Novel determination of the total phenolic content in crude plant extracts by the use of H-1 NMR of the -OH spectral region
Φόρτωση...
Ημερομηνία
Συγγραφείς
Nerantzaki, A. A.
Tsiafoulis, C. C.
Charisiadis, P.
Kontogianni, V. G.
Gerothanassis, I. P.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier Masson
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Analytica Chimica Acta
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
A novel method for the determination of the total phenolic content using H-1 NMR spectroscopy in the -OH spectral region is presented. The use of DMSO-d(6), which is an aprotic and strongly hydrogen bonding solvent, allows the "appearance" of the relative sharp resonances of phenolic hydroxyl protons in the region of 8-14 ppm. The determination of the total phenolic -OH content requires three steps: (i) a 1D H-1 NMR spectrum is obtained in DMSO-d(6); (ii) a subsequent 1D H-1 NMR spectrum is recorded with irradiation of the residual water signal which results in the elimination or reduction of the phenolic -OH groups, due to proton exchange; and (iii) 1D H-1 NMR spectra are recorded with the addition of a progressively increased amount of salt. NaHCO3, which results in extensive linebroadening of the COOH resonances thus allowing the discrimination of the phenolic from the carboxylic acid signals. Integration, with respect to the internal standard TSP-d(4). of the signal resonances between 14 and 8 ppm in spectrum (i) which are either eliminated or reduced in intensity in steps (ii) and (iii) allows the quantitation of the total phenolic content. The method was applied to model compounds, a mixture of them and several extracts of natural products. The results of the proposed H-1 NMR method were compared to the Folin-Ciocalteu (FC) reagent method. Additionally, since H-1 NMR refers to the total phenolic hydroxyl protons, a reaction factor, A(e), is proposed that corresponds to the hydroxyl reactivity. The H-1 NMR method is rapid and accurate bearing the inherent advantages of the NMR spectroscopy and can be applied directly in complex extracts. Furthermore, it can be applied in a wide range of matrixes from crude plant extracts and food products to biological samples. (C) 2011 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
h-1 nmr, -oh spectral region, total phenolic content, flavonoids, phenolic acid, plant extracts, hydroxyl reactivity, nuclear-magnetic-resonance, virgin olive oil, green tea, capillary-electrophoresis, spectroscopy, complex, cancer, quantification, identification, wines
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000287775200006
http://ac.els-cdn.com/S0003267010015965/1-s2.0-S0003267010015965-main.pdf?_tid=dcf02d70-3246-11e3-b1e6-00000aacb35e&acdnat=1381476748_59e990ccea7476b1f819aa7bcd0e6f89
http://ac.els-cdn.com/S0003267010015965/1-s2.0-S0003267010015965-main.pdf?_tid=dcf02d70-3246-11e3-b1e6-00000aacb35e&acdnat=1381476748_59e990ccea7476b1f819aa7bcd0e6f89
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας