25494-45-5Relevant academic research and scientific papers
Preparation and (E/Z)-Isomerization of the Diastereoisomers of Violaxanthin
Molnar, Peter,Deli, Jozsef,Zsila, Ferenc,Steck, Andrea,Pfander, Hanspeter,Toth, Gyula
, p. 11 - 27 (2007/10/03)
Violaxanthin A (=(all-E,3S,5S,6R,3′S,5′S,6′ R)-5,6:5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β, β-carotene-3,3′-diol = syn,syn-violaxanthin; 5) and violaxanthin B (=(all-E,3S,5S,6R,3′S,5′R,6′S)-5,6:5′, 6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-3, 3′-diol = syn,anti-violaxanthin; 6) were prepared by epoxidation of zeaxanthin diacetate (1) with monoperphthalic acid. Violaxanthins 5 and 6 were submitted to thermal isomerization and I2-catalyzed photoisomerization. The structure of the main products, i.e., (9Z)-5, (13Z)-5, (9Z)-6, (9′Z)-6, (13Z)-6, and (13′Z)-6, was determined by their UV/VIS, CD, 1H-NMR, 13C-NMR, and mass spectra.
PREPARATION OF MONO-CIS ANTHERAXANTHINS AND DETERMINATION OF THEIR GEOMETRICAL CONFIGURATION BY (13)C-NMR SPECTRAL ANALYSIS
Molnar, P.,Radics, L.,Szabolcs, J.
, p. 477 - 486 (2007/10/02)
Using (13)C-NMR methods, the stereochemistry of eight mono-cis carotenoids obtained by stereomutation of natural (3S, 5R, 6S, 3'R)- and semisynthetic (3S, 5S, 6R, 3'R)-all-trans-antheraxanthins has been established.The carbon-13 data support our earlier p
