Table 1. IC₅₀s for Reference Compounds 1 and 2.

	IC50 (μM)
Nr	FAP	DPP IV	DPP9	DPP II	PREP
1	0.07 ± 0.01	0.022 ± 0.001	NDa	0.086 ± 0.007	0.98 ± 0.06
2	0.37 ± 0.002	0.0020 ± 0.0002	>100	>100	>100

^aNot determined.