H-1 NMR determination of hypericin and pseudohypericin in complex natural mixtures by the use of strongly deshielded OH groups
Φόρτωση...
Ημερομηνία
Συγγραφείς
Tatsis, E. C.
Exarchou, V.
Troganis, A. N.
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
The H-1 NMR spectra of the commercially available compounds hypericin and its derivative pseudohypericin in CD3OH solutions indicate significantly deshielded signals in the region of 14-15 ppm. These resonances are attributed to the peri hydroxyl protons OH(6), OH(8) and OH(1), OH(13) of hypericins which participate in a strong six-membered ring intramolecular hydrogen bond with CO(7) and CO(14), respectively, and therefore, they are strongly deshielded. In the present work, we demonstrate that one-dimensional H-1 NMR spectra of hypericin and pseudohypericin, in Hypericum perforatum extracts show important differences in the chemical shifts of the hydroxyl groups with excellent resolution in the region of 14-15 ppm. The facile identification and quantification of hypericin and its derivative compound pseudohypericin was achieved, without prior HPLC separation, for two H. perforatum extracts from Greek cultivars and two commercial extracts: a dietary supplement, and an antidepressant medicine. The results were compared with those obtained from UV-vis and LC/MS measurements. (C) 2007 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
h-1 nuclear magnetic resonance, hypericin, pseudohypericin, hypericum perforatum, intramolecular hydrogen bond, peri hydroxyl groups, st-johns-wort, performance liquid-chromatography, magnetic-resonance-spectroscopy, intramolecular hydrogen-bonds, mass-spectrometry, nmr-spectroscopy, quantitative-analysis, qnmr spectroscopy, products analysis, chemical-shifts
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000252758000013
http://ac.els-cdn.com/S0003267007019198/1-s2.0-S0003267007019198-main.pdf?_tid=fc84ff94-3246-11e3-ae54-00000aab0f01&acdnat=1381476801_902b8ffca195babcb001467d8bfe98cc
http://ac.els-cdn.com/S0003267007019198/1-s2.0-S0003267007019198-main.pdf?_tid=fc84ff94-3246-11e3-ae54-00000aab0f01&acdnat=1381476801_902b8ffca195babcb001467d8bfe98cc
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