QUERCETIN IMPRINTED POLYMERS: PREPARATION AND PROPERTIES AS SORBENT FOR SOLID-PHASE EXTRACTION

Molecularly imprinted polymers (MIPs), composed of specific cavities designed for a template molecule, allow the development of a retention mechanism based on molecular recognition. Our objective to separate and to screen active compounds from natural origin, leads us to develop new MIP particles which exhibit 'Class Selectivity' for a family of related compounds. Indeed, such MIPs could mimic the recognition characteristics exhibited by the natural receptors. Therefore, the imprinted sites with a known inhibitor could trap analogues that exhibit stronger inhibiting properties. Our new MIPs were prepared through thermal polymerization by using quercetin as the polar template molecule (a flavonoid with chemopreventive properties), acrylamide (AA) as the functional monomer and ethylene glycol dimethacrylate (EDMA) as the cross-linker with tetrahydrofuran (THF) as porogen. Synthesized MIPs were tested as solid-phase extraction (SPE) sorbent in order to study their selectivities towards analogs and non-analogs of quercetin. The performances of MIPs relatively to non-imprinted polymers (NIPs) are defined by the Imprinting Effect (IF = Rate of retention on the MIP / Rate of retention on the NIP). After optimization of SPE elution protocol (THF as washing solvent and MeOH as elution solvent), successful imprinting was confirmed by high IF values (>3) and the binding capacity of the MIPs for quercetin was determined. Besides, quercetin structurally related compounds were selected to assess the MIPs selectivity. After comparison,the MIPs exhibited the highest selective rebinding to quercetin. The application of MIPs with high affinity and excellent stereo-selectivity toward quercetin in SPE offers us an excellent starting point for our further planned optimization of selectivity modulation.