Thermodynamic solubility assay.

Stocks (15 mM) of the compounds were prepared in DMSO. Each stock solution was dispensed into a 96-well plate and evaporated overnight under reduced pressure with heat (50°C). To the evaporated film/solid, 125 μl of DMEM was added to make a 2 mM solution of the target compound. This solution was sonicated for 1 h and then shaken at 37°C for 16 h. The turbid solution was passed over a 0.7-μm glass-fiber filter. The solution was diluted 1:4 in acetonitrile. The solution was centrifuged at 1,000 × g for 10 min. The supernatant (10 μl) was injected onto a Thermo Fisher Orbitrap Velos Pro instrument. A 10 μM standard was used for comparison, and the assay was done in triplicate.