Polyurea Bearing L-Lysinyl Residue as a Chiral Building Block and Its Application to Optical Resolution

Abstract

Chial polyureas were prepared from L-Lys-OEt and 2,4-TDI. The optimum polyaddition conditions were determined as follows: [L-Lys-OEt] = 2.08 x 10 -1 mol dm -3 and [2,4-TDI] = 2.50 x 10 -1 mol dmThe polyuera thus obtained gave a durable self-standing membrane and it was directly converted into molecular recognition membranes by applying an alternative molecular imprinting. The D-isomer molecularly imprinted membrane adsorbed the D-isomer in preference to the L-isomer and vice versa.In the present study, two types of print molecule, such as Z-D-Glu and Z-L-Glu, worked as print molecules though the polyurea consisted of L-lysinyl residue. Those two types of molecularly imprinted membrane showed chiral separation ability. The membrane, which was molecularly imprinted by the D-isomer and preferentially incorporated the D-isomer into the membrane, selectively transported the D-isomer and vice versa.

Molecularly Imprinted Chitin Nanofiber Membranes: Multi-Stage Cascade Membrane Separation within the Membrane

“…Contrary to the previous study [24], both enantiomers, such as D-and L-enantiomer of Ac-Phe-OH, worked well as print molecules toward chitin, though chitin consists of N-acetylglucosamine units, which are connected β-1,4 linkage. Nanofiber membranes imprinted by Ac-D-Phe-OH showed Denantiomer adsorption selectivity and vice versa like molecularly imprinted membranes from cellulose acetate [22,30], oligopeptide tweezers [31] and chiral polyurea [32][33][34][35]. In the case of molecularly imprinted membranes from synthetic polymers with no chiral center, both enantiomers worked well as print molecules [36,37], as expected.…”

Chiral Polyurea with L-Lysinyl Residue Aimed for Optical Resolution

“…The results of adsorption selectivity are summarized in Table 3. As observed in adsorption studies on other chiral polyurea membranes [18][19][20], the control polyurea membrane incorporated into the L-isomer of Glu in preference to the corresponding D-isomer. Even though the present control membrane showed adsorption selectivity, the value was not so prominent and determined to be 1.05. As reported [27][28][29][30][31][32], molecular imprinting is a facile way to bestow molecular recognition ability on polymeric materials.…”

“…In a link in the chain of studies on optical resolution with chiral polyurea [18][19][20], the chiral polyurea was prepared from L-lysine-4-nitroanilide (L-Lys-4-NA) as diamine component and 1,4-phenylene diisocyanate (1,4-PDI) as diisocyanate one. Its membrane performance was investigated adopting racemic mixture of glutamic acid (Glu) as a model racemate.…”

Molecularly Imprinted Membranes: Past, Present, and Future

“…There are many examples of using the principle of alternative molecular imprinting to create molecular recognition sites in polymers such as synthetic polymers, − oligopeptide derivatives, ,− derivatives of natural polymer, ,− and natural polymers. , …”

“…Chiral separation using dual-direction electrodialysis has also been realized with MIMs from carboxylated polysulfone and cellulose acetate . In contrast to MIMs from oligopeptide derivatives, as summarized in Figure , both the d - and l -enantiomers were found to work well as print molecules in the preparation of imprinted membranes from synthetic polymers, ,,,,− cellulose acetate, , oligopeptide tweezers, and tetrapeptide derivatives consisting of glycinyl residues …”