slo3

Quinine is a natural cinchona alkaloid that has been used for centuries in the prevention and therapy of malaria. Quinine is also used for idiopathic muscle cramps. Quinine therapy has been associated with rare instances of hypersensitivity reactions which can be accompanied by hepatitis and mild jaundice.

VU6032735 is a potent and subtype-selective inhibitor of the sperm-specific potassium channel 3 (SLO3), with IC50 values of 165 nM for human SLO3 (hSLO3) and 730 nM for mouse SLO3 (mSLO3). It also inhibits sodium channels and L-type calcium channels. VU6032735 maintains high tissue exposure in the oviduct post-fertilization and is used in contraceptive research.

Quinine hemisulfate hydrate is an alkaloid extracted from the bark of cinchona, which has antimalarial effect. Quinine hemisulfate hydrate can be used as a potassium ion channel inhibitor to inhibit the voltage-induced mSlo3(KCa5.1) channel current, and its IC₅₀ is 169 μM under the condition of +100 mV.

RU1968 bis-TFA salt is an inhibitor of the sperm-specific Ca2+ channel CatSper, thereby inhibiting human Slo3 with about 15-fold lower potency than CatSper.

VU 0546110, a selective inhibitor of the sperm-specific potassium channel SLO3 (IC50= 64 μM), demonstrates 40-fold selectivity over SLO1. It effectively blocks both heterologous SLO3 currents and endogenous K+ currents, inhibiting sperm hyperpolarization and preventing hyperactivated mobility.