02035nas a2200229 4500008004100000022001400041245020600055210007200261260000800333490000700341520114800348100001901496700001901515700001401534700001601548700001601564700002401580700002001604700001701624700002001641856014401661 2017 eng d a0022-326300aAcyclic αγα-tripeptides with fluorinated- and nonfluorinated-furanoid sugar framework: importance of fluoro substituent in reverse-turn induced self-assembly and transmembrane ion-transport activity0 aAcyclic αγαtripeptides with fluorinated and nonfluorinatedfurano cJUN0 v823 a
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+···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. 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.
1 aBurade, S., S.1 aShinde, S., V.1 aBhuma, N.1 aKumbhar, N.1 aKotmale, A.1 aRajamohanan, P., R.1 aGonnade, R., G.1 aTalukdar, P.1 aDhavale, D., D. uhttp://library.ncl.res.in/content/acyclic-%CE%B1%CE%B3%CE%B1-tripeptides-fluorinated-and-nonfluorinated-furanoid-sugar-framework-importance