Category Archives: Our Publications

These are the scientific articles published by SeRMN personnel. Posts may contain a short description of the research work objective and relevance, in addition to the abstract of the article, the bibliographic reference, and the article DOI if available.

Ex vivo method to evaluate MRI contrast agents

2014-10-13Methods & Applications, News from the SeRMN, Our Publicationsanimal-model, biospec, contrast-agents, MRISilvia

“A new ex vivo method to evaluate the performance of candidate MRI contrast agents: a proof-of-concept study” by Candiota A.P., Acosta M., Simões R.V., Delgado-Goñi T., Lope-Piedrafita S., Irure A., Marradi M., Bomatí-Miguel O., Miguel-Sancho N., Abasolo I., Schwartz S. Jr., Santamaría J., Penadés S., Arús C. J Nanobiotechnology 2014 12:12. DOI: 10.1186/1477-3155-12-12.

A new method has been developed for selecting MRI contrast agents with better expected in vivo performance. This method requires only a very small amount of contrast agent (e.g. 5 nmols/animal, 800 times less than the quantity necessary for in vivo administration) and allows to carry out a more rationally informed candidate selection, avoiding unnecessary in vivo and toxicology tests for the ex vivo poorly performing substances, consequently reducing animal needs, material consumption and overall costs. Continue reading Ex vivo method to evaluate MRI contrast agents →

Opposite metabolic responses of shoots and roots to drought

2014-10-08Our Publications, Our ResearchLC, metabolomics, MSAlbert Gargallo

scireports “Opposite metabolic responses of shoots and roots to drought” by Albert Gargallo-Garriga, Jordi Sardans, Míriam Pérez-Trujillo, Albert Rivas-Ubach, Michal Oravec, Teodor Parella and Josep Peñuelas. Scientific reports 4, Article number: 6829, October 2014. DOI: 10.1038/srep06829

Shoots and roots are autotrophic and heterotrophic organs of plants with different physiological functions. Do they have different metabolomes? Do their metabolisms respond differently to environmental changes such as drought? We used metabolomics and elemental analyses to answer these questions. Continue reading Opposite metabolic responses of shoots and roots to drought →

Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): Implications for toxicity

2014-10-06Methods & Applications, Our Publications, Our Researchalkaloids, ecology, phytochemistry, toxicityMiriam

“Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): Implications for toxicity” by Eva Castells, Patrick P.J. Mulder and Miriam Perez-Trujillo. Phytochemistry (2014) 108:137-146. DOI: 10.1016/j.phytochem.2014.09.006

Changes in plant chemical defenses after invasion could have consequences on the invaded ecosystems by modifying the interactions between plants and herbivores and facilitating invasion success. However, no comprehensive biogeographical studies have yet determined the phenotypic levels of plant chemical defenses, as consumed by local herbivores, covering large distributional areas of a species. Continue reading Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): Implications for toxicity →

Perfect-HSQC experiments: pure in-phase spectra

2014-10-04Methods & Applications, Our Publications, Our Researchheteronulear coupling constants, HSQC, one-bond proton-carbon coupling constants, perfect HSQC, proton-proton coupling constants, pure in-phase signalsLaura

“Suppresión of phase and amplitude J_HH modulations in HSQC experiments” by Laura Castañar, Eduard Sistaré, Albert Virgili, Robert Thomas Williamson and Teodor Parella. Magnetic Resonance in Chemistry, 2014 , 53:115-119. DOI: 10.1002/mrc.4149

The amplitude and the phase of cross peaks in conventional 2D HSQC experiments are modulated by both proton–proton, J_HH, and proton–carbon, ¹J_CH, coupling constants. It is shown by spectral simulation and experimentally that J_HH interferences are suppressed in a novel perfect-HSQC pulse scheme that incorporates perfect-echo INEPT periods. Continue reading Perfect-HSQC experiments: pure in-phase spectra →

SeRMN presentations at the SMASH NMR 2014 Conference

2014-08-13News from the SeRMN, NMR Events & Courses, Our Publications, Our ResearchTeo

Some of our last research works will be presented at the annual meeting of the Small Molecule NMR Conference (SMASH) that will take place in Atlanta (USA) from 7^th to 10^th September 2014.

- Dr. Teodor Parella is a program Co-Chair.

Dr. Josep Saurí will give the talk New Methods for the Sign-Sensitive Determination of Homo- and Heteronuclear Coupling Constants in the “Analysis of Chiral Molecules and Related NMR Methods” session.

Continue reading SeRMN presentations at the SMASH NMR 2014 Conference →

Simultaneous 1H and 13C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra

2014-07-17Methods & Applications, Our Publications, Our Researchchirality, enantiodifferentiation, enhanced resolution, homodecoupling, homonuclear decoupling, HSQC, pure-shift NMR, spectral aliasingMiriam

“Simultaneous ¹H and ¹³C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra” by Miriam Pérez-Trujillo, Laura Castañar, Eva Monteagudo, Lars T. Kuhn, Pau Nolis, Albert Virgili, R. Thomas Williamson and Teodor Parella. Chemical Communications 50:10214-10217 (2014). DOI: 10.1039/C4CC04077E

NMR-aided discrimination of enantiomers using chiral solvating agents (CSAs) is a well established method of enantiodifferentiation and measurement of enantiomeric ratios (er). The analysis is traditionally performed by observing chemical shift differences (ΔΔδ) in ¹H signals by conventional 1D ¹H NMR spectra. However, low ΔΔδ values and signal overlap caused by complex multiplets lead to the lack of spectral signal dispersion that preclude a straightforward analysis. Continue reading Simultaneous 1H and 13C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra →

Pure In-Phase Heteronuclear Correlation NMR Experiments

2014-06-27Methods & Applications, Our Publications, Our Researchheteronulear coupling constants, HSQC, HSQMBC, IPAP, PIP experiments, proton-carbon coupling constants, proton-proton coupling constantsLaura

“Pure In-Phase Heteronuclear Correlation NMR Experiments ” by Laura Castañar, Josep Sauri, Robert Thomas Williamson, Albert Virgili and Teodor Parella. Angew. Chem. Int. Ed. 2014, 53, 8379-8382. DOI: 10.1002/anie.201404136

A general NMR approach to provide pure in-phase (PIP) multiplets in heteronuclear correlation experiments is described. The implementation of a z-filter efficiently suppresses any unwanted anti-phase contributions that usually distort the multiplet pattern of cross-peaks and can make their analysis difficult. Continue reading Pure In-Phase Heteronuclear Correlation NMR Experiments →

HOBS experiments to measure T₁/T₂ relaxation times in overlapped regions

2014-05-14Methods & Applications, Our Publications, Our Research, Uncategorizedband-selective, CPMG, enhanced resolution, full sensitivity, HOBS, homodecoupling, homonuclear decoupling, Inversion Recovery, PROJECT, pure-shift NMR, Relaxation times, T1-relaxation, T2-relaxationLaura

“Measurement of T₁/T₂ relaxation times in overlapped regions from homodecoupled ¹H singlet signals” by Laura Castañar, Pau Nolis, Albert Virgili and Teodor Parella. Journal of Magnetic Resonance 244 (2014) 30-35. DOI: 10.1016/j.jmr.2014.04.003

The implementation of the HOmodecoupled Band-Selective (HOBS) technique in the conventional Inversion-Recovery and CPMG-based PROJECT experiments is described. The achievement of fully homodecoupled signals allows the distinction of overlapped ¹H resonances with small chemical shift differences. It is shown that the corresponding T₁ and T₂ relaxation times can be individually measured from the resulting singlet lines using conventional exponential curve-fitting methods. Continue reading HOBS experiments to measure T₁/T₂ relaxation times in overlapped regions →

Rapid and efficient enantiodifferentiation through frequency-selective pure-shift ¹H NMR spectroscopy

2014-03-06Methods & Applications, Our Publications, Our Researchband-selective, enantiodifferentiation, enhanced resolution, full sensitivity, HOBS, homodecoupling, homonuclear decoupling, pure-shift NMRLaura

“Enantiodifferentiation through Frequency-Selective Pure-Shift ¹H Nuclear Magnetic Resonance Spectroscopy” by Laura Castañar, Míriam Pérez-Trujillo, Pau Nolis, Eva Monteagudo , Albert Virgili and Teodor Parella. ChemPhysChem,15 (2014) 854-857.

DOI: 10.1002/cphc.201301130

A frequency-selective 1D ¹H NMR experiment for the fast and sensitive determination of chemical shift differences between overlapped resonances is proposed. The resulting fully homodecoupled ¹H resonances appear as resolved 1D singlets without their typical J_HH multiplet structure. The achieved high signal dispersion is here exploited in enantiodiscrimination studies using chiral solvating agents. Continue reading Rapid and efficient enantiodifferentiation through frequency-selective pure-shift ¹H NMR spectroscopy →

Confining light metal hydrides in micro- or mesoporous scaffolds

2014-03-01Our Publications27Al-NMR, 7Li-NMR, hydrides, solid-state nmrPau

“Unusual Oxidation Behavior of Light Metal Hydride by Tetrahydrofurane Solvent Molecules Confined in Ordered
Mesoporous Carbon” Klose, M.; Lindemann, I.; Minella, C.; Pinkert, K.; Zier, M.; Giebeler, L.; Nolis, P.; Baro, M.; Oswald, S.; Gutfleisch, O.; Ehrenberg, H.; Eckert, J. Journal Of Materials Research, 2014, 29, 55-63 DOI:10.1557/jmr.2013.199

Confining light metal hydrides in micro- or mesoporous scaffolds is considered to be a promising way to overcome the existing challenges for these materials, e.g. their application in hydrogen storage. Different techniques exist which allow us to homogeneously fill pores of a host matrix with the respective hydride, thus yielding well defined composite materials. Continue reading Confining light metal hydrides in micro- or mesoporous scaffolds →

SeRMN – NMR Service at UAB

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