Effects of compounds 20, 35, 42, and 43 on reducing the AKT protein level in PC3 cells. PC3 cells were treated with DMSO or compound 20 (A), 35 (B), 42 (C), or 43 (D) at the indicated concentrations for 24 h. The T-AKT protein level was determined using western blots. The DC50 values of 20 (A) and 35 (B) were quantified from three independent biological experiments.