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Published November 1988 | public
Journal Article

Ozone Fading of Organic Colorants: Products and Mechanism of the Reaction of Ozone with Curcumin

Abstract

The organic colorant curcumin [177-bis(4-hydroxy-3- methoxyphenyl)-l,6-heptadiene-3,bdionew]a s exposed to ozone in purified air in the dark, and the exposed samples were analyzed by mass spectrometry. The major reaction products included vanillin (4-hydroxy-3-methoxybenzaldehyde) and vanillic acid (4-hydroxy-3-methoxybenzoic acid). These products and the corresponding loss of chromophore (i.e., fading of curcumin) are consistent with a reaction mechanism involving electrophilic addition of ozone onto the olefinic bonds of curcumin. Vanillin and vanillic acid did not react with ozone under the conditions of this study.

Additional Information

© 1988 American Chemical Society. Received for review January 12, 1988. Accepted May 11, 1988. This work was supported by a contract with the Getty Conservation Institute, Marina del Rey, CA. Scott Boyce of the California Institute of Technology carried out the solvent extractions. The mass spectrometry analyses were performed by Dilip K. Sensharma and John Wells, Department of Chemistry, University of California, LOB Angeles, CA. Dixie Fiedler prepared the several versions of this manuscript, and Nancy Tomer drafted the figures.

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023