Molecular Structure of the Photo-Oxidation Product of Ellagic Acid in Solution

The photoreaction of the antioxidant ellagic acid (<b>EA</b>) elicits a drastic coloration in solution from colorless to yellow in aerated tetrahydrofuran, which appears as a new absorption band at 405 nm. Analysis of the X-ray crystal structure suggests that the photo-oxidation product of <b>EA</b> is a multiple cleavage π-structure (<b>Ox-EA</b>) that results from the interaction of <b>EA</b> with singlet oxygen followed by sequential cleavage and rearrangement steps.