Design and mechanistic study of new photo-activated carbon monoxide
releasing molecules
Marina Russo,†
Peter Štacko,†
Lenka Štackova,†
Petr Klán†
,*
†
Department of Chemistry and RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
Carbon monoxide (CO) is an endogenous signaling molecule that controls several physiological
processes. Studies of the effects of CO have demonstrated its potential to produce a variety of
beneficial health outcomes, including anti-inflammatory, anti-bacterial effects, and
antiproliferative effects on cancer.1
To circumvent the inherent toxicity of CO, light‐activated
CO‐releasing molecules (photoCORMs) have emerged as an alternative for its administration.
A good photoCORM should be stable under ambient conditions and soluble in aerobic aqueous
environments, it should release CO using light at wavelengths that do not have the potential to
impart cellular damage.
Understanding the mechanism of CO photoreleasing is a key step for designing new derivatives
with improved properties for biological applications.
Following this approach, the detailed mechanism of the photochemically induced CO release
from 3-hydroxy-2-phenyl-benzo[g]chromen-4-one (flavonol) has been studied,2
in addition, a
more detailed structure and reactivity investigation of CO-liberating photoreactions from this
family of compounds are still in progress.
Using our knowledge from the previous studies on flavonols and cyanines,3
we envisioned
that fusing those two chromophores can lead to a novel CO-releasable hybrid system that
could serve as a general strategy for designing new classes of photoCORMs. We found that
such hybrids liberate in principle two molecules of CO in high chemical yields upon
activation with NIR light up to 820 nm and exhibit excellent uncaging cross‐sections, which
surpass the cutting edges by two orders of magnitude.4
A comprehensive mechanistic study of those chromophores will be presented in the
presentation with the aim to reveal the properties of the productive excited states and emphasize
and specify the role of oxygen in the CO production.
1
Vítek L., Gbelcová H., Muchová L., Koníčková R., Šuk J., Zadinova M., Knejzlík Z., Ahmad S., Fujisawa T.,
Ahmed A., Ruml T., Digestive and Liver Disease 2014, 46 369-375.
2
Russo M., Štacko P., Nachtigallová D., Klán P J. Org. Chem. 2020, 85, 3527-3537.
3
Štacková L., Muchová E., Russo M., Slavíček P., Štacko P., Klán P. J. Org. Chem. 2020, 85, 9776-9790.
4
Štacková L., Russo M., Muchová L., Orel V., Vítek L., Štacko P., Klán P. Chem. Eur. J. 2020, 26, 13184-
13190.