A potent and selective MAO-B inhibitor (Kis = 110 and 1,450 nM for MAO-B and MAO-A, respectively); interacts with the catalytic site of human MAO-B in a reversible and competitive manner (activity increases from 37% to 97% following inhibitor washout, indicating TB5 binding is reversible); demonstrates permeability in a PAMPA blood-brain barrier model; has minimal cytotoxicity (>84% cell viability) in HepG2 cells at a concentrations up to 25 μM