Table 6. Stability of m-Amide Linker–Payloads^a.

reagent	2	14	15	16
cathepsin B	100	100	100	100
human serum	0	0	0	0
mouse serum	100	50	31	7

^aValues shown are % drug release in 24 h. Compounds 2 and 14 were used as NAC derivatives.