Nanosecond Laser Flash Photolysis Study of Rose Bengal

         Lucie Ludvíková^1, Peter Šebej^1, Dominik Heger^1*, Jacob Wirz^1 and Petr Klán^1*

^1Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech
   Republic and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
                                             Republic.

                                         lucielud@email.cz

Rose bengal (RB) is a well-known xanthene dye used in photodynamic therapy, textile industry and
cosmetics. [1] Here we report a detailed and complete mechanistic study involving the triplet
excited state (Figure 1) and oxidized and reduced forms of RB as short-lived intermediates. The
kinetics of these species was obtained by steady–state spectroscopic and kinetic nanosecond laser
flash photolysis using a 532 nm laser as a source of excitation. Scheme 1 summarizes the processes
that can be involved upon RB excitation. This detailed investigation is an essential step towards
understanding of its role in the photochemical tissue bonding. [2]




Figure 1. Excited triplet state of RB

Scheme 1. Photochemistry of RB

[1]           I. E. Kochevar and R. W. Redmond, Singlet Oxygen, Uv-a, and Ozone, 2000, 319, 20-28.

[2]           T. S. Johnson, A. C. O'Neill, P. M. Motarjem, C. Amann, T. Nguyen, M. A. Randolph, J.
M. Winograd,

              I. E. Kochevar and R. W. Redmond, J. Surg. Res., 2007, 143, 224-229.