Magnetic Resonance Service

 
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NMR Unit

The staff provides advice and consultation to users in the following areas:

- Structure elucidation and Quality Control in Synthetic Chemistry by solution 1D/2D-NMR (1H, 13C, 19F, 31P, 195Pt, 11B, etc.).

- Protein complexes with low molecular weight compounds. The bound-structure of the compound can be used in Structure-based Design of improved lead compounds and ultimately drugs.

. Triple resonance experiments for protein backbone assignment (those experiments are not accessible with actual equipment).

-STD-NMR Screening of single compound or compound Libraries to identify “hits” recognized by a target protein. STD-NMR/CORCEMA-ST analyses of bound-ligand conformations.

- NMR of cells, cell extracts, and Metabolomics-by-NMR.

- Diffusion experiments and DOSY.

Some examples of spectra acquired with our equipment


Varian500 2D ROESY spectrum of Cyclosporine A using AutoX Probe.

Varian500 2D multiplicity edited gHSQC spectrum of Cyclosporine A using AutoX Probe.

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EPR UnitEPRDatabase

 

 

 

TECHNICAL

The electron paramagnetic resonance spectroscopy (EPR) or electron spin resonance (ESR) allows detecting and studying stable or transient paramagnetic species such as free radicals, some transition metal ions and defects in materials in a wide range of temperatures. Thus EPR crosses several disciplines including: chemistry, physics, biology, materials science and medical science.

The free radicals are often short-lived, but still play crucial roles in many processes such as photosynthesis, oxidation, catalysis, and polymerization reactions.

The electron paramagnetic resonance studies the interaction of a paramagnetic species with the electromagnetic radiation (microwave radiation) in the presence of an external magnetic field. It detects and measures the transition between energy levels of the two orientations of the spin-electron. The spectrometer records the net absorption energy of this transition.

An EPR spectrum can provide the following information: unequivocal detection of paramagnetic species, species identification, distinction between free radicals and paramagnetic transition metals, detection of free radicals of short half-life (spin trapping), quantified information on the 'geometric and electronic structure, etc...

Spectra can be acquired from solid powder, tissues or solutions at temperatures between 4 K and above room temperature.

Research lines and collaborations:

- Characterization of stable and persistent free radicals, poliradicals, radical cations and radical anions
- Study of dopped conducting polymers and organic magnetic materials with novel optical, electronic and magnetic properties.
- Macromolecular polyradicals as potencial applications as hosts molecules in suprastructures and porous materials
- Stable radical adducts with bipolar transport properties in glassy morphological states.
- Study of new organic materials with non-linear optical properties
- Spin trapping detecction of transient radical species (cyclopropenyl radicals)
- Radical mechanism reaction by spin trapping
- Detection of stable free radicals in merina wool fabrics
- Skin and hair detecction of UV generated radicals, and application of antioxidants and UV filters
- Reaction kinetics determination
- Study of new functionalized and strongly oxidant persistent radicals, as chemosensors of the antioxidant power of polyphenoles

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Use of spin trap method and EPR spectroscopy as the analytical tool to measure the radical scavenging activity of natural products with antioxidant properties