1H nuclear magnetic resonance study of the molecular imprinting of (-)-nicotine: template self-association, a molecular basis for cooperative ligand binding.
In the present study, the interactions of components in a (-)-nicotine molecular imprinting polymerization mixture have been studied by 1H NMR spectroscopy. The dissociation constants for complexation of template by a functional monomer analogue, acetic acid, have been determined. Nicotine was shown to self-associate at concentrations comparable to those used in previous molecular imprinting studies (app K(diss) = 0.082M in CDCl3 at 298 K). The extent of self-association was enhanced by the presence of acetic acid. Previous studies on (-)-nicotine-imprinted methacrylic acid-ethylene dimethacrylate co-polymers suggested the involvement of recognition sites for template-template complexes. Collectively these results provide the first direct evidence for the presence of template-template complexes, and support the previously hypothesized basis for cooperative ligand recognition events in this polymer system.
Svenson
Johan
J
Department of Chemistry and Biomedical Sciences, University of Kalmar, SE-391 82 Kalmar, Sweden.
Karlsson
Jesper G
JG
Nicholls
Ian A
IA
D001704:Biopolymers; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009538:Nicotine / Q000737:chemistry* / Q000378:metabolism
D001704:Biopolymers; D008024:Ligands; D009538:Nicotine