ML133 HCl是一种选择性钾离子通道抑制剂，作用于Kir2.1， IC50为1.8 μM (pH 7.4)和290 nM (pH 8.5)，对Kir1.1没有作用效果，对Kir4.1和Kir7.1具有微弱的作用活性。ML133 hydrochloride is a selective inhibitor of the Kir2 family of inward rectifier (IRK, KCNJ) potassium channels. ML133 inhibits Kir2.1 with IC50 of 1.8 μM at pH 7.4 and 290 nM at pH8.5. It exhibits little selectivity against other members of Kir2.x family channels, but has no effect on Kir1.1 (IC50 > 300 μM), and displays weak activity for Kir4.1 (76 μM) and Kir7.1 (33 μM), making ML133 the most selective small molecule inhibitor of the Kir family reported to date. It also showed modest selectivity versus hERG and a larger panel of GPCRs, ion channels and transporters. ML133 HCl is a selective potassium channel inhibitor for Kir2.1 with IC50 of 1.8 μM (pH 7.4) and 290 nM (pH 8.5), has no effect on Kir1.1 and weak activity for Kir4.1 and Kir7.1 ML133 hydrochloride is a selective inhibitor of the Kir2 family of inward rectifier (IRK, KCNJ) potassium channels. ML133 inhibits Kir2.1 with IC50 of 1.8 μM at pH 7.4 and 290 nM at pH8.5. It exhibits little selectivity against other members of Kir2.x family channels, but has no effect on Kir1.1 (IC50 > 300 μM), and displays weak activity for Kir4.1 (76 μM) and Kir7.1 (33 μM), making ML133 the most selective small molecule inhibitor of the Kir family reported to date. It also showed modest selectivity versus hERG and a larger panel of GPCRs, ion channels and transporters.