Fig. 5. The backbone overlay of an ensemble of ten minimum energy conformations obtained from 10 ns restrained molecular dynamics simulation of (A) 3n, (B) 4g and (C) 5 in water. Note the flexibility of the β-turn with a shorter β-strand registry in 3n. The 90° rotation of the β-sheets clearly depicts the enhanced right-handed twist in 3n and 5. The dotted lines indicate the flexibility of the turn in 3n as opposed to 5 and 4g. The side chains are omitted for the sake of clarity (ESI†). The NMR spectra of 3n, 4g and 5 were acquired in acetate buffer (pH 3.8) at 25 °C.