Enantioselective recognition of a chiral quaternary ammonium ion by C-3 symmetric cyclic hexapeptides

C-3 Symmetric cyclic hexapeptides containing alternating L-proline and 3-aminobenzoic acid derivatives as subunits possess different affinities towards the two enantiomers of the N,N,N-trimethyl-1-phenylethyl ammonium cation.