PEABODY, MA:17 January 2019: JEOL USA has developed new methodology using the company’s ROYAL HFX Probe to offer a powerful and practical alternative for the elucidation of crucial structural information. It has particular merit in the analysis of complex pharmaceutical mixtures that contain a drug substance plus its various metabolites.
It’s a familiar challenge for pharmaceutical development scientists and now, rather than relying on chromatography to separate a mixture ahead of the analysis of selected components, this emerging new application of Nuclear Magnetic Resonance (NMR) spectroscopy looks set to streamline laboratory practice by analyzing the NMR data collected on the complete sample using a 19F filtering approach.
As many synthesized drug molecules now contain fluorine, an element rarely found in organic systems, 19F NMR affords a useful means for specific screening of complex mixtures by filtering out all molecules which do not contain fluorine.
Recently published work  by universities in the UK and Brazil, undertaken in conjunction with a major pharma company, proposes a new methodology known as SRI-FESTA. 19F to 1H polarization transfer is followed by a selective labelling of a single 1H. The experiment finishes with a TOCSY transfer to reveal all the protons which are coupled to the selected 1H.
Though powerful and highly selective, SRI-FESTA requires expert knowledge in order to choose the specific excitation points for both 19F and 1H, potentially limiting its practical application in routine pharmaceutical labs.
Now, building on this interesting experimental approach and taking advantage of the unique features of the ROYAL HFX Probe, JEOL scientists have replaced the need for selective pulses with a radically different idea – the use of broadband pulses. This may give a complex initial spectrum, however a clean result can be simply obtained by modification of the phase cycle to select the desired pathway.
Dr. Michael Frey, Analytical Instruments Product Manager, JEOL USA, Inc. commented: “This is a novel way to use isotope filtering that has never been done before, as far as we are aware. As a consequence, scientists can achieve a straightforward experiment which effectively reveals the 19F filtered 1H TOCSY in a mixture, without the need for the NMR operator to first identify and then choose sites for band-selection. I believe our novel approach has vast potential for pharmaceutical development and we’re excited to see how this technique could be used to streamline experiments.”
The ROYAL HFX Probe is the world's first liquid NMR probe with the capability to manipulate the 1H, 19F, and 13C spins simultaneously without the typical loss in performance associated with traditional NMR probes design for proton-fluorine NMR spectroscopy. It provides the flexibility to simplify spectral assignments of modern complex fluorine containing compounds, and magnetic tuning allows the Probe to achieve the highest performance for either 1H or 19F in single tune mode.
To find out more, contact your local JEOL specialist, or visit: http://bit.ly/2W075TF