Slow afterhyperpolarization (sAHP) channel blocker; reduces sAHP in hippocampal slice preparations. Displays no effect on Ca2+ currents or the time course of sAHP/sIAHP. Exhibits potent inhibition of KCNQ1 and KCNQ2, but differential effects at other KCNQs. Rescues memory retrieval in dopamine β-hydroxylase knockout mice. Purity 99%. MW (observed): 350.46