title: Glycerol and glycerol carbonate as ultraviscous solvents for mixture analysis by NMR.
abstract: NMR of weakly polar analytes in an apolar ultraviscous solvent has recently been proposed for mixture analysis as a pertinent alternative to the DOSY experiment. The present article reports the first use of glycerol and glycerol carbonate as polar solvents for the NMR analysis of a model mixture of dipeptides. This work demonstrates the high potentiality of these solvents for the analysis of mixtures made of polar and potentially bioactive compounds. Medium-sized molecules slowly reorient in glycerol and glycerol carbonate under particular temperature conditions, so that solute resonances may show spin diffusion in NOESY spectra, thus opening the way to mixture analysis. Glycerol and glycerol carbonate have turned out to be ultraviscous solvents of choice for the individualization of four structurally close mixed dipeptides: Leu-Val, Leu-Tyr, Gly-Tyr and Ala-Tyr by means of 1D and 2D NOESY experiments. Selective sample excitation and signal detection were implemented to eliminate the intense proton signals of the non-deuterated solvents. Moreover, the recording of a multiplet selective 2D NOESY-TOCSY has shown that the analytical power of NMR in highly viscous solvents is not limited to the extraction of mixture component 1D subspectra but may also yield some supplementary information about atom connectivity within components.
authors.affiliation: Université de Reims Champagne-Ardenne, Institut de Chimie Moléculaire de Reims, CNRS UMR 6229, IFR 53 Biomolécules, BP 1039, 51687 Reims Cedex 02, France.
authors.forename: Pedro
authors.initials: P
authors.lastname: Lameiras
authors.forename: Leslie
authors.initials: L
authors.lastname: Boudesocque
authors.forename: Zéphirin
authors.initials: Z
authors.lastname: Mouloungui
authors.forename: Jean-Hugues
authors.initials: JH
authors.lastname: Renault
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Wieruszeski
authors.forename: Guy
authors.initials: G
authors.lastname: Lippens
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Nuzillard
mesh_terms: D002254:Carbonates / Q000737:chemistry*; D017666:Deuterium Oxide; D004058:Diffusion; D004151:Dipeptides / Q000737:chemistry; D004574:Electromagnetic Fields; D005990:Glycerol / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D014783:Viscosity
chemical_list: D002254:Carbonates; D004151:Dipeptides; D011522:Protons; D012997:Solvents; C080057:leucyltyrosine; C022013:glycyltyrosine; D017666:Deuterium Oxide; D005990:Glycerol