All posts by Eva

SeRMN contributions at ISMAR EUROMAR 2019 Conference

Some of the SeRMN staff will present our last research works at the annual meeting of the European magnetic resonance community ISMAR EUROMAR 2019 Conference that will take place from 25th to 30th August in Berlin. Find below a summary of our contributions.

Pau Nolis presents a poster entitled “Reducing experimental time using Multiple Fid Acquisition (MFA) strategy” (P341). Pau Nolis, Kumar Motiram-Corral, Miriam Pérez-Trujillo, Teodor Parella.

Speeding-up NMR molecular analysis is an important research field which has been continuously advancing since NMR early days. The relevant benefits are clear and evident: reduce the time per analysis directly reduce its cost and gaining spectrometer time to analyze new samples. Many interesting tools and concepts have been appearing in last decades. Concretely, our experience focuses on the development of new NMR experiments using TS (Time-Shared), SA (Spectral Aliasing) and MFA (Multiple Fid Acquisition). MFA strategy is an interesting strategy that allows the acquisition of different structural information in a single experiment. Basically, MFA experiments consist in the design of pulse sequence experiments which accommodate several acquisition windows per experi-ment, each registering different relevant information for the structural molecular character-ization. The methodology brings a corresponding important time benefit. Last year, we have reported several new NMR experiments designed with MFA stratey and herein we would present the most relevant achievements. The overall discussion will be mainly focused on the sensitivity gains per time unit of the presented experiments.

Eva Monteagudo presents a poster entitled “Enantiodifferentiation Study of Spiroglycol Chirality” (P306). Eva Monteagudo, Albert Virgili, Teodor Parella, Carles Jaime.

The 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane commonly named pentaspiroglycol (PSG) or spiroglycol (SPG) is a high molecular weight rigid alicy-clic diol widely used in the chemical industry. SPG has no hazardous classification, it is not mutagenic and is a safe alternative to Bisphenol A, a well-known chemical which is rising concern due to his proved endocrine disruptor activity. Moreover, some of the SPG main applications are focused on epoxy resins, liquid polyester resins, radiation curing resins and in polymer film material field. However, the spiroglycol structure, configuration and conformation have never been deeply studied. Herein, we perform for the first time a preliminary NMR and computational study of the spiroglycol structure. SPG is a highly symmetrical molecule but it should be chiral due to the presence of a chiral axis. The presence of two enantiomers was demonstrated per-forming NMR enantiodifferentiation experiments using α,α’-bis(trifluoromethyl)-9,10-an-thracenedimethanol (ABTE) as chiral solvating agent (CSA). The addition of 0.6 equivalents of ABTE allows the differentiation of several spiroglycol proton signals. The lack of resolu-tion observed in the proton spectrum can be tackled through the corresponding 13C NMR spectrum where a significant enantiodifferentiation at the spirocarbon atom was observed.In order to physically separate both enantiomers, a SPG derivatization with camphor-sulphonic acid was performed affording the corresponding diastereoisomeric ester mixture.

A New Chirally Organized Trifluoromethylanthrylmethanol Derivative and Its Application as Chiral Solvating Agent

ChemistrySelect Journal“A New Chirally Organized Trifluoromethylanthrylmethanol Derivative and Its Application as Chiral Solvating Agent” By Eva Monteagudo, Pere de March, Ángel Álvarez‐Larena and Albert Virgili. ChemistrySelect, 2017, 2, pp. 7362-7367 DOI:10.1002/slct.201701429

The synthesis and structure of 1,1′‐(((10,10’‐(1,1′‐binaphthalene)‐2,2′‐diylbis(oxy))bis(methylene))bis(anthracene‐10,9‐diyl))bis(2,2,2‐trifluoroethanol), 4, is reported. This compound owns both axial and central chirality allowing its use as a chiral solvating agent (CSA) for the enantiomeric composition determination of several mixtures of chiral aromatic alcohols and amines using NMR. The study of the resulting diastereoisomeric complexes was carried out by determining its stoichiometry and association binding constants.

Chiral Recognition by Dissolution DNP NMR Spectroscopy of 13C-Labeled DL-Methionine

“Chiral Recognition by Dissolution DNP NMR Spectroscopy of 13C-Labeled DL-Methionine” By Eva Monteagudo, Albert Virgili, Teodor Parella and Míriam Pérez-Trujillo.Anal. Chem., 2017, 89 (9), pp 4939–4944 DOI: 10.1021/acs.analchem.7b00156

A method based on d-DNP NMR spectroscopy to study chiral recognition is described for the first time. The enantiodifferentiation of a racemic metabolite in a millimolar aqueous solution using a chiral solvating agent was performed. Hyperpolarized 13C-labeled DL-methionine enantiomers were differently observed with a single-scan 13C NMR experiment, while the chiral auxiliary at thermal equilibrium remained unobserved. The method developed entails a step forward in the chiral recognition of small molecules by NMR spectroscopy, opening new possibilities in situations where the sensitivity is limited, for example, when a low concentration of analyte is available or when the measurement of an insensitive nucleus, like 13C, is required. The advantages and current limitations of the method, as well as future perspectives, are discussed.

Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA

RA.indt“Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA” by José Luis. Muñoz Gómez, Eva Monteagudo, Vega LLoveras, Teodor Parella, Jaume Veciana and José Vidal Gancedo. RSC Advances, 2016, 6, 27077. DOI: 10.1039/c6ra00635c

The synthesis of two novel BDPA-like radicals, a benzyl amino (BAm-BDPA, 7) and a cyano (CN-BDPA, 5) derivative, is reported and their behaviour as polarizing agents for fast dissolution Dynamic Nuclear Polarization (DNP) is evaluated. Continue reading Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA

A New Polarizing Agent for Dissolution-DNP

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“A Benzyl Alcohol Derivative of BDPA Radical for Fast Dissolution Dynamic Nuclear Polarization NMR Spectroscopy” by José Luis Muñoz Gómez, Eva Monteagudo, Vega Lloveras, Teodor Parella, Jaume Veciana and José Vidal Gancedo. Organic & Biomolecular Chemistry, 2015, 13:2689-2693. DOI: 10.1039/C4OB02356K

 

The synthesis, structural characterization and the successful application of a carbon centered radical derived from 1,3-bisdiphenylene-2-phenylallyl (BDPA), its benzyl alcohol derivative (BA-BDPA), as a polarizing agent for Dynamic Nuclear Polarization (DNP) are described. Continue reading A New Polarizing Agent for Dissolution-DNP

Presentations at the Joint Annual Meeting ISMRM-ESMRMB 2014

Next week several SeRMN members will present our research work at the Joint Annual meeting ISMRM-ESMRMB 2014 that will take place in Milan (Italy) from 10th to 16th May. Find below a summary of our contributions.

Joint Annual Meeting ISMRM-ESMRMB

Continue reading Presentations at the Joint Annual Meeting ISMRM-ESMRMB 2014

Poster presentation at 4th International DNP Symposium

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Find below an abstract of SeRMN contribution at 4th International DNP Symposium that will be held August 28-31, 2013, in Copenhagen (Denmak).

Enantiodiscrimination Studies by 13C DNP-NMR Spectroscopy

The determination of enantiomeric purity of drugs and/or endogenous molecules is crucial since its chirality could determine its pharmacological or biological behavior [1]. Many analytical techniques are available to determine the enantiomeric excess (ee) such as, circular dichroism, capillary electrophoresis, chromatographic techniques with chiral stationary phases, etc.; having each of them drawbacks and advantages [2]. Nuclear magnetic resonance (NMR) using a chiral solvating agent (CSA) as chiral auxiliary is an easy, fast and very powerful analytical tool that allows the measurement of ee by simple signal integration [3]. Continue reading Poster presentation at 4th International DNP Symposium