Common xanthene fluorescent dyes are visible-light activatable CO-releasing molecules
Marek Martínek, Lucie Ludvíková, Mária Šranková, Rafael Navrátil, Lucie Muchová, Jiří Huzlík, Libor Vı́tek, Petr Klán, Peter Šebej
Abstract
Fluorescein, eosin Y, and rose bengal are dyes used in clinical medicine and considered (photo-)chemically stable. Upon extensive irradiation with visible light in aqueous solutions, we found that these compounds release carbon monoxide (CO) - a bioactive gasotransmitter - in 40-100% yields along with the production of low-mass secondary photoproducts, such as phthalic and formic acids, in a multistep degradation process. Such photochemistry should be considered in applications of these dyes, and they could also be utilized as visible-light activatable CO-releasing molecules (photoCORMs) with biological implications.