Nickel peroxide induced oxidation of canthaxanthin.
Treatment of canthaxanthin (beta,beta-carotene-4,4'-dione) (1) with nickel peroxide in dichloromethane yielded a series of cleavage products, i.e., 4-oxo-beta-ionone (2), (7E, 9E)-4-oxo-beta-apo-11-carotenal (3a), (7E, 9Z)-4-oxo-beta-apo-11-carotenal (3b), 4-oxo-beta-apo-13-carotenone (4), 4-oxo-beta-apo-14'-carotenal (5), 4-oxo-beta-apo-12'-carotenal (6), and 4-oxo-beta-apo-10'-carotenal (7). In addition, oxidized canthaxanthin derivatives, i.e., isomeric ketols all-trans-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8a), (9'Z)-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8b), and (13'Z)-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8c) were obtained together with the tentatively identified (9'Z)-canthaxanthin-20-al (9). Structure elucidation of the reaction products was achieved by mass spectrometry and two-dimensional NMR spectroscopy.
Lutz-Röder
A
A
Institut für Pharmazie und Lebensmittelchemie, Universität Erlangen-Nürnberg, Germany.
Jezussek
M
M
Winterhalter
P
P
D016644:Canthaxanthin / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008752:Methylene Chloride; D009532:Nickel; D010084:Oxidation-Reduction
D007202:Indicators and Reagents; D016644:Canthaxanthin; D008752:Methylene Chloride; D009532:Nickel; C028007:nickel monoxide