title: Preparation, characterization and usage of molecularly imprinted polymer for the isolation of quercetin from hydrolyzed nettle extract.
abstract: Quercetin (3,3',4',5,7-pentahydroxyflavone, QC) is a health-beneficial flavonoid, widely occurring in leaves, fruits, and flowers of various plants. In this work aiming isolation, purification and pre-concentration of QC, QC imprinted polymers (QC-MIPs) in different molar ratios {template:monomer:cross-linker (1:4:20, 1:5:30, 1:8:40, 1:10:50)} were prepared thermally through bulk polymerization by using QC as the template molecule, 4-vinylpyridine (4-VP), methacrylic acid (MAA), acrylamide (AA) as the functional monomers, ethylene glycol dimethacrylate (EDMA) as the cross-linker and 2,2'-azobisisobutyronitrile (AIBN) as initiator in the porogens of acetone and tetrahydrofuran. Their recognition and selectivity properties were investigated in solutions containing QC and other similar-structure phenolics by equilibrium binding experiments using different proportions of acetonitrile (ACN)-dimethylsulfoxide (DMSO) mixtures and methanol (MeOH) as solvents. The MIP with 1:4:20 molar ratio of QC:4-VP:EDMA was established as the most suitable for recognition of QC. Sorption parameters of the MIP and the NIP (non-imprinted polymer) were calculated by using Freundlich and Langmuir isotherms with QC solutions in ACN:DMSO (98:2, v/v). The mentioned MIP was found to be highly selective for quercetin over other phenolic compounds (rutin, catechin, etc.). Thus, molecularly imprinted solid-phase extraction (MISPE) procedures were applied for selective pre-concentration and purification of QC from synthetic mixtures of phenolic compounds and nettle extract, known as a source of official and folk medicine. The results demonstrated the possibility of direct extraction of certain pharmacophoric constituents such as QC and QC derivatives from nettle by MIP separation.
authors.affiliation: Fatih University, Vocational School of Health Sciences, Maltepe, 34844 Istanbul, Turkey.
authors.forename: Şeyda
authors.initials: Ş
authors.lastname: Karaman Ersoy
authors.affiliation: Istanbul University, Faculty of Engineering, Department of Chemistry, Avcilar, 34320 Istanbul, Turkey. Electronic address: etutem@istanbul.edu.tr.
authors.forename: Esma
authors.initials: E
authors.lastname: Tütem
authors.affiliation: Istanbul University, Faculty of Engineering, Department of Chemistry, Avcilar, 34320 Istanbul, Turkey.
authors.forename: Kevser
authors.initials: K
authors.lastname: Sözgen Başkan
authors.affiliation: Istanbul University, Faculty of Engineering, Department of Chemistry, Avcilar, 34320 Istanbul, Turkey.
authors.forename: Reşat
authors.initials: R
authors.lastname: Apak
authors.affiliation: Fatih University, Faculty of Arts and Sciences, B. Çekmece, 34500 Istanbul, Turkey.
authors.forename: Cevdet
authors.initials: C
authors.lastname: Nergiz
mesh_terms: D000327:Adsorption; D006868:Hydrolysis; D054802:Molecular Imprinting; D010936:Plant Extracts / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011794:Quercetin / Q000302:isolation & purification*; D052616:Solid Phase Extraction; D026982:Urtica dioica / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D011108:Polymers; D011794:Quercetin
keywords: Molecularly imprinted polymer; Nettle; Quercetin imprinted solid phase extraction; Quercetin recovery