Quinine-d3 is the deuterium labeled Quinine (HY-D0143). Quinine is an alkaloid derived from the bark of the cinchona tree, acts as an anti-malaria agent. Quinine is a potassium channel inhibitor that inhibits WT mouse Slo3 (KCa5.1) channel currents evoked by voltage pulses to +100?mV with an IC50 of 169 µM[1][2].