19F nuclear magnetic resonance

Part I. The 19F Nuclear Magnetic Resonance and Vibrational Spectra of Hexafluoro-metallates of Groups IVA and IVB. J. Chem. Soc. A, 1967, 698. 

J. P. Vialaneix, M. C. Malet-Martino, J. S. Hoffman, J. Pris, R. Martino, Direct Detection of New Flucytosine Metabolites in Human Biofluids by 19F Nuclear Magnetic Resonance , Drug Metab. Dispos. 1987, 15, 718-724. 

V. PROBE OF CONFORMATION OF POLYETHYLENIMINES WITH 19F NUCLEAR MAGNETIC RESONANCE... 

In view of the marked kinetic effects described so far, it has seemed wise to carry out some examination of the three-dimensional disposition of the groups on the polyethylenimines. It has been our hope that even a rudimentary insight into the conformation of the polymer would provide a guide to the search for other types of chemical reaction that might be facilitated in the presence of these polymers. The results of investigations with two conformational probes, 19F nuclear magnetic resonance and excimer fluorescence, are described. 

Fullerenes can be derivatized by various means. For example, reaction with fluorine gas proceeds stepwise to the formation of colorless CeoFeo, which, according to the 19F nuclear magnetic resonance (NMR) spectrum, contains just one type of F site and so evidently retains a high degree of symmetry.9 In view of the low adhesion typical of fluorocarbons, this spherical molecule is expected to have extraordinary lubricant properties. Curiously, bromination of Ceo is reversible on heating otherwise, the reactions of fullerenes resemble those of alkenes or arenes (aromatic hydrocarbons). 

Male Fischer 344 rats were exposed by inhalation to 1% 2-chloro-1,1,1 -trifluoroethane for 2 h and then urine was collected for 24 h. Urinary metabolites identified by 19F nuclear magnetic resonance and gas chromatography/mass spectrometry were 2,2,2-trifluoroethyl glucuronide (16%), trifluoroacetic acid (14%), trifluoroacetaldehyde hydrate (26%), trifluoroacetaldehyde-urea adduct (40%) and inorganic fluoride (3%). A minor, unidentified metabolite was also detected. No covalent binding of fluorine-containing metabolites was observed in the liver and kidney from the exposed rats (Yin et al., 1995). In-vitro incubation of 2-chloro-1,1,1-trifluoroethane with rat liver microsomes and an NADPH-generating system has been shown to involve a dechlorination reaction (Salmon et al., 1981) that produced trifluoroacetaldehyde hydrate as the only metabolite (Yin et al., 1995). 

Taylor, P. W., Feeney, J., and Burgen, A. S. V. Investigation of the mechanism of ligand binding with cobalt (II) human carbonic anhydrase by lH and 19F nuclear magnetic resonance spectroscopy. Biochemistry JO, 3866-3875 (1971). 

Simpson, M. J., Simpson, A. J., Gross, D., Spraul, M., and Kingery, W. L. (2007b). ll and 19F nuclear magnetic resonance microimaging of water and chemical distribution in soil columns. Environ. Toxicol. Chem. 26,1340-1348. 

Aksnes, D.W., Hutchison, S.M. and Packer, K.J. (1968) Nuclear spin relaxation and chemical exchange effects in the 19F nuclear magnetic resonance spectrum of the hexafluoroniobate ion. Mol. Phys., 14, 301-309. 

Taylor, J. Deutsch, C. (1988). 19F-nuclear magnetic resonance Measurements of [02] and pH in biological systems. Biophys. J. 53,227-233. 

Ulrich, A. S., Wadhwani, P., Durr, U. H. N., el al. (2006) Sohd-state 19F-nuclear magnetic resonance analysis of membrane-active peptides, in NMR Spectroscopy of Biological Solids (ed. A. Ramamoorthy), CRC Press, Boca Raton, FL, pp. 215-236. 

Lian, C., Le, H., Montez, B., Patterson, J., et al. (1994) 19F nuclear magnetic resonance spectroscopic study of fluorophenylalanine- and fluorotryptophan-labeled avian egg white lysozymes. Biochemistry, 33, 5238-5245. 

Ahvazi, B.C., C. Crestini, and D.S. Argyropoulos. 1999. 19F nuclear magnetic resonance spectroscopy for the quantitative detection and classification of carbonyl groups in lignin. J. Agric. Food Chem. 47 190-201. 

Boersma, M.G., T.Y. Dinarieva, W.J. Middelhoven, W.J.H. van Berkel, J. Doran, J. Vervoort, and I.M.-C.M. Rietjens. 1998. 19F nuclear magnetic resonance as a tool to investigate microbial degradation of fluorophanols to fluorocatechols and fluoromuconates. Appl. Environ. Microbiol. 64 1256-1263. 

Parisot, D., M.C. Malet-Martino, P. Crasnier, and R. Martino. 1989.19F nuclear magnetic resonance analysis of 5-fluorouracil metabolism in wild-type and 5-fluo-rouracil-resistant Nectria haematococca. Appl. Environ. Microbiol. 55 2474—2479. 

The theory that volatile anesthetics may act by specific binding to lipoprotein components of nerve tissue membranes or of the membrane itself has some experimental evidence. The use of 19F nuclear magnetic resonance spectroscopy with halothane indicated that saturable anesthetic sites for halothane exist in living rats at 2.5% inspired gas. The authors consider this to support the idea that volatile anesthetics do act specifically even stereospecifically (Moody etal., 1994). 

Susan, EB, HC John, FL Stephen and R Daniel (1991). Coghlan and Christopher J. Easton. Chiral molecular recognition A 19F nuclear magnetic resonance study of the diastereoisomer inclusion complexes formed between fluorinated amino acid derivatives and a-cyclodextrin in aqueous solution. Journal of the Chemical Society, Faraday Transactions, 87,2699-2703. 

Orhan H, Commandeur JN, Sahin G, Aypar U, Sahin A, Venneulen NP. Use of 19F-nuclear magnetic resonance and gas chromatography-electron capture detection in the quantitative analysis of fluorine-containing metabohtes in urine of sevoflurane-anaesthetized patients. Xenobiotica 2004 34 301 316. 

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