|Title||The supramolecular structure of self-assembly formed by capsanthin derivatives|
|Publication Type||Journal Article|
|Year of Publication||2002|
|Authors||Bikádi, Z, Zsila, F, Deli, J, Mády, G, Simonyi, M|
|Pagination||67 - 76|
|Keywords||Carotenoid esters, CD spectroscopy, Model of J-aggregate, Paprika carotenoids, Role of OH groups|
Carotenoids form structured self-assembly upon aqueous dilution of their organic solutions. In order to test the proposal predicting carotenoid aggregates to be organized in closely packed H-type (card-pack) manner by intermolecular hydrogen bonds, the trihydroxy derivative of capsanthin (1), (6′R)-capsanthol (2) ((all-E,3R,3′S,5′R,6′R -β,κ-carotene-3,3′,6′-triol) was acetylated to obtain all varieties of mono-, di- and triacetates and the corresponding supramolecules were studied by UV/Vis- and CD spectroscopy. It was verified that derivatives lacking hydroxyl functions at either of the end-groups form the loosely organized J-type (head-to-tail) aggregates. A model for the structure of the J-type self-assembly is proposed. Evidence was also obtained suggesting that close contacts of carotenoid molecules are not confined to hydrogen bonding.