Synthetic cinchonidine receptors obtained by cross-linking linear poly(methacrylic acid) derivatives as an alternative molecular imprinting technique.
A molecular imprinting approach to construct synthetic receptors was examined, wherein a linear pre-polymer bearing functional groups for intermolecular interaction with a given molecule is cross-linked in the presence of the molecule as a template, and subsequent removal of the template from the resultant network-polymer is expected to leave a complementary binding site. Poly(methacrylic acid) (PMAA) derivatized with a vinylbenzyl group as a cross-linkable side chain was utilized as the pre-polymer for the molecular imprinting of a model template, (-)-cinchonidine. Selectivity of the imprinted polymer was evaluated by comparing the retentions of the original template, (-)-cinchonidine and its antipode (+)-cinchonine in chromatographic tests, exhibiting a selectivity factor up to 2.4. By assessment of the imprinted polymers in a batch mode, a dissociation constant at 20 degrees C for (-)-cinchonidine was estimated to be K (d) = 2.35 x 10(-6) M (the number of binding sites: 4.54 x 10(-6) mol/g-dry polymer). The displayed affinity and selectivity appeared comparable to those of an imprinted polymer prepared by a conventional monomer-based protocol, thus showing that the pre-polymer, which can be densely cross-linked, is an alternative imprinter for developing template-selective materials. (-)-Cinchonidine-imprinted polymers were prepared and assessed using the pre-polymers bearing different densities of the vinylbenzyl group and different amounts of the cross-linking agent to examine the appropriate density of the cross-linking side chain that was crucial for developing the high affinity and selectivity of the imprinted polymers.
Matsui
Jun
J
Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.
Minamimura
Norihito
N
Nishimoto
Kenji
K
Tamaki
Katsuyuki
K
Sugimoto
Naoki
N
D002930:Cinchona Alkaloids / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012680:Sensitivity and Specificity
D002930:Cinchona Alkaloids; D008565:Membrane Proteins; D011109:Polymethacrylic Acids; C041622:cinchonidine