Fig. 4.

Titration of 5 mM PF1022A (1) with a KSCN solution in CD₃OH: Hα region of ¹H NMR spectra. Chemical shift changes were observed for the symmetric conformation, best seen for the signal of the Hα proton in residue Phl³⁷ (blue labels). In addition, a change in the ratio between the symmetric and asymmetric conformation is observed. Also the asymmetric conformation shows small changes in chemical shift at high salt concentrations. The titration plot for emodepside (2) can be found in the ESI.^†