Preparation of molecule imprinted membrane of single enantiomer of amino acid with an innovative strategy and study on its chiral recognition and resolution properties

BACKGROUND The molecularly imprinted membranes (MIMs) with high performance are very valuable in the chiral resolution of amino acids. In this work, a novel molecularly imprinted membrane of the single enantiomer of amino acids with graft type was successfully prepared by using an advanced surface imprinting technique. The aminated microfiltration membrane of polysulfone, AMPSF membrane, was first prepared, and so a surface-initiating system of -NH2/S2O8- was constituted. In an aqueous solution, the molecules of dimethylaminoethyl methacrylate (DMAEMA) as functional monomer were combined around L-glutamic acid (L-Glu) as template by right of electrostatic interaction and hydrogen bonding. By initiating of -NH2/S2O8- system, DMAEMA and the crosslinking agent N,N′-Methylenebisacrylamide (MBA) produced graft/crosslinking-polymerization on the surface of AMPSF membrane, whereas L-Glue molecules were wrapped within the grafted polymer layer, obtaining grafting type L-Glue molecule-imprinted membrane (L-Glue-MIM). The ability of the chiral recognition and enantioseparation of L-Glue-MIM were examined. RESULTS The experimental results show that L-Glue-MIM possesses specific chiral recognition selectivity and excellent enantioseparation ability. In the permeation experiment, L-Glue molecules in the raceme solution can smoothly pass across L-Glue-MIM, but D-Glue molecules are seriously blocked. As a result, Glu raceme solution is well separated, and the optical purity (ee value) of the penetrating fluid gets up to 82%. CONCLUSION Grafting type molecularly imprinted membrane of the single enantiomer of amino acids was successfully prepared by using an innovative and advanced surface-imprinting technique of "synchronously graft-polymerizing and molecule imprinting", and it supplies a newer route to prepare imprinted membrane with high performance for chiral resolution of amino acids and other chiral drugs. Such study is reported for the first time. © 2017 Society of Chemical Industry