Resolution enhancement in spectra of natural products dissolved in weakly orienting media with the help of 1H homonuclear dipolar decoupling during acquisition: application to 1H-13C dipolar couplings measurements.
In weakly orienting media such as poly-gamma-benzyl-L-glutamate (PBLG) a polymer that forms a chiral liquid crystal in organic solvents, the spectral resolution for embedded molecules is usually poor because of numerous (1)H, (1)H dipolar couplings that generally broaden proton spectra. Therefore (1)H, (13)C dipolar couplings are difficult or impossible to measure. Here, we incorporate Flip-Flop decoupling during detection into an HSQC experiment. Flip-Flop removes the (1)H, (1)H dipolar couplings and scales the chemical shifts of the protons as well as the (1)H, (13)C dipolar couplings during detection. A resolution gain by a factor 1.5-4.2 and improved signal intensity by an average factor of 1.6-1.7 have been obtained. This technique is demonstrated on (+)-menthol dissolved in a PBLG/CDCl(3) phase.
Farjon
Jonathan
J
Max Planck Institut für Biophysikalische Chemie, Abt. 030, Am Fabberg 11, 37077 Göttingen, Germany.
Bermel
Wolfgang
W
Griesinger
Christian
C
D016880:Anisotropy; D016477:Artifacts; D002247:Carbon Isotopes; D006859:Hydrogen; D000432:Methanol / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D011522:Protons; D012680:Sensitivity and Specificity; D012996:Solutions
D002247:Carbon Isotopes; D011522:Protons; D012996:Solutions; C003172:poly-gamma-benzyl-L-glutamate; D011099:Polyglutamic Acid; D006859:Hydrogen; D000432:Methanol