M-31850 is a potent, selective and competitive β-hexosaminidase (Hex) inhibitor with IC50s of 6.0 μM and 3.1 μM for human HexA and human HexB, respectively. M-31850 also competitively inhibits β-N-acetyl-D-hexosaminidase OfHex2 with a Ki of 2.5 μM[1][2].