Inhibitor addition: 10 µL of 10X each test compound (46 or 40) in Opti-MEM without phenol red was added to sample wells for a final assay concentration of 1 µM, and 10X DMSO in Opti-MEM without phenol red was added to the top control wells. Assay plates were mixed on an orbital shaker for 15 seconds at 300 rpm and incubated for 2 hours at 37°C and 5% CO2.