title: Selectivity mapping of the binding sites of (E)-resveratrol imprinted polymers using structurally diverse polyphenolic compounds present in Pinot noir grape skins.
abstract: This investigation describes a general procedure for the selectivity mapping of molecularly imprinted polymers, using (E)-resveratrol-imprinted polymers as the exemplar, and polyphenolic compounds present in Pinot noir grape skin extracts as the test compounds. The procedure is based on the analysis of samples generated before and after solid-phase extraction of (E)-resveratrol and other polyphenols contained within the Pinot noir grape skins using (E)-resveratrol-imprinted polymers. Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionisation tandem mass spectrometry (ESI MS/MS) was then employed for compound analysis and identification. Under optimised solid-phase extraction conditions, the (E)-resveratrol-imprinted polymer showed high binding affinity and selectivity towards (E)-resveratrol, whilst no resveratrol was bound by the corresponding non-imprinted polymer. In addition, quercetin-3-O-glucuronide and a dimer of catechin-methyl-5-furfuraldehyde, which share some structural features with (E)-resveratrol, were also bound by the (E)-resveratrol-imprinted polymer. Polyphenols that were non-specifically retained by both the imprinted and non-imprinted polymer were (+)-catechin, a B-type procyanidin and (-)-epicatechin. The compounds that did not bind to the (E)-resveratrol molecularly imprinted polymer had at least one of the following molecular characteristics in comparison to the (E)-resveratrol template: (i) different spatial arrangements of their phenolic hydroxyl groups, (ii) less than three or more than four phenolic hydroxyl groups, or (iii) contained a bulky substituent moiety. The results show that capillary RP-HPLC in conjunction with ESI MS/MS represent very useful techniques for mapping the selectivity of the binding sites of imprinted polymer. Moreover, this procedure permits performance monitoring of the characteristics of molecularly imprinted polymers intended for solid-phase extraction of bioactive and nutraceutical molecules from diverse agricultural waste sources.
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia.
authors: Shima N N S
authors: SNNS
authors: Hashim
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia.
authors: Lachlan J
authors: LJ
authors: Schwarz
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia.
authors: Basil
authors: B
authors: Danylec
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia.
authors: Mahesh K
authors: MK
authors: Potdar
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia.
authors: Reinhard I
authors: RI
authors: Boysen
authors: Australian Centre for Research on Separation Science (ACROSS) Monash University, Monash, 3800 Victoria, Australia. Electronic address: milton.hearn@monash.edu.
authors: Milton T W
authors: MTW
authors: Hearn
mesh_terms: D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry*; D054802:Molecular Imprinting; D010936:Plant Extracts / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis*; D016062:Porosity; D000077185:Resveratrol; D021241:Spectrometry, Mass, Electrospray Ionization; D013267:Stilbenes / Q000737:chemistry*; D013499:Surface Properties; D053719:Tandem Mass Spectrometry; D027843:Vitis
chemical_list: D010936:Plant Extracts; D011108:Polymers; D059808:Polyphenols; D013267:Stilbenes; D000077185:Resveratrol
keywords: Molecularly imprinted polymers; Non-covalent imprinting; Polyphenols; Solid-phase extraction