Structure elucidation of deoxylutein II isomers by on-line capillary high performance liquid chromatography-(1)H nuclear magnetic resonance spectroscopy.

Petra Hentschel, Marc David Grynbaum, Péter Molnár, Karsten Putzbach, Jens Rehbein, József Deli, Klaus Albert

Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.

Journal of chromatography. A 2006 Apr 21

filter terms:

Thermal and iodine-catalyzed photochemical (Z/E)-isomerization of deoxylutein II [(3R,6'R)-3-hydroxy-3',4'-didehydro-beta,gamma-carotene, anhydrolutein I] (2), the dehydration product of lutein [(3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol] (4), yielded multi-component mixtures of (Z)-isomers. By I(2)-catalyzed photoisomerization, (9Z)-2, (9'Z)-2, (13Z)-2, (13'Z)-2 and (15Z)-2 are generated as main products. In addition, this thermodynamic-equilibrium mixture contains traces of (9Z,9'Z)-2 and other (di-Z)-isomers in minor concentrations. Thirteen isomers are chromatographically separated and detected on-line by UV-vis and mass spectrometry. (all-E)-Deoxylutein II (2) and six of its (Z)-configured isomers are separated by capillary HPLC (acetone-d(6)/D(2)O = 85:15) and detected on-line by (1)H NMR spectroscopy in a microprobe. With the microprobe and the active detection volume of 1.5 microl, it is possible to perform structure elucidation with very small amounts available for various (Z)-isomers of deoxylutein II (2) in the isomerization mixture.

Citation

Petra Hentschel, Marc David Grynbaum, Péter Molnár, Karsten Putzbach, Jens Rehbein, József Deli, Klaus Albert. Structure elucidation of deoxylutein II isomers by on-line capillary high performance liquid chromatography-(1)H nuclear magnetic resonance spectroscopy. Journal of chromatography. A. 2006 Apr 21;1112(1-2):285-92