Table 1. Processing Data for Target Compounds 6 by FAP and PREP^a,b.

^aValues are represented as the mean ± standard deviation (n = 3; for 6h and 6i: n = 2).

^bNone of the compounds in Table 1 displayed substrate inhibition (si) toward FAP, except compound 6a (K_si = 29 ± 6 μM).

^cSI = selectivity index, defined as k_cat/K_m (FAP)/k_cat/K_m (PREP).

^dNP = not processed; no cleavage of the substrate was observed at the highest concentration that was evaluated.

^eND = not determined; no active site saturation could be reached in the concentration range that was used.

^fNA = not applicable.