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

Molecularly imprinted polymeric membranes, bearing the tetrapeptide derivative HGlu(OBzi)-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 x 10(4) mol(-1) dm(3) 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. (C) 1998 Elsevier Science B.V.