Syntheses of fluorinated sugar amino acid derived α,γ-cyclic tetra- and hexapeptides are reported. The IR, NMR, ESI-MS, CD, and molecular modeling studies of cyclic tetra- and hexapeptides showed C and C symmetric flat oval- and triangular-ring shaped β-strand conformations, respectively, which appear to self-assemble into nanotubes. The α,γ-cyclic hexapeptide (EC = 2.14 μM) is found to be a more efficient ion transporter than α,γ-cyclic tetrapeptide (EC = 14.75 μM). The anion selectivity and recognition of α,γ-cyclic hexapeptide with NO ion is investigated.

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. The NMR studies showed the presence of bifurcated weak intramolecular hydrogen bonding (F···HN) and N···F 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. The NOESY data indicate that the U-shaped tripeptides self-assembly formation is stabilized by the intermolecular hydrogen bonding between C═O···HN with antiparallel orientation. This fact is supported by ESI-MS data, which showed mass peaks up to the pentameric self-assembly, even in the gas phase. The morphological analysis by FE-SEM, on solid samples, showed arrangement of fibers into nanorods. The antiparallel self-assembled pore of the fluorinated tripeptides illustrates the selective ion-transport activity. The experimental findings were supported by DFT studies.

Phosphoramidite building blocks of CF3‐modified N4(6‐amino‐2‐pyridinyl)deoxycytidines were synthesized, incorporated into triplex‐forming 2′‐deoxyoligonucleotide strands and the applicability of the probes to recognize nucleobase content in the pyrimidine‐rich strand of double‐helical DNA targets was evaluated. As expected, the obtained 19F NMR resonances were sensitive to the base content and unique 19F NMR spectral fingerprints could be obtained.

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