Category Archives: Our Research

These are short reports about the research activities carried out at the SeRMN.
In them we describe the work done in collaboration with research groups, to summarize communications presented at scientific meetings, to report visits and stages at other laboratories or facilities, and to comment the meetings and workshops we have attended.

PhD Thesis Defense: Metabolomics and stoichiometry adapted to the study of environmental impacts on plants. PhD Thesis by Albert Gargallo Garriga

2015-09-08Our Researchecometabolomics, HPLC-MS, metabolomics, nmr, PhD ThesisAlbert Gargallo

I am defending my PhD thesis next Thursday (September 10, 2015) at 11.30am in the Sala d´Actes “Carles Miravitlles” of the Institut de Ciències de Materials de Barcelona (ICMAB), Campus UAB. The title of my thesis is “Metabolomics and stoichiometry adapted to the study of environmental impacts on plants” and below you can find an abstract of the work. If you are interested you are very welcome.

Metabolomics has allowed significant advances in biological sciences. An increasing number of ecological studies have applied a metabolomic approach to answer ecological questions (ecometabolomics) during the last few years. The work developed throughout this PhD thesis means a further step in the field of ecometabolomics. Continue reading PhD Thesis Defense: Metabolomics and stoichiometry adapted to the study of environmental impacts on plants. PhD Thesis by Albert Gargallo Garriga →

PhD Thesis: Development and application of modern pure shift NMR techniques and improved HSQC and HSQMBC experiments

2015-07-27Methods & Applications, News from the SeRMN, Our Researchcoupling-constants, enhanced resolution, full sensitivity, HOBS, homonuclear decoupling, HSQC, HSQMBC, perfect HSQC, PhD Thesis, PIP experiments, pure in-phase signals, pure-shift NMR, residual dipolar couplings, SAPS-HSQC, sensitivity enhancementLaura

Last 16^st July 2015 I defended my PhD Thesis entitled: Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments.

The present doctoral thesis is framed within the Nuclear Magnetic Resonance (NMR) spectroscopy field, more specifically in the design of modern NMR methodologies. The research work carried out is focused on the design and application of new and modern NMR methodologies (i) to perform efficient broadband ¹H homodecoupling in 1D/2D NMR experiments and (ii) to accurately determine homo- and heteronuclear coupling constants in isotropic and anisotropic conditions through improved HSQC and HSQMBC-type experiments. The thesis is presented as a compendium ten (10) publications that have been published in several peer-reviewed international scientific journals as original research papers. Continue reading PhD Thesis: Development and application of modern pure shift NMR techniques and improved HSQC and HSQMBC experiments →

Ultra-high-resolved NMR: Analysis of complex mixtures of compounds with near-identical ¹H and ¹³C NMR spectra

2015-07-20Methods & Applications, Our Publications, Our Researchenhanced resolution, HOBS, HOBS-HSQC, HOBS-HSQC-TOCSY, HOBS-HSQMBC, homodecoupling, homonuclear decoupling, NUS, Pure shift, pure-shift NMR, spectral aliasingLaura

Title: Disentangling complex mixtures of compounds with near-identical ¹H and ¹³C NMR spectra using pure shift NMR.
Authors: L. Castañar, R. Roldán, P. Clapés, A. Virgili and T. Parella.
Reference: Chem. Eur. J., 2015, 21, 7682-7685.
DOI: 10.1002/chem.201500521

Abstract: The thorough analysis of highly complex NMR spectra using pure shift NMR experiments is described. The enhanced spectral resolution obtained from modern 2D HOBS experiments incorporating spectral aliasing in the ¹³C indirect dimension enables the distinction of similar compounds exhibiting near-identical ¹H and ¹³C NMR spectra. It is shown that a complete set of extremely small Δδ(1H) and Δδ(13C) values, even below the natural line width (1 and 5 ppb, respectively), can be simultaneously determined and assigned.

References:

“Full sensitivity and enhanced resolution in homodecoupled band-selective NMR experiments” Chem. Eur. J. 2013, 19, 17283-17286.

“Simultaneous ¹H and ¹³C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra” Chem. Commun. 2014 50, 10214-10217.

“Implementing homo- and heterodecoupling in region-selective HSQMBC experiments” J. Magn. Reson. 2014, 238, 63-69.

Pulse Programs Code for Bruker:

2D HOBS-HSQC-TOCSY

Data set Example:

Mixture

Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots

2015-06-29Our Publications, Our Researchecology, LC, metabolomics, MS, nmrAlbert Gargallo

“Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots” by Albert Gargallo-Garriga, Jordi Sardans, Míriam Pérez-Trujillo, Michal Oravec,Otmar Urban, Anke Jentsch, Juergen Kreyling, Carl Beierkuhnlein Teodor Parella and Josep Peñuelas. New Phytologist. March 2015. DOI: 10.1111/nph.13377

Plants in natural environments are increasingly being subjected to a combination of abiotic stresses, such as drought and warming, in many regions. The effects of each stress and the combination of stresses on the functioning of shoots and roots have been studied extensively, but little is known about the simultaneous metabolome responses of the different organs of the plant to different stresses acting at once. We studied the shift in metabolism and elemental composition of shoots and roots of two perennial grasses, Holcus lanatus and Alopecurus pratensis, in response to simultaneous drought and warming. Continue reading Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots →

SeRMN contributions at EUROMAR 2015 Conference

2015-06-25News from the SeRMN, NMR Events & Courses, Our ResearchEva

Some of the SeRMN staff will present our last research works at the annual meeting of the European magnetic resonance community EUROMAR 2015 Conference that will take place from 5th to 10th July in Prague, Czech Republic. Find below a summary of our contributions. Continue reading SeRMN contributions at EUROMAR 2015 Conference →

PhD Thesis by Laura Castañar: Pulse Programs and Data Set Examples

2015-05-31Methods & Applications, News from the SeRMN, NMR Events & Courses, Our Publications, Our Researchaligned-media, coupling-constants, enantiodifferentiation, enhanced resolution, full sensitivity, heteronulear coupling constants, HOBS, HOBS-HSQC, HOBS-HSQC-TOCSY, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, homonuclear decoupling, HSQC, HSQMBC, J-resolved, multi-slice selection, multiple frequency pulses, NUS, one-bond proton-carbon coupling constants, perfect HSQC, PhD Thesis, PIP experiments, proton-carbon coupling constants, proton-proton coupling constants, pure in-phase signals, Pure shift, quantitative nmr, RDCs, Relaxation times, residual dipolar couplings, resolution enhancement, SAPS-HSQC, sensitivity enhancement, sign of coupling constants, spectral aliasing, T1-relaxation, T2-relaxation, two-bonds proton-proton coupling constantsLaura

Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments

In the following links one can find Data Set Examples of each Publication presented in the Thesis Work, as well as the corresponding Pulse Program Code for Bruker. All 2D spectra have been previously phased and 2ii, 2ir, and 2ri files removed, otherwise data sets would be too big. Continue reading PhD Thesis by Laura Castañar: Pulse Programs and Data Set Examples →

Laura Castañar receives award at ENC 2015

2015-05-10News from the SeRMN, Our Researchaward, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homonuclear decouplingMiquel

Laura Castañar Award to Laura Castañar at the 56th ENC held in Asilomar from 19th to 24th April 2015. was honoured at the 56^th Experimental Nuclear Magnetic Resonance Conference (ENC) with the Ritchey Travel Award for her Ph.D. Thesis research on “Development and application of modern pure shift NMR techniques and improved HSQC/HSQMBC experiments”. The award ceremony took place at the After-Dinner Program in Asilomar Conference Center in Pacific Grove, California, USA, the 23th April, 2015.
Continue reading Laura Castañar receives award at ENC 2015 →

Review – Pure shift NMR experiments: recent developments, methods and applications

2015-05-02Methods & Applications, NMR Bibliography, Our Publications, Our Researchenantiodifferentiation, enhanced resolution, full sensitivity, heteronulear coupling constants, HOBS, HOBS-HSQC, HOBS-HSQMBC, HOBS-TOCSY, homodecoupling, homonuclear decoupling, Pure shift, Relaxation times, resolution enhancement, review, SAPS-HSQC, sensitivity enhancement, T1-relaxation, T2-relaxationLaura

“Broadband ¹H homodecoupled NMR experiments: recent developments, methods and applications” by Laura Castañar and Teodor Parella. Magnetic Resonance in Chemistry, 2015. DOI: 10.1002/mrc.4238

In recent years, a great interest in the development of new broadband ¹H homonuclear decoupled techniques providing simplified J_HH multiplet patterns has emerged again in the field of small molecule NMR. The resulting highly resolved ¹H NMR spectra display resonances as collapsed singlets, therefore minimizing signal overlap and expediting spectral analysis. This review aims at presenting the most recent advances in pure shift NMR spectroscopy, with a particular emphasis to the Zangger–Sterk experiment. Continue reading Review – Pure shift NMR experiments: recent developments, methods and applications →

Ultra high-resolution HSQC

2015-04-29Our Research, Seminarsheteronulear coupling constants, HSQC, spectral aliasingNúria

SeRMN seminar

Date: Thursday 7th May, 2015
Hour: 15:30
Location: SeRMN, Facultats de Ciències i Biociències, C2/-135
Speaker: Núria Marcó, SeRMN PhD Student

The content of our recently published article entitled “Ultra high-resolution HSQC: Application to the efficient and accurate measurement of heteronuclear coupling constants” will be explained and discussed briefly. A rapid NMR data acquisition strategy in terms of enhanced resolution per time unit for the simple and efficient determination of multiple coupling constants is described. The use of 13C spectral aliasing combined with broadband 1H homodecoupling allows accurate measurements from ultra high resolved 2D HSQC cross-peaks.

NMR-Aided Differentiation of Enantiomers: Signal Enantioresolution

2015-03-24Methods & Applications, Our Publications, Our Researchchirality, enantiodifferentiationMiriam

“NMR-Aided Differentiation of Enantiomers: Signal Enantioresolution” by Míriam Pérez-Trujillo, Teodor Parella and Lars T. Kuhn. Analytica Chimica Acta, 2015. DOI: 10.1016/j.aca.2015.02.069

NMR-aided enantiodiscrimination using chiral auxiliaries (CAs) is a recognized method for differentiating enantiomers and for measuring enantiomeric ratios (er). Up to the present, the study, optimization, and comparison of such methods have been performed based on the enantiodifferentiation of NMR signals via analysing non-equivalent chemical-shift values (ΔΔδ) of the diastereoisomeric species formed. However, a poor and non-reliable comparison of results is often obtained via the analysis of ΔΔδ exclusively. In here, the concept of enantioresolution of an individual NMR signal and its importance for NMR-aided enantiodifferentiation studies is introduced and discussed. Continue reading NMR-Aided Differentiation of Enantiomers: Signal Enantioresolution →

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