The teachings provided herein relate to site-activated binding systems that selectively increase the bioactivity of phenolic compounds at target sites. The systems can include a phenolic compound bound to a reactive oxygen species, wherein the phenolic compound and the reactive oxygen species can react at a target area in the presence of a oxidoreductase enzyme. The systems can be used, for example, as an antitoxin, an antiinflammatory, or an antimicrobial. Uses can include treatment of a gastrointestinal condition, a damaged dermal tissue, or a damaged mucosal tissue, as well as in promoting gastrointestinal health that can, for example, result in alleviating gastrointestinal discomfort or, perhaps, creating a weight gain in an animal.