title: Molecularly imprinted polymer for specific extraction of hypericin from Hypericum perforatum L. herbal extract.
abstract: The molecularly imprinted polymers (MIPs) were prepared by an oxidation-reduction polymerization system using a non-covalent molecularly imprinting strategy with hypericin as the template, acrylamide as the functional monomer and pentaerythritol triacrylate as the cross-linker in the porogen of acetone. The UV spectrum revealed that a cooperative hydrogen-bonding complex between hypericin and acrylamide might be formed at the ratio of 1:6 in the prepolymerized system. Two classes of the binding sites were produced in the resulting hypericin-imprinted polymer with the dissociation constants of 16.61μgL(-1) and 69.35μgL(-1), and the affinity binding sites of 456.53μgg(-1) and 603.06μgg(-1), respectively. The synthesized MIPs were characterized by scanning electron microscope, thermogravimetric and differential thermal analysis. High-performance liquid chromatography was used to investigate the adsorption and recognition properties of the MIPs. Selective binding of the template molecule was demonstrated in comparison to the analog pseudohypericin. After the Hypericum perforatum L. plant being air dried and finely ground, an extract was prepared by shaking the powder in a methanol-water solution (80:20, v/v), vacuum filtration though a Büchner funnel, liquid-liquid extraction with ethyl ether and ethyl acetate, and evaporating on a rotary evaporator until dry. With the sorbents of the optimized MIPs, a molecularly imprinted solid-phase extraction (MISPE) procedure was developed for enrichment and separation of hypericin from the Hypericum extract in the presence of interfering substances. The selective extraction of hypericin from herbal medicine was achieved with the recovery of 82.30%. The results showed that MISPE can be a useful tool for specific isolation and effective clean-up of target compounds from natural products.
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China. Electronic address: ilizhaozhou@126.com.
authors.forename: Zhaozhou
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
authors.forename: Cuili
authors.initials: C
authors.lastname: Qin
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China. Electronic address: lidm21@sohu.com.
authors.forename: Daomin
authors.initials: D
authors.lastname: Li
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
authors.forename: Yuze
authors.initials: Y
authors.lastname: Hou
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
authors.forename: Songbiao
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Sun
mesh_terms: D000096:Acetone / Q000737:chemistry; D020106:Acrylamide / Q000737:chemistry; D000179:Acrylates / Q000737:chemistry; D000327:Adsorption; D000873:Anthracenes; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D029001:Herbal Medicine / Q000379:methods; D006860:Hydrogen Bonding; D020902:Hypericum / Q000737:chemistry*; D059625:Liquid-Liquid Extraction / Q000379:methods; D054802:Molecular Imprinting / Q000379:methods; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods
chemical_list: D000179:Acrylates; D000873:Anthracenes; D010936:Plant Extracts; D011108:Polymers; D011409:Propylene Glycols; D000096:Acetone; D020106:Acrylamide; D010569:Perylene; C004965:hypericin; C056602:pseudohypericin; C027992:pentaerythrityl triacrylate
keywords: Hypericin; Hypericum perforatum L.; Molecularly imprinted polymer; Solid-phase extraction; pseudohypericin