Acyclic αγα-tripeptides with fluorinated- and nonfluorinated-furanoid sugar framework: importance of fluoro substituent in reverse-turn induced self-assembly and transmembrane ion-transport activity

TitleAcyclic αγα-tripeptides with fluorinated- and nonfluorinated-furanoid sugar framework: importance of fluoro substituent in reverse-turn induced self-assembly and transmembrane ion-transport activity
Publication TypeJournal Article
Year of Publication2017
AuthorsBurade, SS, Shinde, SV, Bhuma, N, Kumbhar, N, Kotmale, A, Rajamohanan, PR, Gonnade, RG, Talukdar, P, Dhavale, DD
JournalJournal Of Organic Chemistry
Volume82
Start Page5826-5834
Issue11
Date PublishedJUN
ISSN0022-3263
Abstract

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.

DOI10.1021/acs.joc.7b00661
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

4.785

Divison category: 
Central NMR Facility