Global NMR Discussion Meetings

Small molecules NMR

  • Effects of Membrane Composition on Kindlin-2 Binding to Phosphatidyl Inositol Phosphates in Lipid Bilayers

    Zainab Mustapha (Rutgers University, United States)

    Abstract: Kindlin-2, K2, is a peripheral membrane protein and co-activator of integrin signaling in the cell, which is implicated in cell migration, adhesion, and cancer. K2 contains a pleckstrin homology (PH) domain, which, like many PH domains, binds to the phosphoinositide components of the cell membrane, specifically phosphatidylinositol-3,4,5-trisphosphate (PIP3), to enhance integrin activation. However, the mechanism of PIP3 recognition and binding is not fully understood, as no structural studies to date use full-length PIP3 in lipid bilayers, focusing instead on the soluble inositol headgroup.
    In this study, we use a combination of solid-state and solution NMR to investigate the structure and dynamics of PIP3-bound K2-PH in a model membrane containing PIP3, phosphatidylcholine, phosphatidylserine, and cholesterol. We study changes in the bound state with respect to the model membrane and the unbound protein. Using proton detection and very fast MAS, ssNMR results show chemical shift perturbations in the backbone of the bound protein compared to the unbound form. These perturbations confirm interactions in areas predicted to interact with the membrane (in our MD simulations). We also describe how additional membrane components, such as cholesterol, can stabilize the binding of the protein.
    Together, these results suggest that PIP3 binding induces structural changes in membrane-interacting regions of K2-PH, and that additional membrane components may help stabilize this interaction. Our findings help explain the mechanism of K2-PH binding to PIP3s in the context of a full-length lipid bilayer, which has broad implications for the PIP-based regulation of numerous important cellular processes.

    1. Nicolas Bolik-Coulon Avatar
      Nicolas Bolik-Coulon

      Nice presentation!

      I have a few questions:
      1) Are the bilayers preserving their structural integrity upon spinning in MAS?
      2) T398 seem to split into two. Would you have an explanation for this?
      3) Can you quantify the fraction of PH bound to the bilayers?

      cheers

      Reply
    2. Zainab Mustapha Avatar
      Zainab Mustapha

      Thank you! Very good questions and observation
      1) Usually, we spin the rotors containing liposomes only at 15 kHz, because they preserve their structural integrity and give good linewidth at this MAS rate. However, the 31P 1D data of the bound sample was spun at 40 kHz and the 31P static spectra taken before and after shows that the bilayer structure is preserved. So yes, the bilayers preserve their structural integrity

      2) Very nice observation, I am still trying to make sense of all the changes we see.

      3) Yes, so we start out with solution NMR titration, which of course renders the membrane-associated protein invisible as the titration progresses. When we pellet the complex, we collect the supernatant and take 15N-HSQC to estimate how much of it is left in solution. We use this as a measure of what is bound to the bilayer.

      I hope this answers your question. Please let me know if you have any suggestions or input. I’ll be happy to take them. Thank you again.

      Reply
    3. KSHAMA SHARMA Avatar
      KSHAMA SHARMA

      Dear Zainab,
      Thank you for your presentation.

      1. I was wondering if you were able to determine the binding constants from your titration studies. If so, could you share the binding affinity you observed between the PH domain and PIP3?
      2. Looking at your static 31P spectra, I noticed slight differences between the bound and unbound forms. Could you please elaborate on what might be causing these differences?

      Thank you!

      Reply
    4. Zainab Mustapha Avatar
      Zainab Mustapha

      Hi KSHAMA,

      Very good questions.

      1. We didn’t determine binding affinity from our solution NMR titrations. However, in a pioneering work with the soluble headgroup of PIP3, the Kd was measured to be about 2.12 uM. It’s worth thinking about if the presence of the tails would give a different measurement.

      2. The presence of the protein may be inducing some sort of membrane curvature on the bound sample compared to the unbound. It can be that some of phosphates in the bilayer now have a different orientation as a result of protein binding. Overall, even though there are subtle differences between the two spectra, we think the bilayer may not be completely destroyed because at a different protein:lipid ratio (data not shown), the static spectra completely shows a different powder pattern.

      Thanks for engaging with my research and I hope this answers your questions. Happy to take any suggestions or further questions.

      Reply

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  • Identifying multiple quantum coherence in ionic liquids

    Yanan Li (New York University, United States)

    LinkedIn: @Yanan Li; X: @YananLi12451

    Abstract: Multiple-quantum NMR spectroscopy has long been employed to selectively isolate specific magnetization components. Here, we combined CRAZED and triple-quantum-filtered (TQF) experiments to investigate multiple quantum coherences in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4). This approach offers detailed insights into the ion dynamics and intermolecular interactions characteristic of ionic liquids.

    1. Kirill Sheberstov Avatar
      Kirill Sheberstov

      Hi, on slide 5, you show the dependence of the signal intensity on the angle θ. Which experimental parameters set up this angle? Another question: how many coupled spins are necessary to have to expect triple quantum coherence? And zero order coherence?

      Reply
      1. Yanan Li Avatar
        Yanan Li

        For the first question,we control the angle θ by adjusting the relative amplitudes of gradients along y and z (Gz, Gy).
        For the second question, triple quantum coherence are required at least three coupled spins (like I1+I2+I3+ or I1-I2-I3-). Zero order coherences are formed with at least 2 spins (like I1+I2- or I1-I2+).

        Reply
    2. Yunfan Qiu Avatar
      Yunfan Qiu

      Yanan,
      Thank you for your presentation. You clearly demonstrated intermolecular contributions to the quantum coherence. Since this is an ionic compound, does the contribution come from the cationic counterpart of BF₄ anion or from other ionic liquid species? Do you expect certain nuclei to contribute more significantly? Looking forward to your insights.

      Reply
    3. Yanan Li Avatar
      Yanan Li

      Thank you for the good question! I would say that the observed intermolecular quantum coherences of 11B likely originate from interactions between the BF4 anion and both neighboring anions and cations (11B-1H, 11B -19F, 11B-11B). It is difficult to draw a conclusion from the standard CRAZED experiments, but I tend to favor 1H due to its higher magnetic separation ratio and natural abundance.

      Reply

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  • UV-Induced PET Depolymerization in m-Cresol Monitored by Time-Resolved Diffusion NMR on a Benchtop Spectrometer

    Farwa Khalid (Insitute of physical chemistry, Polish Academy of Sciences, Poland)

    Abstract: PET (polyethylene terephthalate) is commonly used in bottles, fabrics, and packaging due to its transparency, durability, and mechanical properties. Its extensive use, combined with its natural degradation under sunlight and UV rays, slowly and uncontrollably contributes to environmental pollution [1]. Efforts to address waste PET face challenges in achieving energy-efficient and selective depolymerization through physical sorting or existing chemical methods[2]. The depolymerization of PET in m-cresol under UV light is key to breaking it down into valuable monomers[3].
    This study investigates UV-induced depolymerization of PET in m-cresol, focusing on real-time monitoring with Benchtop NMR. A flow-based experimental setup ensures continuous UV light exposure, while Diffusion NMR provides insights into diffusion properties and molecular size distribution during the process. Real-time diffusion data reveals the depolymerization kinetics, transitioning from high-molecular-weight polymer chains to low-molecular-weight monomers. This method offers valuable insights into the mechanistic pathway of PET depolymerization, potentially improving sustainable plastic waste management.
    References
    [1] F. Cao, L. Wang, R. Zheng, L. Guo, Y. Chen, and X. Qian, “Research and progress of chemical depolymerization of waste PET and high-value application of its depolymerization products,” Nov. 03, 2022, Royal Society of Chemistry. doi: 10.1039/d2ra06499e.
    [2] S. Zhang et al., “Selective depolymerization of PET to monomers from its waste blends and composites at ambient temperature,” Chemical Engineering Journal, vol. 470, Aug. 2023, doi: 10.1016/j.cej.2023.144032.
    [3] S. S. Karim et al., “Model analysis on effect of temperature on the solubility of recycling of Polyethylene Terephthalate (PET) plastic,” Chemosphere, vol. 307, Nov. 2022, doi: 10.1016/j.chemosphere.2022.136050.

    1. Kirill Sheberstov Avatar
      Kirill Sheberstov

      Hi Farwa, I have a question regarding the interpretation of DOSY experiments. In case of signal overlap, under which conditions is it possible to distinguish the two overlapping components? Would a signal display mono or biexponential decay? Thank you.

      Reply
    2. FARWA kHALID Avatar
      FARWA kHALID

      I have used a PGSTE-WET to suppress the solvent signals interfering with the PET peaks. Selecting a gradient strength value where the interfering signal is attenuated and only the desired signal appears. This way, I filter out the solvent peaks in the DOSY spectrum.Also, we are using Tailored fitting Normalization to get the polydispersity index.

      Reply
    3. Blake Wilson Avatar
      Blake Wilson

      Hi Farwa, great presentation. How does the wavelength of UV light influence the results you see?

      Reply
      1. Farwa khalid Avatar
        Farwa khalid

        Hi,
        The wavelength of the UV light greatly affects the photodegradation. I even tried the experiment with 270nm wavelength, but I didn’t see the degradation efficiently, even though this one has high energy, because PET shows maximum absorption closer to 300-320nm due to the aromatic ring and ester group. In 270 nm, I did not see the degradation product (Monomer) peak in the region around 9ppm, as it is shown in 365nm proton NMR spectra in my presentation and also I have calculated the peak area of the polymer peak its almost constant in 270nm.

        Reply

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  • Identification, Quantification, and Isolation of Synthetic Cannabinoids in Forensic Drug Seizures

    Mariana Riccio (Universidade de Brasília, Brasil)

    Abstract: Synthetic cannabinoids represent one of the most diverse classes of emerging psychoactive substances and are frequently seized in forensic operations. These substances, designed to mimic the effects of Δ9-tetrahydrocannabinol (Δ9-THC), exhibit diverse chemical structures, making their identification and quantification challenging using conventional methods. In this context, Nuclear Magnetic Resonance (NMR) spectroscopy has emerged as an advantageous analytical alternative, enabling structural characterization and accurate quantification without the need for commercial reference standards of the analyte itself. This study aimed to identify, quantify, and isolate the synthetic cannabinoids JWH-073, JWH-210, and JWH-250 from samples of plant material seized by the Brazilian Federal Police. For this purpose, gas chromatography-mass spectrometry (GC/MS) was used for the preliminary identification of cannabinoids in the samples, flash chromatography for separation, and NMR spectroscopy for characterization and quantification. The results obtained through NMR allowed for detailed structural characterization and confirmation of the identity of the cannabinoids JWH-073, JWH-210, and JWH-250, whose concentrations in the seized samples were 1.42%, 1.64%, and 0.87% (w/w), respectively. Additionally, purification via flash chromatography enabled the separation of the compounds with purities of 76.1% for JWH-073, 72.7% for JWH-210, and 89.0% for JWH-250. The data obtained demonstrate the efficiency of NMR as an analytical method for the quantification of synthetic cannabinoids, providing a reliable approach for forensic analysis without the need for commercial reference standards.

    1. Chloé Gioiosa Avatar
      Chloé Gioiosa

      Hello Mariana, thank you for the nice presentation!
      I have two questions :
      1. At which magnetic field and with what range of concentration did you do your analysis of the mixture with?
      2. I was wondering if this methodology could be used in the future to discriminate the origin of the seized material based on their cannabinoid composition?

      Reply
      1. Mariana Riccio Avatar
        Mariana Riccio

        Hello! Thank you so much for your kind feedback and for your thoughtful questions!

        1. Magnetic field and concentration range:
        The NMR analyses were performed on a 14.1 T spectrometer (600 MHz for ¹H NMR). For the preparation of the samples, 100 mg of plant material was extracted with 1 mL of CDCl₃, resulting in a crude extract that was directly analyzed. The cannabinoid concentrations within this extract ranged from 1 to 3 mg/mL.

        2. Discriminating the origin of the seized material:
        In an ideal scenario, yes — the cannabinoid composition could potentially be used to discriminate the origin of seized material, but it’d have to be supported by a comprehensive database and chemometric tools.

        In Brazil, for instance, the Federal Police runs a project called PeQui (Perfil Químico das Drogas), which focuses on establishing standardized chemical profiles of seized drugs to support forensic intelligence. This includes the analysis of purity, minor constituents, adulterants, and solvent residues to help identify trafficking routes, distribution patterns, and — when possible — infer geographic origin.

        Reply
        1. Chloé Gioiosa Avatar
          Chloé Gioiosa

          Thank you for your answers!

          Reply
    2. Cory Widdifield Avatar
      Cory Widdifield

      Hello,

      I assume that these samples provided by the police were initially as plants (or plant parts). Could you describe the workup stages (extractions?) that are required to isolate the relevant compounds from the plant? Also, I think you are showing 1H NMR results only. Would adding 13C NMR data be useful to help increase your confidence in assigning the spectra to chemical compounds in the samples?

      Reply
      1. Mariana Riccio Avatar
        Mariana Riccio

        Hello, Cory! Thank you for your interest.

        Yes, the samples provided by the Federal Police were plant materials — specifically herbal mixtures suspected to contain synthetic cannabinoids. Here’s a description of the extraction and isolation process for the enriched samples:

        Extraction and isolation:
        A total of 3.85 g of plant material, previously confirmed by GC/MS to contain a mixture of three synthetic cannabinoids, was extracted with 25 mL of methanol in a Falcon tube. The mixture was vortexed for 5 minutes, sonicated for 1 hour, and then centrifuged. The supernatant was collected, and the whole process was repeated another time under the same conditions. The combined extracts were evaporated at room temperature, yielding 165 mg of dry extract.

        This extract was then subjected to flash chromatography using a Biotage® Isolera One system, with a 10 g normal-phase silica column (25–33 µm). The elution was performed with an hexane/ethyl acetate mixture (95:5), allowing the isolation of enriched fractions of the cannabinoids for further analysis.

        Regarding ¹³C NMR:
        You’re absolutely right — while ¹³C NMR would certainly improve the confidence in compound identification, it was only feasible for the enriched fractions obtained through chromatography. In the crude extract, the analyte concentration was too low (~0.5-2%), and acquiring reliable ¹³C spectra would require prohibitively long acquisition times due to sensitivity limitations.

        Reply
        1. Cory Widdifield Avatar
          Cory Widdifield

          Thank you for your responses.

          Reply
    3. Yunfan Qiu Avatar
      Yunfan Qiu

      Hi Mariana,
      Thank you for your presentation, and I enjoyed it! I have two questions: 1. Have you tried using 2D NMR to further validate the structures of the different isomers? 2. This may not be directly related to the NMR focus of this conference, but have you considered getting crystals to precisely determine the structures? look forward to your thoughts.

      Reply
      1. Mariana Riccio Avatar
        Mariana Riccio

        Hi Yunfan,
        Thank you for your kind words and thoughtful questions!

        1. Regarding the use of 2D NMR: yes, we employed 2D experiments—specifically COSY, HSQC, and HMBC—to support the assignment of chemical shifts and confirm the substitution pattern of the isomers. These correlations were essential to distinguish between JWH-250 and its positional isomer JWH-201.

        2. As for crystallography: although single-crystal X-ray diffraction would certainly provide definitive structural confirmation, we didn’t pursue it in this project. The combination of GC/MS and 1D/2D NMR already provided sufficient information to identify the structures with confidence. Moreover, growing suitable crystals from the isolated fractions would have been particularly challenging, both because of the small amount of material and the need for pure, well-formed single crystals. So considering the analytical goals and the limited sample availability, we prioritized solution-state NMR techniques.

        Best regards,
        Mariana

        Reply

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  • Long-lived states that can survive a phase transition!

    Vishal Varma (Indian Institute of Science Education and Research (IISER) Pune, India)

    Abstract: In NMR spectroscopy, the longitudinal relaxation that destroys both classical and quantum information by restoring the spin populations to thermal equilibrium has traditionally hindered our ability to harness the full potential of spin dynamics. However, the emergence of long-lived states (LLS) has challenged this notion. With lifetimes significantly exceeding the spin-lattice relaxation time constant T1, LLS has revolutionized the field, enabling advanced medical imaging, chemical analysis, and quantum information processing applications.

    While LLS has predominantly been observed in isotropic phases, its presence in anisotropic phases has remained an intriguing question. I will show that LLS can be prepared in a two-spin system oriented in a liquid crystal solvent and, even more strikingly, demonstrate that it can survive the phase transition from the oriented phase to the isotropic phase when subjected to heating. This resilience highlights the untapped potential of LLS in various applications.

    Reference(s):

    V. Varma and T. S. Mahesh, “Long-Lived Singlet State in an Oriented Phase and its Survival across the Phase Transition Into an Isotropic Phase,” Phys. Rev. Applied 20, 034030 (2023).

    1. Kirill Sheberstov Avatar
      Kirill Sheberstov

      Why do you use M2S in the partially oriented phase and smth like the Sarkar sequence in the isotropic phase? How long does it take for the phase transition to occur, and how does this time compare to the lifetime(s) of LLS in the oriented phase and in the isotropic phases?

      Reply
    2. Vishal Varma Avatar
      Vishal Varma

      Hi Kirill Sheberstov. The spins are strongly coupled in the partially oriented phase; therefore, we use the M2S sequence. We use the Sarkar sequence in the isotropic phase due to weak coupling between the two spins.

      The phase transition takes less than 30 seconds. We turn on the probe heater 10 seconds before the M2S, because it takes a few seconds before a significant temperature rise is observed. The rest of the time is spent during storage when the WALTZ-16 sequence is applied.

      Near the transition temperature, the LLS lifetime is 4.6 seconds (in oriented phase) and above 8 seconds (in isotropic phase). So we give minimum 16 seconds of storage time before acquiring the signal with the Sarkar sequence in isotropic phase. This delay is above 5*T_lls for both the oriented and isotropic phases.

      Thanks for your interest.

      Reply
    3. Cory Widdifield Avatar
      Cory Widdifield

      Hello, this presentation appears to be from the viewpoint that survival of the long-lived singlet (LLS) state would be unexpected upon a phase transition. Could you clarify why undergoing a phase transition might eliminate all the coherent signal associated with the LLS state? Did your understanding change as a result of making these experimental measurements? Are you able to comment on whether there is a ‘scaling’ in the amount of LLS coherence when undergoing the phase transition (for example, is some portion irreversibly lost, or does it appear to be quantitatively ‘all there’ after accounting for otherwise ‘normal’ relaxation processes that would occur during the time associated with the phase transition)?

      Reply
      1. Vishal Varma Avatar
        Vishal Varma

        Hello. Thank you for your questions.

        As the phase transition happens, the structure of the Hamiltonian changes. The residual dipolar coupling is decreasing with the temperature, and we were unsure whether the LLS would survive this change! We found that the LLS survives this, and we verified that the signal observed in the isotropic phase originates from the LLS coherence prepared in the oriented phase.

        Regarding the question of scaling in the amount of LLS coherence, I think some part is irreversibly lost because the heating of the sample is non-uniform. Some parts of the sample might not have been entirely converted to the liquid phase, making it a mixed phase. Moreover, since the detection sequence in the isotropic phase is designed to detect the LLS coherence in the isotropic phase, it might also be that some LLS coherence was not observed.

        I appreciate your questions. Please let me know if my answer is unclear or if I have misunderstood the question. I would be happy to discuss. Thanks again.

        Reply
        1. Cory Widdifield Avatar
          Cory Widdifield

          Thank you for your responses.

          Reply

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  • Fibrosis Under the Lens: NMR Metabolomics and Machine Learning Illuminate Hidden Pathways and Offer a Non-Invasive Alternative to Liver Biopsy”

    Shreya Pandey (Centre of Biomedical Research, India)

    LinkedIn: Shreya Pandey; X: @shreyapandey171

    Abstract: The landscape of chronic liver disease has changed significantly, with metabolic dysfunction-associated steatotic liver disease(MASLD) now emerging as the most widespread form worldwide. In Asia, particularly in India, the prevalence of MASLD is increasing, largely driven by poor dietary habits and a sedentary way of life. MASLD spans from fat deposition to inflammation and fibrosis. Fibrosis stands out as the most critical indicator of liver-related complications and overall risk of death in MASLD. Early identification of fibrosis is critical, but current tests are often invasive or unreliable. While studies have explored metabolic changes in MASLD, few have focused on distinguishing early-stage fibrosis from steatosis.
    In this study, we used NMR-based metabolomics to analyse serum samples from n = 103 MASLD patients, divided into fibrosis (n = 44) and non-fibrosis (n = 59) groups based on standard non-invasive scoring systems. We identified seven metabolites—arginine, glycerol, aspartate, glucose, phenylalanine, histidine, and citrate—that significantly differed between the two groups and showed good diagnostic potential (AUROC> 0.70). Pathway analysis revealed disruptions in arginine and nitrogen metabolism, associated with liver scarring processes, and in energy and lipid metabolism, pointing to mitochondrial dysfunction and lipotoxic stress. Reduced aspartate levels also suggested loss of natural protection against fibrosis.
    This is the first study of MASLD cohort to differentiate early-stage fibrosis from steatosis using metabolomics. Our findings highlight the potential of a simple NMR based blood test to aid early diagnosis, guide treatment decisions, and personalize care—offering a non-invasive alternative to improve MASLD management.

    1. Chandan Singh Avatar
      Chandan Singh

      Thanks for the nice presentation. I have following questions related to the presentation:

      1. As per the study enhanced level of arginine leads to increased proline synthesis. Is this enhanced proline level reflected in metabolic profile?
      2. How is the lipid profile? Are there specific lipids which are changing?
      3. How does enhanced level of collagen synthesis lead to fibrosis?
      4. What portion of the result was used in machine learning?

      Thanks again

      Reply
      1. Shreya Pandey Avatar
        Shreya Pandey

        Thank you sir.
        1- Yes sir, even the proline level was enhanced in the NMR profiling , however it didnot match the criteria to be considered as significant metabolite ( despite having p value 1 , the AUC value was 0.65 so we had to exclude it).
        2- The few lipids that we obtained using diffusion edited pulse program also profile had significant difference. -CO-CH2-CH2- (corresponding to cholesterol and FA{TAG and Phospholipids}) was found to be increased in fibrotic cohort, similarly PUFA was found to be decreased in fibrotic cohort. As we did using NMR we have limited data corresponding to lipids. Once we use LC we might get broader insights which we will be starting soon
        3- When there is continuous injury or inflammation to liver , Hepatic stellate cells gets activated due to cascade of events. These HSCs are major contributers for collagen. When the level of collagen increases , it starts accumulating in the liver , distorting the normal structure and function and liver and eventually forming scarred tissue. This condition is called fibrosis.
        4- Only the data from bins of significant metabolites was used. We excluded the water region and the regions that were not significant

        Reply
    2. Chandan Singh Avatar
      Chandan Singh

      Thanks for a nice presentation. I have following questions:

      1. As shown in the presentation the enhanced level of arginine leads to increased collagen production via increased proline level. Is increased proline reflected in the NMR profiling?
      2. How is does lipid profile look? Any specific lipids which are enhanced?
      3. How does increased collagen lead to liver fibrosis?
      4. What exact data was used in machine learning?

      Thanks again

      Reply
      1. Shreya Pandey Avatar
        Shreya Pandey

        Thank you sir.
        1- Yes sir, even the proline level was enhanced in the NMR profiling , however it didnot match the criteria to be considered as significant metabolite ( despite having p value 1 , the AUC value was 0.65 so we had to exclude it).
        2- The few lipids that we obtained using diffusion edited pulse program also profile had significant difference. -CO-CH2-CH2- (corresponding to cholesterol and FA{TAG and Phospholipids}) was found to be increased in fibrotic cohort, similarly PUFA was found to be decreased in fibrotic cohort. As we did using NMR we have limited data corresponding to lipids. Once we use LC we might get broader insights which we will be starting soon
        3- When there is continuous injury or inflammation to liver , Hepatic stellate cells gets activated due to cascade of events. These HSCs are major contributers for collagen. When the level of collagen increases , it starts accumulating in the liver , distorting the normal structure and function and liver and eventually forming scarred tissue. This condition is called fibrosis.
        4- Sir, the data from the binned sheet that we obtained from chenomx was used in machine learning learning.

        Reply
    3. Daniel Vincent Avatar
      Daniel Vincent

      Interesting work! Could you tell the pulse program used? What data did you use for building the model ? Is NMETA available online

      Reply
      1. Shreya Pandey Avatar
        Shreya Pandey

        Thank you Daniel, we have used CPMG pulse program which is basically used to suppress large molecules. We have used the binned sheet generated using chenomx for creating model. As far as NMETA is concerned, it is not available online we are still working on it.

        Reply
    4. Ch s karthik Avatar
      Ch s karthik

      The presentation looks very informative but can you answer me the following question: What is NMeta? What all information does it require?

      Reply
      1. Shreya Pandey Avatar
        Shreya Pandey

        Thank you, Karthik,
        NMETA is a web-based application we are currently working on as part of our effort to develop a non-invasive alternative to liver biopsy.
        The process is simple: perform a 1D NMR experiment on a serum sample and upload the resulting spectrum to our webpage. The tool will then provide the probability of the individual having liver fibrosis.

        Reply
    5. Marco Schiavina Avatar
      Marco Schiavina

      Hello Shreya!
      Interesting work, I was wondering how did you handle the large lipo protein signals arising from the blood samples. Did you filter them out? Is there any evidence of these proteins to be a biomarker of the disease?

      Reply
      1. Shreya Pandey Avatar
        Shreya Pandey

        Thank you, Dr. Schiavina,
        We have not filtered the serum as we had to perform diffusion edited experiment on the same serum sample. Instead, we have used the CPMG pulse sequence to suppress signals from large molecules, particularly lipoproteins and lipid fragments, thereby minimizing their interference.
        While previous studies have compared MASLD (formerly NAFLD) with hepatocellular carcinoma (reference: ref:-https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(21)00455-2/fulltext), none have specifically examined non-fibrotic MASH versus early fibrotic MASH within the MASLD cohort. We are currently investigating this comparison and expect to share promising results soon.

        Reply

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  • Characterization of Flufenamic Acid Spatial Structure in scCO2 Based on 2D NOESY Data

    Valentina Sobornova – @VSobornova7121

    We analyzed the conformational equilibria of flufenamic acid in various media using 2D NOESY spectroscopy and quantum chemical calculations. Our results demonstrate that supercritical carbon dioxide (scCO2) is an effective medium for altering and controlling the conformational preferences of slightly soluble compounds.

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  • The Influence of Lidocaine Dimer Formation on Conformational Distribution: Insights from Quantum Chemistry and NMR

    Konstantin Belov – @Konstantin94484

    In our study, we investigated the conformer distributions of lidocaine under various isobaric and isothermal conditions. Utilizing quantum chemical calculations and NOESY spectroscopy, we found that trans-conformers, stabilized by intramolecular hydrogen bonds, predominate under specific conditions. These findings significantly influence the formation of lidocaine dimers.

  • NORD-NOESY modified NMR of Deep Eutectic Solvents

    Kelsey Marr – @kelsey_marr

    Deep eutectic solvents (DES) are low-cost, no-waste mixtures made of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD). One of the most common DES is ethaline, 1:2 choline chloride to ethylene glycol. The aim of this work is to fully elucidate the hydrogen bond network structure by 2D NMR, specifically through Nuclear Overhauser spectroscopy (NOESY). Previous attempts for ethaline have been hindered by multiple effects, one of the most prominent being radiation dampening. We have successfully utilized a NO Radiation Dampening (NORD) pulse sequence modification to the NOESY sequence and obtained build up curves of NOE and of chemical exchange.

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  • 6JFH coupling in the conformational analysis of fluorinated drugs

    Cassia Chiari – @CassiaChiari

    The forefront treatment of onychomycosis is topical therapy, however, there is a gap of knowledge on the conformational behaviour of these drugs in solution. Therefore, the present work aimed to investigate and compare efinaconazole (topical therapy) and voriconazole (oral therapy) using NMR and theoretical calculations in CDCl3, DMSO-d6 and D2O.

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