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Structural characterization of flavonoid C ‐ and O ‐glycosides in an extract of Adhatoda vasica leaves by liquid chromatography with quadrupole time‐of‐flight mass spectrometry
Author(s) -
Singh Awantika,
Kumar Sunil,
Bajpai Vikas,
Reddy T. Jagadeshwar,
Rameshkumar K. B.,
Kumar Brijesh
Publication year - 2015
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7202
Subject(s) - chemistry , glycoside , aglycone , chromatography , mass spectrometry , high performance liquid chromatography , formic acid , stereochemistry
Rationale Adhatoda vasica Nees is a well‐known Ayurvedic medicinal plant, belonging to the family Acanthaceae. This study aims to seek identification and characterization of flavonoid C ‐ and O ‐glycosides in the aqueous fraction of the plant leaves. Methods A method was developed for simultaneous characterization of flavonoids and their glycosides using high‐pressure liquid chromatography with quadrupole time‐of‐flight mass spectrometry (HPLC/ESI‐QTOF‐MS/MS). The chromatographic separation was carried on an Agilent Poroshell 120 EC‐C 18 column (4.6 × 150 mm, 2.7 µm) operated with 0.1% formic acid aqueous solution and methanol as the mobile phase. Results The fragmentations of the studied [M–H] − ions of C ‐glycosides were shown to be cross‐ring cleavages of the glycoside moiety [M–H–(60/90/120)] − whereas O ‐glycosides were shown to eliminate the sugar moiety (Y 0 − or [Y 0 –H] − ) from the aglycone unit; 6‐ C ‐glycosides exhibited [M–H–18] − , a characteristic ion, and also a higher abundance of 0,3 X 6 or 8 ions in comparison to 8‐ C glycosides; flavonoid 6,8‐di‐ C ‐glycosides exhibited cross‐ring cleavages of the sugar attached to the C‐6 position preferentially. Conclusions This method was successfully applied for analysis of flavonoids and their glycosides in Adhatoda vasica leaves. A total of 29 compounds were tentatively identified including 17 C ‐, nine O ‐glycosides and three flavonoids. Copyright © 2015 John Wiley & Sons, Ltd.