Dušan Uhrín Group
Welcome to the Uhrín group at the School of Chemistry, University of Edinburgh. Our work focuses on developing new liquid-state NMR methods and their application to studies of carbohydrates, carbohydrate-protein interactions and complex mixtures like dissolved organic matter, soil and more pleasurable commodities such as Scotch whisky.
We are part of the Scottish NMR Users Group (SNUG) which brings together NMR research and facilities across Scotland. Visit the SNUG webpage to find out more.
J. Sakas and D. Uhrin
Chem. Commun., 2022, 58, 13011–13014.
We present modifications of the ADEQUATE experiment which more than double the sensitivity of carbon–carbon correlations of 13CH–13CH moieties. Additionally, these improvements can be applied without a sensitivity penalty to obtain spectra with a 13C chemical shift axis in the indirectly detected dimension, instead of a double-quantum frequency, allowing simpler interpretation of spectra. The modified experiments, which use refocussing of 1JCH couplings and 1H decoupling during JCC evolution intervals, were tested on several molecules, including a pentasaccharide (20 mg, 19 mM), where on average a 2.6-fold signal-to-noise improvement was achieved and the number of observable correlations increased. Doubling sensitivity results in a 4-fold reduction of the experimental time, allowing ADEQUATE spectra to be recorded overnight instead of over multiple days.
G. Peat, P. J. Boaler, C. L. Dickson, G. C. Lloyd-Jones and D. Uhrín
Nat. Commun., 2023, 14, 4410.
We report on a liquid-state NMR methodology that significantly increases the sensitivity of diffusion coefficient measurements of pure compounds, allowing to estimate their sizes using a much reduced amount of material. In this method, the diffusion coefficients are being measured by analysing narrow and intense singlets, which are invariant to magnetic field inhomogeneities. The singlets are obtained through signal acquisition embedded in short (<0.5 ms) spin-echo intervals separated by non-selective 180° or 90° pulses, suppressing the chemical shift evolution of resonances and their splitting due to J couplings. The achieved 10−100 sensitivity enhancement results in a 100−10000-fold time saving. Using high field cryoprobe NMR spectrometers, this makes it possible to measure a diffusion coefficient of a medium-size organic molecule in a matter of minutes with as little as a few hundred nanograms of material.