PNMT-IN-1 (inhibitor 4) is a selective second generation inhibitor [1] of phenylethanolamine N-methyltransferase (PNMT), exhibiting a Ki value of 1.2 nM and an IC50 value of 81 nM. Additionally, it disrupts the activity of DNMT1 and DNMT3b, with IC50 values of 61 μM and 17 μM, respectively, and antagonizes the action of epinephrine.

PNMT-IN-1（抑制剂4）（0.01微摩尔，4小时）特异性抑制PNMT酶活性（IC50值为81纳摩尔），且不干扰蛋白质甲基化过程。