Fig. 2. (A) 1H NMR spectra of cyclo(RGDfV) (6) and its thio-analogs 7–11. The γ-CH3 of Val in both the conformers (A and B) of 6 is shown. (B) The solution structures of 7–11 deduced from 2D 1H NMR spectroscopy in aqueous conditions. (C) 1H NMR spectra of cyclo(RGDFV) (12) showing two conformers. (D) Solution structures of spatial screen analogs of 9 (9a–9d). The temperature coefficients of the amide protons (ppb K–1) are shown and the asterisk denotes the site of the d-amino acid (Gly in 9b). Significant resonance overlap precluded the structure determination of 6 and 12. The hydrogen atoms are omitted for the sake of clarity.
