– (1S,2S)-ML-SI3, the trans-isomer of ML-SI3, acts as a TRPML inhibitor. This (-)-isomer effectively inhibits TRPML1 and TRPML2 with IC 50 values of 1.6 μM and 2.3 μM, respectively, and exhibits weaker inhibition of TRPML3 with an IC 50 of 12.5 μM. In contrast, the (+)-enantiomer inhibits TRPML1 (IC 50 = 5.9 μM) and serves as an activator for TRPML2 and TRPML3 with EC 50 values of 2.7 μM and 10.8 μM respectively [1].’