CHEMBL5731311

Inhibition of IRAP Activity: Rat epididymal fat pads were homogenized and subjected to ultracentrifugation at 100,000×g for 30 minutes to obtain microsomes containing IRAP. The microsomes (with a total protein content of 55 μg/well) were mixed with a solvent (dimethyl sulfoxide; hereinafter, abbreviated as DMSO (final concentration: 0.1%)) or with each test compound (common ratio: 3; maximum concentration: 10 μM). AVP was then added to the solution to a final concentration of 25 μM, and the resulting solution was allowed to react for one hour at 37° C. An aqueous trifluoroacetic acid (hereinafter, abbreviated as TFA) solution was then added to the solution (final concentration: 1%) to stop the enzymatic reaction. Residual AVP was then determined by mass spectrometry (MALDI-MS). Based on the results, IC50 values (nM), i.e. concentrations required for 50% inhibition of decrease in AVP level in the solvent control group, of the individual test compounds were calculated by the Sigmoid-Emax model nonlinear regression analysis to evaluate inhibition of IRAP activity.