1.D.80. The Fluorinated Sugar-Tripeptide (FSTP) Family
Acyclic αγα-tripeptides derived from fluorinated-furanoid sugar amino acid frameworks act as reverse-turn inducers with a U-shaped conformation, whereas the corresponding nonfluorinated αγα-tripeptides show random peptide conformations (Burade et al. 2017). NMR studies showed that the presence of bifurcated weak intramolecular hydrogen bonding (F···HN) and N+···Fδ- charge-dipole attraction compel the amide carbonyl groups to orient antiperiplanar to the C-F bond, thus, demonstrating the role of the fluorine substituent in stabilizing the U-shaped conformation. A pentameric self-assembly has been demonstrated, and these show fibers that form nanorods. The antiparallel self-assembled pore of the fluorinated tripeptides promote selective anion-transport activity.The order of anion selectivity was: SCN- > Cl- > NO3- > AcO- > F- (Burade et al. 2017).