Figure 5.

Cleavage of 1 b in aqueous buffer at pH 7 over time. The concentration was monitored by HPLC at 2, 4, 6, 8, 10, 12 and 24 hours (Figure S17). Solvent gradient for HPLC was 40–100 % B in 20 min; buffer B was MeOH with 0.1 % TFA and UV was measured at 220 nm. Integration of the peaks corresponding to the cleaved peptide and the intact peptide‐drug conjugate revealed that 52 % of the conjugate was cleaved after 10 hours.