title: Solid-phase extraction of galloyl- and caffeoylquinic acids from natural sources (Galphimia glauca and Arnicae flos) using pure zirconium silicate and bismuth citrate powders as sorbents inside micro spin columns.
abstract: Galloyl- and caffeoylquinic acids are among the most important pharmacological active groups of natural compounds. This study describes a pre-step in isolation of some selected representatives of these groups from biological samples. A selective solid-phase extraction (SPE) method for these compounds may help assign classes and isomer designations within complex mixtures. Pure zirconium silicate and bismuth citrate powders (325 mesh) were employed as two new sorbents for optimized SPE of phenolic acids. These sorbents possess electrostatic interaction sites which accounts for additional interactions for carbon acid moieties as compared to hydrophilic and hydrophobic sorbents alone. Based on this principle, a selective SPE method for 1,3,4,5-tetragalloylquinic acid (an anti-HIV and anti-asthamatic agent) as a starting compound was developed and then deployed upon other phenolic acids with success. The recoveries and selectivities of both sorbents were compared to most commonly applied and commercially available sorbents by using high performance liquid chromatography. The nature of interaction between the carrier sorbent and the acidic target molecules was investigated by studying hydrophilic (silica), hydrophobic (C18), mixed-mode (ionic and hydrophobic: Oasis(®) MAX) and predominantly electrostatic (zirconium silicate) materials. The newly developed zirconium silicate and bismuth citrate stationary phases revealed promising results for the selective extraction of galloyl- and caffeoylquinic acids from natural sources. It was observed that zirconium silicate exhibited maximum recovery and selectivity for tetragalloylquinic acid (84%), chlorogenic acid (82%) and dicaffeoylquinic acid (94%) among all the tested sorbents.
authors.affiliation: Institute of Analytical Chemistry and Radiochemistry, CCB-Center for Chemistry and Biomedicine, Leopold-Franzens University, Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Shah
authors.initials: S
authors.lastname: Hussain
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Schönbichler
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Güzel
authors.forename: Harald
authors.initials: H
authors.lastname: Sonderegger
authors.forename: Gudrun
authors.initials: G
authors.lastname: Abel
authors.forename: Matthias
authors.initials: M
authors.lastname: Rainer
authors.forename: Christian W
authors.initials: CW
authors.lastname: Huck
authors.forename: Günther K
authors.initials: GK
authors.lastname: Bonn
mesh_terms: D018650:Arnica / Q000737:chemistry*; D001685:Biological Factors / Q000737:chemistry; D001688:Biological Products / Q000737:chemistry; D002726:Chlorogenic Acid / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D031582:Galphimia / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D062385:Hydroxybenzoates / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D011208:Powders / Q000737:chemistry; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001685:Biological Factors; D001688:Biological Products; D062385:Hydroxybenzoates; D009942:Organometallic Compounds; D010936:Plant Extracts; D011208:Powders; D017640:Silicates; C472707:caffeoylquinic acid; D011801:Quinic Acid; D002726:Chlorogenic Acid; D015040:Zirconium; C002791:bismuth tripotassium dicitrate; C017616:phenolic acid
keywords: Arnicae flos; Bismuth citrate; Galphimia glauca; Phenolic acids; Solid-phase extraction; Zirconium silicate