163163-23-3

Chromanol 293B is a blocker of slowly activating delayed-rectifier K⁺ current (I_Ks) with an IC₅₀ value of 6.89 μM in Xenopus oocytes expressing rat I_Ks channels. It is selective, having no activity at rat K_v1.1 or K_ir2.1 channels at a concentration of 30 μM. Chromanol 293B increases the rate and extent of I_Ks in guinea pig ventricular cells in a dose-dependent manner. It also inhibits cystic fibrosis transmembrane conductance regulator (CTFR) Cl^- currents (I_CTFR) with an IC₅₀ value of 19 μM in Xenopus oocytes expressing human CTFR.

Chromanol 293B has been used in the inhibition of calcium and cyclic adenosine monophosphate (cAMP)-activated potassium channels in human epithelial cell lines. Chromanol 293B has been used in patch-clamp electrophysiology studies in cardiomyocytes.

ChEBI: Chromanol 293B is a 1-benzopyran.

Chromanol 293B enantiomer is a potent inhibitor of potassium channel protein (KvLQT1). In human atrial myocytes, chromanol 293B inhibits repolarization potassium currents. Chromanol 293B improves glucose-stimulated insulin secretion (GSIS) in pancreas by modulating potassium voltage-gated channel (KCNQ1).

Blocker of the slow delayed rectifier K + current (I Ks ) (IC 50 = 1-10 μ M). Also blocks the CFTR chloride current (I CFTR ) (IC 50 = 19 μ M).

Blocker of the slow delayed rectifier K+ current via KCNQ1 channels

Room temperature

[1] H. SUESSBRICH. Specific blockade of slowly activating IsK channels by chromanols — impact on the role of IsK channels in epithelia[J]. FEBS Letters, 1996, 396 2-3: 271-275. DOI: 10.1016/0014-5793(96)01113-1
[2] SUSUMU FUJISAWA  Toshihiko I  Kyoichi Ono. Time-dependent block of the slowly activating delayed rectifier K+ current by chromanol 293B in guinea-pig ventricular cells[J]. British Journal of Pharmacology, 2009, 129 5: 1007-1013. DOI: 10.1038/sj.bjp.0703126
[3] A. BACHMANN U R U Quast. Chromanol 293B, a blocker of the slow delayed rectifier K+ current (IKs), inhibits the CFTR Cl– current[J]. Naunyn-Schmiedeberg’s archives of pharmacology, 2001, 363 1: 590-596. DOI: 10.1007/s002100100410