SMP-028 potently and concentration-dependently inhibits neutral cholesterol esterase (CEase)(IC50: 1.01 μM). On the other hand, SMP-028 inhibitS other steroidogenic enzymes is weak with IC50 values>10 μM. In particular, SMP-028 does not inhibit acid CEase and only weakly reduces the activity of CYP11A1 with IC50 values>100 μM and 49.8 μM. respectively [1]. SMP-028 at 10 μM or less does not affect the viability of male adrenal cells, female adrenal cells, testicular cells, and ovarian cells. SMP-028 at concentrations higher than 30 μM significantly reduce the viability of male adrenal cells, female adrenal cells [2].