Ergothioneine a dietderived antioxidant with therapeutic potential Halliwell 2018 FEBS Letters Wiley Online Library Dried porcini mushrooms are sources of the antioxidants glutathione (GSH) and ergothionine (ERGO) 40g. A review on mushrooms as a versatile therapeutic agent with emphasis on its bioactive constituents for anticancer and antioxidant potential 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 The nutritional benefit of mushrooms is remarkable. For centuries, mushrooms have been legendary for their nutritional value. But it's only been recently that mushrooms have been studied and their true power revealed.