Selenium-Based Catalytic Scavengers for Concurrent Scavenging of H₂S and Reactive Oxygen Species

Hydrogen sulfide (H2S) is an endogenous gasotransmitter that plays important roles in redox signaling. H2S overproduction has been linked to a variety of disease states and therefore, H2S-depleting agents, such as scavengers, are needed to understand the significance of H2S-based therapy. It is known that elevated H2S can induce oxidative stress with elevated reactive oxygen species (ROS) formation, such as in H2S acute intoxication. We explored the possibility of developing catalytic scavengers to simultaneously remove H2S and ROS. Herein, we studied a series of selenium-based molecules as catalytic H2S/H2O2 scavengers. Inspired by the high reactivity of selenoxide compounds towards H2S, 14 diselenide/monoselenide compounds were tested. Several promising candidates such as S6 were identified. Their activities in buffers, as well as in plasma- and cell lysate-containing solutions were evaluated. We also studied the reaction mechanism of this scavenging process. Finally, the combination of the diselenide catalyst and photosensitizers was used to achieve light-induced H2S removal. These Se-based scavengers can be useful tools for understanding H2S/ROS regulations.