Fluorine as an NMR probe for structural studies of chemical and biological systems

Abstract

Applications of fluorine NMR to probe long‐range interactions in rigid organic molecules, namely cubanes, and to study structures and dynamics of proteins and other biological systems, are presented. 19F NMR parameters, especially long‐range coupling constants are shown to reveal intrinsic features of the molecules. Correlations between long‐range (more than three‐bond) couplings involving fluorine and other chemical and physico‐chemical properties of the compounds are demonstrated, and examples of unusual couplings which cannot be explained by existing theories of ‘through‐bond’ and ‘through‐space’ mechanisms are discussed. Recent applications of fluorine labeling of aromatic and aliphatic amino acids in investigating protein structures and dynamics are highlighted. The potential of using 19F NMR parameters, such as large spin–spin coupling constants observed for organic compounds, for structural analysis of biological macromolecules is outlined. Copyright © 2000 John Wiley & Sons, Ltd.

¹⁹F NMR method for the determination of quality of virgin olive oil

“…In our study, we found ethanol appeared to be at δ −108.93 ppm, the same as aliphatic alcohols, while isopropanol appeared to be at δ −109.13 ppm the same as cyclohexanol, which can well demonstrate the above inference. In conclusion, the relatively small size of the fluorine nucleus (between those of hydrogen and oxygen), a nuclear spin of 1/2, 100% natural abundance, high NMR sensitivity (83% of that of a proton) and pronounced long-range effects (Gakh et al, 2000) facilitate a clear distinction of these model compounds.…”

Notes on Synthesis of Perdeutero-5-13C,5,5,5-Trifluoroisoleucine VI56

“…Fluorine NMR spectroscopy is a powerful method for the study of both structure and dynamics of proteins and their interactions with other proteins or ligands [1][2][3][4]. Because of the ability of the 19 F lone-pair electrons to participate in non-bonded interactions with the local environment, 19 F chemical shifts are sensitive to changes in van der Waals contacts, electrostatic fields and hydrogen bonding.…”

“…This scheme is modified for perdeuteration by substitution with cyanoacetic acid-d 3 H NMR spectra were recorded on the Varian Unity Inova 600 MHz spectrometer. UV spectra were recorded using a Biochrom Libra S22 UV/Visible spectrophotometer.…”

“…Synthesis of methallylcyanide-d 7 Electrochemical trifluoromethylation of methallylcyanide-d 7 Muller chose to perform electrochemical trifluoromethylation of methallylcyanide in aqueous 90% methanol between platinum electrodes whereas we chose a later system of CH 3 helps stirring and shakes off gas bubbles. Upon entering the limiting current region increasing the applied voltage is counterproductive.…”

“…Some of this material was readily soluble in diethyl ether and CDCl 3 . That fraction that was soluble in organic solvent could be hydrolysed by dissolution in TFA followed by gradual addition of water.…”