10.1016/j.jmro.2024.100166","url":null,"abstract":"<div><h3>Background</h3><div>The feasibility of imaging hyperpolarized ¹²⁹Xe dissolved in brain tissue following inhalation of xenon gas in the lungs has recently been demonstrated in humans. The image contrast in ¹²⁹Xe brain MRI represents a combination of factors, including regional perfusion, polarization decay and gas transfer rate across the blood-brain barrier.</div></div><div><h3>Purpose</h3><div>To investigate the repeatability of hyperpolarized ¹²⁹Xe brain MRI in healthy normal individuals and to identify the dominant mechanisms of image contrast by assessing voxel-wise correlation between HP ¹²⁹Xe brain MRI and models of ¹²⁹Xe brain uptake derived from ¹H arterial spin labeling (ASL) perfusion mapping.</div></div><div><h3>Materials and Methods</h3><div>To assess repeatability, 3 sets of hyperpolarized ¹²⁹Xe brain images were acquired from 5 healthy volunteers. Quantitative maps of the human brain, including cerebral blood flow, volume and predicted xenon uptake, were derived from ¹H arterial spin labeling and <em>T</em>₂-weighted MRI. These maps were then spatially cross-correlated with hyperpolarized ¹²⁹Xe brain MRI.</div></div><div><h3>Results</h3><div>Signal to noise ratios of 8.7–17.7 were observed across volunteers for a voxel size of 8 × 8 × 50 mm³ with intra-subject repeatability of between 6 and 29 %. Hyperpolarized ¹²⁹Xe brain images showed voxel-wise correlations with cerebral blood flow (<em>R</em> = 0.32 to 0.62), volume (<em>R</em> = 0.33 to 0.63) and predicted xenon uptake (<em>R</em> = 0.34 to 0.63), but did not correlate with arterial transit time (<em>R</em> = 0.05 to 0.26).</div></div><div><h3>Conclusion</h3><div>Voxel-wise cross correlation between ¹²⁹Xe and ¹H ASL suggests that the regional quantity of dissolved xenon delivered by cerebral blood flow is the dominant mechanism of image contrast in HP ¹²⁹Xe brain MRI, assuming normal blood-brain barrier function. Combining ¹H and ¹²⁹Xe brain MRI provides new opportunities to quantitatively investigate brain pathophysiology and function.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100166"},"PeriodicalIF":2.624,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"13C-Formate as an indirect low-temperature 1H lineshape polarimeter","authors":"Stuart J. Elliott ,&nbsp;Quentin Stern,&nbsp;Sami Jannin","doi":"10.1016/j.jmro.2024.100162","DOIUrl":"10.1016/j.jmro.2024.100162","url":null,"abstract":"<div><div>¹H polarization quantification is important for dissolution-dynamic nuclear polarization (<em>d</em>DNP) but can be cumbersome due to the requirement of acquiring thermal equilibrium signals and measurements that are complicated by large background signals. ¹H nuclear magnetic resonance (NMR) spectra can also be deleteriously influenced by line distortions linked with radiation damping from ¹H DNP and cannot be used for accurate calculation of ¹H polarization. Determining ¹H polarization via immediate ¹³C lineshape analysis of a simple molecule removes such complications. We present ¹³C-sodium formate as a straightforward system for indirect ¹H polarimetry. The ¹³C NMR spectra acquired under <em>d</em>DNP conditions have distinct features that are readily reproduced with ¹³C lineshape simulations. ¹H polarizations built-up during ¹H DNP were indirectly inferred by fitting simulations to ¹³C lineshapes. We provide the <em>MATLAB</em> scripts used for ¹³C lineshape analysis in order that the method can be readily implemented in other laboratories.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100162"},"PeriodicalIF":2.624,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of biomolecular dynamics by sensitivity-enhanced 1H–2H CPMAS NMR using matrix-free dynamic nuclear polarization","authors":"Thomas Biedenbänder ,&nbsp;Aryana Rodgers ,&nbsp;Mirjam Schröder ,&nbsp;Liliya Vugmeyster ,&nbsp;Björn Corzilius","doi":"10.1016/j.jmro.2024.100161","DOIUrl":"10.1016/j.jmro.2024.100161","url":null,"abstract":"<div><div>Molecular dynamics of functional groups contain valuable information about structural properties and functional activities in biomolecules. NMR spectroscopy is a sensitive tool for the investigation of molecular dynamics over a wide range of timescales and thus may deepen the understanding of the biomolecules of interest. Here, we present an approach to use DNP-enhanced ²H NMR to study dynamics of selectively deuterated methyl groups in insoluble proteins such as amyloid beta (Aβ) fibrils. We adopted and optimized the matrix-free DNP approach by varying the amount of added polarizing agent as well as the rehydration level of model proteins. We show that the DNP enhancement obtained in ¹H–²H cross-polarization (CP) MAS spectra may increase the sensitivity for selectively deuterated Aβ fibril samples by more than one order of magnitude, accelerating the collection of spin-lattice relaxation data in the DNP-accessible temperature range between 100 and 150 K by up to 400-fold. However, below the coalescence temperature, which describes the transition from the fast to the slow exchange regime, the experimentally obtained relaxation time constants suffer from a paramagnetic relaxation enhancement effect due to the presence of the polarizing agent. This seems to be a general effect for biomolecules as it is also confirmed for two other protein model systems. Our demonstration opens the possibility to extend the scope of ²H NMR for dynamics measurements to effective concentrations and/or temperatures below what is currently accessible; however, the observed interplay between paramagnetic relaxation and molecular dynamics also emphasizes the necessity for a better understanding of relaxation effects in DNP-enhanced NMR.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100161"},"PeriodicalIF":2.624,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DNP enhanced solid-state NMR – A powerful tool to address the surface functionalization of cellulose/paper derived materials","authors":"Mark V. Höfler ,&nbsp;Jonas Lins ,&nbsp;David Seelinger ,&nbsp;Lukas Pachernegg ,&nbsp;Timmy Schäfer ,&nbsp;Stefan Spirk ,&nbsp;Markus Biesalski ,&nbsp;Torsten Gutmann","doi":"10.1016/j.jmro.2024.100163","DOIUrl":"10.1016/j.jmro.2024.100163","url":null,"abstract":"<div><div>This concept summarizes recent advances in development and application of DNP enhanced multinuclear solid-state NMR to study the molecular structure and surface functionalization of cellulose and paper-based materials. Moreover, a novel application is presented where DNP enhanced ¹³C and ¹⁵N solid-state NMR is used to identify structure moieties formed by cross-linking of hydroxypropyl cellulose. Given these two aspects of this concept-type of article, we thus combine both, a review on recent findings already published and unpublished recent data that complement the existing knowledge in the field of characterization of functional lignocellulosic materials by DNP enhanced solid-state NMR.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100163"},"PeriodicalIF":2.624,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}