rings present in both compounds were found to form two hydrogen bonds with backbone residues Glu1938 and Leu1940 in the hinge region of PIKfyve, while the indole amines were positioned in a solvent-exposed region of the binding site. Docking models also indicated that the thioether group on the alkyne terminus of 40 inserts into a hydrophobic region of the binding pocket, and the benzene ring of 46 engages in a 𝜋-𝜋 stacking interaction with Tyr2037.