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Yvonne Madu

Born in Italy to Nigerian parents, I have spent my whole life learning about both cultures and travelling between Italy and Nigeria.

I moved into the United Kingdom to further my studies. My first degree in Pharmaceutical science, from the London Metropolitan University, provided me with the building blocks of Laboratory skills, Analytical Science and of General Chemistry. This was a platform to my decision into pusuing the AS:MIT course in the University of Warwick.

Final year project: New DNP Radical Reagents for Solid State NMR of Membrane Proteins

Dynamic Nuclear Polarization (DNP) is a technique in which a nuclear magnetic resonance is observed during simultaneous irradiation of an electron paramagnetic resonance (EPR); approximately 660-fold greater spin polarization of unpaired electron in a paramagnetically doped glass matrix is transferred to nuclei before an NMR experiment. By so doing, it brings about an enhancement of the NMR spectra.

For the DNP experiment to be performed, there are three requirements that must be satisfied: first a high frequency (140-600GHz) high power (approximately 10W) microwave source is needed to drive the continuous-wave DNP transitions associated with the second order electron-nuclear dipolar interaction; secondly, due to the relaxation times of the spin systems in the experiment, DNP experiments should be performed at low temperatures (usually ≤ 90K) and in order to obtain a high resolution spectra, the incorporation of MAS is essential. The third requirement is the presence of a paramagnetic centre that acts as a source of polarisation which is resolved by the introduction of free radical reagents.

DNP can be used in conjunction with ssNMR to analyse the structure of proteins. In this case, the DNP biradical reagent should be water soluble.

Following the Keana et al. methodology, we tried to synthesise the nitroxide biradical reagent.

Consequently, analogues were synthesised to investigate the lipophilicity of a molecule by varying the length of the chain.

Italy 2010