New types of steroid-porphyrin conjugates derived from 20-hydroxyecdysone (20E) and 24-epibrassinolide (EBl) were synthesized. An exceptional regioselectivity in the reaction of both steroids with porphyrin boronic acids was found to give side-chain-conjugated boronic esters as sole products. UV–Vis-, fluorescence and NMR spectroscopy yielded similar data for all the studied compounds confirming the solvent driven supramolecular assembly with formation of J-aggregates. CD measurements of water diluted solutions showed a clear difference between 20E and EBl conjugates. The latter showed a strong supramolecular chirality, whereas 20E J-aggregates did not.
Design and studies of novel polyoxysterol-based porphyrin conjugates / Zhylitskaya, Ha; Zhabinskii, Vn; Litvinovskaya, Rp; Lettieri, R; Monti, Donato; Venanzi, Mariano; Khripach, V. A.; Drasar, P.. - In: STEROIDS. - ISSN 0039-128X. - 77:11(2012), pp. 1169-1175. [10.1016/j.steroids.2012.07.005]
Design and studies of novel polyoxysterol-based porphyrin conjugates
MONTI, DONATO;
2012
Abstract
New types of steroid-porphyrin conjugates derived from 20-hydroxyecdysone (20E) and 24-epibrassinolide (EBl) were synthesized. An exceptional regioselectivity in the reaction of both steroids with porphyrin boronic acids was found to give side-chain-conjugated boronic esters as sole products. UV–Vis-, fluorescence and NMR spectroscopy yielded similar data for all the studied compounds confirming the solvent driven supramolecular assembly with formation of J-aggregates. CD measurements of water diluted solutions showed a clear difference between 20E and EBl conjugates. The latter showed a strong supramolecular chirality, whereas 20E J-aggregates did not.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.