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| Content Provider | World Health Organization (WHO)-Global Index Medicus |
|---|---|
| Author | Magalhães, Paulo J. Barros, Aquiles A. Gonçalves, Luís M. Pacheco, João G. Guido, Luís F. Vieira, Joana S. |
| Description | Country affiliation: Portugal Author Affiliation: Magalhães PJ ( REQUIMTE, Departamento de Química da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, No 687, 4169-007 Porto, Portugal. pauloxenon@gmail.com) |
| Abstract | The aim of the present work was the development of a suitable methodology for the separation and determination of phenolic compounds in the hop plant. The developed methodology was based on the sample purification by adsorption of phenolic compounds from the matrix to polyvinylpolypyrrolidone (PVPP) and subsequent desorption of the adsorbed polyphenols with acetone/water (70:30, v/v). At last, the extract was analyzed by HPLC-DAD and HPLC-ESI-MS/MS. The first phase of this work consisted of the study of the adsorption behavior of several classes of phenolic compounds (e.g. phenolic acids, flavonols, and flavanols) by PVPP in model solutions. It has been observed that the process of adsorption of the different phenolic compounds to PVPP (at low concentrations) is differentiated, depending on the structure of the compound (number of OH groups, aromatic rings, and stereochemistry hindrance). For example, within the phenolic acids class (benzoic, p-hydroxybenzoic, protocatechuic and gallic acids) the PVPP adsorption increases with the number of OH groups of the phenolic compound. On the other hand, the derivatization of OH groups (methylation and glycosylation) resulted in a greatly diminished binding. The use of PVPP revealed to be very efficient for adsorption of several phenolic compounds such as catechin, epicatechin, xanthohumol and quercetin, since high adsorption and recovery values were obtained. The methodology was further applied for the extraction and isolation of phenolic compounds from hops. With this methodology, it was possible to obtain high adsorption values (>or=80%) and recovery yield values (>or=70%) for the most important phenolic compounds from hops such as xanthohumol, catechin, epicatechin, quercetin and kaempferol glycosides, and in addition it allows the identification of about 30 phenolic compounds by HPLC-DAD and HPLC-ESI-MS/MS. |
| ISSN | 00219673 |
| Issue Number | 19 |
| Volume Number | 1217 |
| e-ISSN | 18733778 |
| Journal | Journal of Chromatography A |
| Language | English |
| Publisher | Elsevier |
| Publisher Date | 2010-05-07 |
| Publisher Place | Netherlands |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Chromatography, High Pressure Liquid Methods Flavonoids Isolation & Purification Humulus Chemistry Phenols Povidone Analogs & Derivatives Spectrometry, Mass, Electrospray Ionization Tandem Mass Spectrometry Adsorption Catechin Equipment Reuse Plant Extracts Propiophenones Quercetin Temperature Journal Article Discipline Analytical Chemistry |
| Content Type | Text |
| Resource Type | Article |
| Subject | Organic Chemistry Medicine Analytical Chemistry Biochemistry |
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