Molecularly imprinted polymeric membranes involving tetrapeptide EQKL derivatives as chiral-recognition sites toward amino acids

Molecularly imprinted polymeric membranes, bearing the tetrapeptide derivative HGlu(OBzl)–Gln–Lys(4-Cl-Z)–Leu-CH2-, were prepared during the membrane preparation (casting) process in the presence of print molecule Boc-L-Trp or Ac-L-Trp. The membranes thus obtained showed adsorption selectivity toward the print molecule and its family. The tetrapeptide derivative in the imprinted membranes preferentially recognized an L-amino acid to the corresponding D-isomer. The affinity constant between Ac-L-Trp and the chiral recognition site was determined as 2.1×104 mol−1 dm3 from the adsorption isotherm of Ac-L-Trp. Enantioselective electrodialysis was attained with such a membrane, the L-isomer permeating in preference to the D-isomer.