Cryoprobe: a key tool for the NMR characterization of small amount of peptides

2012-04-29Our Publications19F-NMR, cryoprobe, HMBC, peptidesPau

“Fast cysteine labelling of peptides promoted by an adjacent arginine has been observed with a standard labelling agent specific for amines, N-succinimidyl 4-[18F]fluorobenzoate” Sergio Abad, Pau Nolis, Juan D. Gispert, Jan Spengler, Fernando Albericio, Santiago Rojas and José R. Herance, ChemComm, Volume 48, pages 6118-6120, April 2012. DOI: 10.1039/C2CC32095A

Fast cysteine labelling of peptides promoted by an adjacent arginine has been observed with a standard labelling agent specific for amines, N-succinimidyl 4-[18F]fluorobenzoate. HMBC experiment was the key experiment to corroborate this treat. The small amounts of some peptides herein studied required the sensitivty beneffits of a 500 MHz equipped with TCI cryprobe.

Measurement of the magnitude and the sign of small ⁿJ_CH on protonated and non-protonated carbons

2012-03-26Methods & Applications, Our PublicationsHSQMBC, IPAP, proton-carbon coupling constantsJosep

“A definitive NMR solution for the simple and accurate measurement of the magnitude and the sign of small heteronuclear coupling constants on protonated and non-protonated carbons”, by Josep Saurí, Juan Félix Espinosa and Teodor Parella; Angew. Chem. Int. Ed. (2012) DOI: 10.1002/anie.201108959

The measurement of long-range proton carbon coupling constants in natural-abundance molecules has always been a tranding topic for the NMR community. Despite the extensive number of NMR techniques that have been developed, there are still remain two unsolved problems pertaining to non-protonated carbons, namely, a) and accurate measurement of very small coupling constants (less than 2-3 Hz) , and b) the absence of a general and robust approach to determine the sign of the coupling. Continue reading Measurement of the magnitude and the sign of small ⁿJ_CH on protonated and non-protonated carbons →

HPLC-DAD-(SPE)-NMR/MS II: fundamentals and working modes

2012-03-05Methods & ApplicationsHPLC-DAD-SPE-NMR/MSMiriam

This hyphenated technique combines HPLC with three complementary detection techniques – NMR Spectroscopy, Mass Spectrometry and Diode Array Detection. It is a highly rich information source, which can be obtained by one-shot analysis.

There are three different modes of work: Flow-NMR, Stop-Flow and SPE-storage; and depending on the scientific problem one or another will be the most adequate. Continue reading HPLC-DAD-(SPE)-NMR/MS II: fundamentals and working modes →

CHIRAL METABONOMICS: Giving Metabonomics a Chiral Dimension

2012-02-20Methods & Applications, Our Publications, Our Researchchirality, enantiodifferentiation, medical research, metabolomics, pharmaceuticalMiriam

“Chiral Metabonomics: 1H NMR-Based Enantiospecific Differentiation of Metabolites in Human Urine via Direct Cosolvation with β-Cyclodextrin” Míriam Pérez-Trujillo, John C. Lindon, Teodor Parella, Hector C. Keun, Jeremy K. Nicholson and Toby J. Athersuch. Analytical Chemistry, February 2012 DOI:10.1021/ac203291d

Differences in molecular chirality remain an important issue in drug metabolism and pharmacokinetics for the pharmaceutical industry and regulatory authorities and chirality is an important feature of many endogenous metabolites. We present a 1H NMR-based method for the rapid, direct differentiation and identification of chiral drug enantiomers in human urine without pre-treatment of any kind. Continue reading CHIRAL METABONOMICS: Giving Metabonomics a Chiral Dimension →

HPLC-DAD-(SPE)-NMR/MS I: all in one technique for the analysis of mixtures

2012-02-14Methods & ApplicationsHPLC-DAD-SPE-NMR/MSMiriam

The combination of liquid chromatography with three complementary detection techniques – NMR Spectroscopy, Mass Spectrometry and Diode Array Detection, provides highly rich information in a one-shot analysis.

The possibility of a post-chromatography storage /concentration of the chromatographic peaks of interest, using a SPE (Solid Phase Extraction) system, together with the use of cool probes, increases the sensitivity of the NMR detection.

Continue reading HPLC-DAD-(SPE)-NMR/MS I: all in one technique for the analysis of mixtures →

2012 NMR Events

2012-02-05NMR Events & CoursesMiquel

This is a non-exhaustive list of NMR related events taking place in 2012:

12-13 March – Bio-NMR Meeting, Barcelona, Spain
15-20 April – 53rd ENC, Miami, FL, USA
5-11 May – 20th ISMRM Meeting & Exhibition, Melbourne, Australia
26-29 June – 11th International Conference on Magnetic Resonance in Food, Wageningen, NL
1-5 July – EUROMAR 2012, University College, Dublin, Ireland
29 July-3 August – Gordon Research Conference: In Vivo Magnetic Resonance, Waterville, ME, USA
19-24 August – 25th ICMRBS – MR in Biological Systems, Lyon, France
5-8 September – 2012 World Molecular Imaging Congress, Dublin, Ireland
4-9 September – 37th FEBS Congress, Seville, Spain
9-12 September – SMASH 2012, Providence, RI, USA
25 – 28 September – IV Ibero-American NMR Meeting, Aveiro, Portugal
4-6 October – 29th ESMRMB Congress, Lisbon, Portugal

For more thorough lists of events, check these sites:

Forthcoming MR Events at Stan’s site
Upcoming NMR Events and Conferences at Canada’s Field NMR Facility for Solids
NMR Events, MRI Events and Users’ Meetings at Bruker BioSpin web site.

HR-MAS: a key technique to study Nanoparticles

2012-01-26Our Publications31P-NMR, aromatic hydrogenation, HRMAS, ligand effect, nanoparticles, ruthenium nanoparticles, surface bound molecules characterizationPau

“Phosphine Stabilized Ruthenium Nanoparticles: the Effect of the Nature of the Ligand in Catalysis” David González-Gálvez, Pau Nolis, Karine Philippot, Bruno Chaudret and Piet W. N. M. van Leeuwen. ACS Catalysis, Volume 2, Pages 317-321, January 2012 DOI: 10.1021/cs200633k

Various ligands not forming monometallic complexes were used for Ru nanoparticle stabilization, enabling the control of size, shape and electronic properties. HRMAS NMR spectroscopy allowed us to study surface-bound molecules, evidencing ligand hydrogenation and decomposition of THF during the RuNP synthesis. Continue reading HR-MAS: a key technique to study Nanoparticles →

Myo-inositol and glycine relative content may help to grade astrocytic tumours.

2012-01-16Our Publicationspattern recognitionMiquel

Cover page of the Journal Belge de Radiologie - Belgisch Tijdschrift voor Radiologie Non-Invasive grading of astrocytic tumours from the relative contents of myo-inositol and glycine measured by in vivo MRS”, Ana Paula Candiota, Carles Majós, Margarida Julià-Sapé, Miquel Cabañas, Juan José Acebes, Àngel Moreno-Torres, John R. Griffiths, Carles Arús; Journal Belge de Radiologie – Belgisch Tijdschrift voor Radiologie, 94, 319-329 (2011). DOI: 10.5334/jbr-btr.698

MRI and MRS are established methodologies for evaluating intracranial lesions. One MR spectral feature suggested for in vivo grading of astrocytic tumours is the apparent myo-Inositol (mI) intensity (ca 3.55ppm) at short echo times, although glycine (gly) may also contribute in vivo to this resonance. Continue reading Myo-inositol and glycine relative content may help to grade astrocytic tumours. →

Neurodegeneration in NPC Mice by T₂ and DTI MRI

2011-11-22Our Publications, Our Researchanimal-model, biomarkers, DTI, mapping, MRI, neurodegenerationSilvia

“In Vivo Assessment of Neurodegeneration in Niemann-Pick Type C Mice by Quantitative T2 Mapping and Diffusion Tensor Imaging”, by John W. Totenhagen, Silvia Lope-Piedrafita, Ivan A. Borbon, Eriko S. Yoshimaru, Robert P. Erickson, and Theodore P. Trouard; Journal of Magnetic Resonance Imaging 35 (2012), 528-536. doi: 10.1002/jmri.22837

NIEMANN-PICK TYPE C (NPC) disease is a rare genetic neurodegenerative disease with no cure and few effective options for treatment. Diagnosis is most often made during childhood with symptoms progressively worsening and leading to death prior to adulthood. Continue reading Neurodegeneration in NPC Mice by T₂ and DTI MRI →

Designing hybrid foldamers

2011-10-16Our Publicationsconformational-study, foldamers, hydrogen-bonds, peptides, secondary structuresPau

“Designing hybrid foldamers: The effect on the peptide conformational bias of beta- versus alpha- and gamma-linear residues in alternation with (1R,2S)-2-aminocyclobutane-1-carboxylic acid” Sergi Celis, Esther Gorrea, Pau Nolis, Ona Illa, Rosa Maria Ortuño. Organic and Biomolecular Chemistry. Volume 10, Pages 861-868, October 2011 DOI: 10.1039/C1OB06575K

Several oligomers constructed with (1R,2S)-2-aminocyclobutane-1-carboxylic acid and glycine, beta-alanine, and gamma-amino butyric acid (GABA), respectively, joined in alternation have been synthesized and studied by means of NMR and CD experiments as well as with computational calculations. Continue reading Designing hybrid foldamers →

SeRMN – NMR Service at UAB

Research & development, training, and facility management