Table 2. Native-State MPO Equilibrium Dissociation Constants^a.

compound	pKd NMRb (n = 1)	pIC50 MPO (n = 3)
3	4.2	6.6
4	4.7	7.5
8	5.4	7.8
9	6.2	8.9
16	6.3	8.8

^aK_d, dissociation constant; MPO, myeloperoxidase; and NMR, nuclear magnetic resonance.

^bDetermined by competition experiments with benzohydroxamic acid (pK_d = 2.3).²⁰