Sigma-Aldrich mL-SI3. ≥98% (HPLC), TRPML1/2 channel inhibitor, powder. 10 mg

Four-diastereomer racemate with a cation channel TRPML1-blocking and TRPML2-activating activity, while exhibiting much weaker TRPML3 potency

mL-SI3 is a 4-diastereomer racemate (2 cis and 2 trans isomers) with a cation channel TRPML1-blocking (IC50 = 3.1 μM/trans, 18.5 μM/cis against 5 μM mL-SA1-induced cellular calcium response) and TRPML2-activating activity (EC50 = 3.3 μM/trans, 9.4 μM/cis), while exhibiting much weaker TRPML3 potency (EC50 = 28.5 μM/trans, IC50 = 29.0 μM/cis). mL-SI3 is shown to compete against mL-SA1 for binding the same TRPML1 hydrophobic cavity. Comparing with mL-SI1 (GW405833), mL-SI3 is more potent and not agonist-dependent, effectively antagonizing against TRPML1 activation by both MK6-83 and mL-SA1.