“Several phenothiazines (methylene blue, azure A, …, and quinacrine mustard), polyphenols myricetin , epicatechin 5-gallate, gossypetin, and 2,3,4,2′,…′-pentahydroxybenzophenone), and the porphyrin ferric dehydroporphyrin IX inhibited tau filament formation with IC50 values in the low micromolar range … assessed by thioflavin S fluorescence, electron microscopy, and Sarkosyl insolubility.”