Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

3-24-2009

Journal or Book Title

Journal of Physical Chemistry B

Volume

113

Issue

15

First Page

5255

Last Page

5261

DOI

10.1021/jp901234z

Abstract

The potential use of the naturally occurring yellow-orange pigment curcumin as a photodynamic therapy agent is one of the most exciting applications of this medicinal compound. Although subnanosecond spectroscopy has been used to investigate the photophysical processes of curcumin, the time resolution is insufficient to detect important and faster photoinduced processes, including solvation and excited-state intramolecular hydrogen atom transfer (ESIHT). In this study, the excited-state photophysics of curcumin is studied by means of ultrafast fluorescence upconversion spectroscopy. The results show two decay components in the excited-state kinetics with time scales of 12−20 ps and ∼100 ps in methanol and ethylene glycol. The resulting prominent isotope effect in the long component upon deuteration indicates that curcumin undergoes ESIHT in these solvents. The short component (12−20 ps) is insensitive to deuteration, and multiwavelength fluorescence upconversion results show that this decay component is due to solvation of excited-state curcumin.

Comments

Reprinted (adapted) with permission from Journal of Physical Chemistry B 113 (2009): 5255, doi: 10.1021/jp901234z. Copyright 2009 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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