Theonellasterone, a steroidal metabolite isolated from a Theonella sponge, protects peroxiredoxin-1 from oxidative stress reactions

Peroxiredoxin-1, a key enzyme in the cellular detoxification pathway, has been identified through a chemoproteomic approach as the main partner of theonellasterone, a marine bioactive metabolite. A combination of chemical and biochemical assays disclosed its mechanism of action at the molecular level.