Application of the rule of shielding in the design of novel fluorinated structural motifs and peptidomimetics

The local environment around the fluorine, which determines the ¹⁹F NMR chemical shift, appears to be of paramount importance for the recognition mechanism. Deshielded fluorine containing fragments, suitable for interacting efficiently with the amphiphatic α helix secondary structural motif and hydrophobic pockets on proteins, are discussed. Shielded fluorine containing scaffolds are proposed as novel peptide bond isosteres for potentially overcoming the major drawbacks of peptides, such as short physiological half-lives due to rapid proteolysis and poor bioavailability. These new fluorinated skeletons can be used for generating a diverse library of fluorinated peptidomimetics which can then be efficiently screened in mixtures against multiple targets by ¹⁹F NMR spectroscopy.