Chlorophyll-Derived Yellow Phyllobilins of Higher Plants as Medium-Responsive Chiral Photoswitches.

ABSTRACT: The fall colors are signs of chlorophyll breakdown, the biological process in plants that generates phyllobilins. Most of the abundant natural phyllobilins are colorless, but yellow phyllobilins (phylloxanthobilins) also occur in fall leaves. As shown here, phylloxanthobilins are unique four-stage photoswitches. Which switching mode is turned on is controlled by the molecular environment. In polar media, phylloxanthobilins are monomeric and undergo photoreversible Z/E isomerization, similar to that observed for bilirubin. Unlike bilirubin, however, the phylloxanthobilin Z isomers photodimerize in apolar solvents by regio- and stereospecific thermoreversible [2+2] cycloadditions from self-assembled hydrogen-bonded dimers. X-ray analysis revealed the first stereostructure of a phylloxanthobi

SUBMITTER: Li C 

PROVIDER: S-EPMC5248603 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature