Abstract :
[en] This study aims to develop a separation-analysis technique for screening active compounds in herbal products by using molecularly imprinted polymers (MIPs). MIPs, composed of specific cavities designed upon a template molecule, have already shown a high efficiency to mimic the recognition characteristics exhibited by enzymes or receptors [1,2,3]. However efforts should be carried out to produce MIPs which exhibit cross-reactivity instead of absolute specificity. We hypothesize that a lower rigidity of the imprinted cavities should allow a more successful simulation of receptors binding pockets to permit the selective isolation of molecules analogue to the template used for MIP synthesis.
For the study of working conditions, we developed reference MIPs through bulk polymerization by using quercetin as template molecule, acrylamide (AA) as functional monomer and ethylene glycol dimethacrylate (EDMA) as cross-linker with tetrahydrofuran (THF) as porogen. Then, new synthesis strategies were tested in order to develop MIPs which exhibit 'Class Selectivity' for a family of compounds related to quercetin, the template molecule.
The synthesised MIPs were evaluated as solid-phase extraction (SPE) sorbents to confirm the presence of imprinted cavities. The performances of MIPs relatively to non-imprinted polymers (NIPs) were defined by the Imprinting Effect (IF = Rate of retention on the MIP / Rate of retention on the NIP). High IF values (>3) allowed to confirm the successful imprinting of the MIPs.
The MIPs were then packed in HPLC columns in order to study their selectivity towards analogues of quercetin. The obtained results confirmed the selectivity modulation thanks to original synthesis strategies, giving promising perspectives for our planned optimization of MIPs' reactivity.
[1] L. Zhu, L. Chen, X. Xu, Application of a Molecularly Imprinted Polymer for the Effective Recognition of Different Anti-Epidermal Growth Factor Receptor Inhibitors, Analytical Chemistry 75 (2003) 6381-6387.
[2] L. Zhu, X. Xu, Selective separation of active inhibitors of epidermal growth factor receptor from Caragana Jubata by molecularly imprinted solid-phase extraction, Journal of Chromatography A 991 (2003) 151-158.
[3] M. Huang, W. Pang, J. Zhang, S. Lin, J. Hu, A target analogue imprinted polymer for the recognition of antiplatelet active ingredients in Radix Salviae Miltiorrhizae by LC/MS/MS, Journal of Pharmaceutical and Biomedical Analysis 58 (2012) 12-18.
