The solvent exposure of peptide backbone NH groups can be studied using variable temperature 1 H-NMR experiments, where the change in chemical shift of the amide protons is observed upon increasing temperature. The shift of the amide NH signal in relationship to the temperature (Δδ NH /ΔT in ppb/K) highlights whether it is solvent exposed. Large shifts (Δδ NH /ΔT < -4.6 ppb/K) upon increasing temperatures indicate that the amide proton is solvent exposed while the opposite is true when the amide proton is shielded (Δδ NH /ΔT ≥ -4.6 ppb/K). These experiments were performed for compounds SA-A1, SA-B1, SA-B2, and SA-B3 in both DMSO as a mimic of a polar environment and CDCl 3 as a mimic of the hydrophobic membrane environment (Fig. -S9, and table and). In DMSO, the observed shifts for the Sanguinamide A (SA-A1) were similar to those observed previously by Nielsen et al. even though they used D 2 O as the solvent. All SA-B peptides were similar to SA-A1 albeit in an opposite direction for most amides. Slight changes were observed in SA-B1 where Phe-2 seemed to be more shielded while Ile-6 was more exposed in comparison to SA-A1. For SA-B3 the Ile-6 amide was also more exposed to solvent, but the change in Phe-2 shift was much smaller. Overall, these results suggest that only minor conformational changes occurred between all compounds in DMSO. However, it has to be noted that a minor second conformer was observed for the SA-B compounds which was not the case for SA-A1. In CDCl 3 , again only minor differences were observed for all SA-B peptides in comparison to SA-A1. Although various values changed somewhat, they never crossed the 4.6 ppd/K barrier in either direction. The biggest changes were observed for SA-B2, where increased shielding of Phe-2 and Ile-6 was observed. . Table : VT-NMR analysis of SA-A1, SA-B1, SA-B2, and SA-B3 in CDCl3. Reported are the ΔδNH/ΔT in ppb/K.