NMR Methods/Theory
Understanding antimicrobial activity in live cells
Ángela Serrano Sánchez – @Angelasrno99
We have optimised a new, simple methodology to assess membrane permeability of drugs making use of the paramagnetic relaxation enhancement (PRE) effect in lipid vesicles that is applicable to any type of cell membrane. Using this assay, we have been able to find important differences in the permeability of new families of antimicrobial compounds, providing unique information for the further development of this family of compounds. In addition, we have now expanded this assay to live cells making use of a NMR-coupled bioreactor. Using this set up, we are to monitor both the drug permeation into live cells, as well as changes in the bacterial metabolism as a result of the antimicrobial agent added.
Novel Sampling Schemes for the Indirect Detection of Ultrawideline 195Pt Solid-State NMR Spectra for the Characterization of Heterogeneous Catalysts
Benjamin Atterberry – @BenjaminAtterb1
The noble metal platinum is widely utilized in numerous catalytic processes. However, the structure of Pt sites in heterogeneous catalysts are often ill-defined. Herein, we introduce a series of solid-state NMR experiments that use indirect detection of a sensitive spy nucleus (1H or 31P) to rapidly acquire 195Pt NMR spectra.
Structural characterization by NMR spectroscopy of a DnaX mini-intein derived from Spirulina platensis
Soumendu Boral – @BoralSoumendu
Inteins perform protein splicing reaction. We solved solution NMR structure (PDB code: 7CFV) of a 136-residue DnaX mini-intein. The NMR structural ensemble has backbone and heavy atom RMSD of 0.27 and 0.52 Å, respectively. NMR-based HX and 15N-relaxation experiments showed the presence of a very stable core and conserved motions.
Hyperpolarising Nitrogen
Callum Gater – @CallumGater1
In this work we show how the polarisation potential of parahydrogen can be realised by Signal Amplification By Reversible Exchange (SABRE) to hyperpolarise 15N for use in reaction monitoring, 15N DOSY and routes towards hyperpolarised 15N2 gas for use in a potential lung imaging technique in the future.
NMRTools.jl: a simple, open source interface for NMR data in Julia
Chris Waudby – @chris_waudby
Julia is a modern language optimised for scientific computation. To facilitate the use of Julia by the NMR community, here we introduce NMRTools.jl, an open source package providing an interface to import and visualise NMR data. Interested users are welcomed to contribute to the development of this ongoing project.
Development of Plastic-Crystal Based Electrolytes Using Novel Dicationic Salts
Shanika Abeysooriya – @IamShanika_SL
Organic ionic plastic crystals (OIPCs) are promising candidates as solid-state electrolyte materials for Li battery applications. OIPCs consist entirely of ions and possess a long-range ordered crystalline lattice but short-range disorder. They possess advantageous properties such as non-volatility, non-flammability, high ionic conductivity, and wide electrochemical window. This has prompted researchers to investigate different combinations of cations and anions to produce new OIPCs. Many mono-cation and anion combinations have been investigated to develop new plastic crystal systems. However, the unique structure of dications increase the number of possible combinations, for new materials with wider range of physicochemical properties. As structure-property relationships related to dicationic organic salts are seldom explored, this study reports the synthesis and characterization of two new dicationic salts, 1,2-bis(N-ethylpyrrolidinium)ethane bis(trifluoromethanesulfonyl)imide ([C2-Pyrr2][TFSI]2) and 1,2-bis(N-n-propylpyrrolidinium)ethane bis(trifluoromethanesulfonyl)imide ([C2-Pyrr3][TFSI]2). The physicochemical properties and local structure dynamics were investigated by solid-state NMR and correlated with thermal analysis and the ionic conductivity. [C2-Pyrr3][TFSI]2, with the longer alkyl-side chain, showed improved transport properties compared to [C2-Pyrr2][TFSI]2. Further exploration of the organic salts as potential electrolyte material was conducted by mixing with 10 mol% lithium TFSI, where highest increase in conductivity was recorded for 10 mol% LiTFSI in [C2-Pyrr3][TFSI]2. Solid-state NMR analysis revealed that Li+ and [TFSI]- ions acted as the major contributors for ionic conductivity, while the dications in the bulk structure were less mobile.
New Methods targetting Battery Material Characterization
Isha Yadav – @IshaYadav_1809
Battery is efficient and safer energy storage device . We will use advanced NMR instrumentation and pulse sequence (19 F – 7 Li correlation ) to study solid polymer electrolytes to establish ion conductivity – structural relationship , stability- structural relationship and through DNP we can deal with electrode-electrolyte interface.
A New solid-state NMR Homonuclear Correlation Method and its Application for Detecting Nucleotides and Their Hydrogen Bonds in Intact Viral RNA
Orr Simon Lusky – @ItIsLusk
We present a new solid state NMR method we developed for studying biological macromolecules called ‘Pulse induced resonance with angular dependent total enhancement’ (PIRATE). We demonstrate a new resonance condition, and the application on finding hydrogen bond patterns in intact viral RNA harvested directly from the MS2 bacteriophage.
Quantitative NMR of chloride by an accurate internal standard approach
Jared Scott Wood – @jaredscottwood
Quantitative analysis of heteroatoms in small molecule active pharmaceutical ingredients is crucial for the development of modern therapeutics. Here we present a robust and generally applicable 35Cl solution qNMR method to assay the level of chloride in pharmaceutical compounds.
Broadband Cross Polarization to Half-Integer Quadrupolar Nuclei
James J. Kimball – @jimmy_kimball97
In this work, we present new research on the successful implementation of the Broadband Adiabatic-Inversion Cross Polarization pulse sequence for the acquisition of Ultra-Wideline NMR spectra of half-integer quadrupolar nuclei using low power pulses. Numerical simulations are used to explore underlying mechanisms and are correlated with experimental results.
Mrsimulator: A Python Package for Fast Solid-State NMR Spectral Simulation
Matthew D. Giammar – @Matth__3w
Mrsimulator is an open-source and free Python package for fast computation and analysis of NMR spectra compatible with other modern packages like Scikit-learn, Keras, and nmrglue. Mrsimulator offers least-squares fitting of 1D and 2D spectra out-of-the-box and can run in Jupyter Notebooks. Documentation: https://mrsimulator.readthedocs.io/en/latest/
NMR Online - Leave the desktop behind
Simon P. Skinner – @nmronline
NMR Online is an NMR spectroscopy data analysis platform. It's NMR community-led, web-based, cloud-driven. Built with leading tech, and a test-driven approach. NMR Online – BETA features a CEST workflow to demonstrate how this analysis can be done in under 10 clicks! Please DM for login information.
Stable MAS NMR at Ultralow Temperatures from 24 - 100 K
Raj Chaklashiya – @RajChaklashiya
It is the NMR spectroscopist’s dream to perform Magic-Angle Spinning (MAS) NMR at temperatures below 100 K for significant Boltzmann polarization signal gains. Here we demonstrate this using NMR with stable MAS spinning at 24 – 100 K using a novel helium gas recirculation system developed in collaboration with JEOL.
Catch me if you can - new stopped-flow NMR methods
Ran Wei – @RanWei_NMR
A new stopped-flow NMR apparatus was constructed to capture the fleeting information from irreversible chemical reactions at the millisecond timescale. With the aid of this technique, we are able to study short-lived intermediates, and evolving reactions that occur beyond the measurement deadtime of traditional NMR experiments (t1/2 = 45 ms).
Characterization of soil organic matter (SOM) using Solid State NMR
Nikita Rao – @raoniki96
Soil is a vital component of our ecosystem and soil organic matter (SOM) is the key to a healthy soil. We aim to improve the sensitivity, resolution and instrumentation of NMR and use the results to study the impact of various environmental and other factors on the soil.
Investigation of methyl group rotation barriers in halogen bonded cocrystals via 2H NMR using T1 time constants
Shubha Gunaga – @sgshubha_
We have studied the dynamics of methyl group rotations experimentally as well theoretically in brominated and chlorinated cocrystals of 2,3,5,6-tetramethylpyrazine. Five novel cocrystals were synthesized and characterized via single crystal and X-ray powder diffraction. 2H NMR spin-echo experiments were carried out over the temperature range of 140 K to 320 K.
Composited pulses and dynamical decoupling at zero to low-field NMR
Sven Bodenstedt – @SvenBodenstedt
We will show procedures of error-tolerant, fast and general spin control of heteronuclear spin systems in zero to low-field environments. Experimental examples include dynamical decoupling of spin decoherence pathways as well as for optimized selective rotations of different spin species.
Graphite based composites for Photocatalytic Water Splitting
Mummidivarapu Varkrishna – @VarkrishnaM
The concept of photocatalytic water splitting is revolutionary however the applications aren't so feasible to scale up. This research area has largely been dominated by the inorganic materials.However, organic ones are included every now and then. But the extent is less. The exploration and preparation of composites more based on the organic substances whereas the inorganic ones can be always supporting is a huge ocean of possibilities.And NMR is quite a powerful technique to explore it!
Protein Methyl-Side Chain Dynamics via Nanoparticle-Assisted NMR Spin Relaxation
Xinyao Xiang – @xxiang2022
The nanoparticle-assisted NMR spin relaxation (NASR) method measures the enhancement in transverse spin relaxation in the presence of slowly tumbling nanoparticles. It uncovers protein internal motions on the previously unobservable nanosecond to microsecond regime. We recently extended our NASR method to methyl-side chains using 2H or 13C spin relaxation.