Fluorine-19 Nuclear Magnetic Shielding in Some Monofluorinated Compounds

Fluorotyrosine alkaline phosphatase from Escherichia coli: preparation, properties, and fluorine-19 nuclear magnetic resonance spectrum.

Alkaline phosphatase (EC 3.1.3.1) containing m-flurotyrosine has been prepared from E. coli grown in the presence of m-flurotyrosine. The kinetic properties of the m-fluorotyrosine enzyme measured with p-nitrophenylphosphate at pH 8.0 and dinitrophenylphosphate at pH 5.5 are essentially the same as those of normal alkaline phosphatase. However, the ability of the m-fluorotyrosine protein to ref...

Fluorine-19 nuclear magnetic resonance spectroscopic study of fluorophenylalanine- and fluorotryptophan-labeled avian egg white lysozymes.

We report the 470-MHz (11.7 T) 19F solution nuclear magnetic resonance (NMR) spectra of 2-, 3-, and 4-fluorophenylalanine incorporated into the egg white lysozymes (EC 3.2.1.17) of chicken, pheasant, and duck, as well as spectra of 4-fluorotryptophan incorporated into chicken, California valley quail, and Bob White quail and 5- and 6-fluorotryptophan-labeled chicken lysozyme. The 19F solution N...

Electric quadrupole polarizabilities of nuclear magnetic shielding in some small molecules.

Computational procedures, based on (i) the Ramsey common origin approach and (ii) the continuous transformation of the origin of the quantum mechanical current density-diamagnetic zero (CTOCD-DZ), were applied at the Hartree-Fock level to determine electric quadrupole polarizabilities of nuclear magnetic shielding for molecules in the presence of a nonuniform electric field with a uniform gradi...

Fluorine-19 Magnetic Resonance Angiography of the Mouse

PURPOSE To implement and characterize a fluorine-19 ((19)F) magnetic resonance imaging (MRI) technique and to test the hypothesis that the (19)F MRI signal in steady state after intravenous injection of a perfluoro-15-crown-5 ether (PCE) emulsion may be exploited for angiography in a pre-clinical in vivo animal study. MATERIALS AND METHODS In vitro at 9.4T, the detection limit of the PCE emul...

Calculation of Nuclear Magnetic Shielding Constants in Two Simple Systems