Dried porcini mushrooms are sources of the antioxidants glutathione (GSH) and ergothionine (ERGO) 40g. Mushrooms: A rich source of the antioxidants ergothioneine and glutathione ScienceDirect In a study, researchers found that mushrooms have high amounts of the ergothioneine and glutathione, both important antioxidants, said the senior author. The researchers also found that the amounts the two compounds L Ergothioneine: A Potential Bioactive Compound from Edible Mushrooms Springer Nature Link