Tandem Solid-Phase Extraction Followed by HPLC–ESI/QTOF/MS/MS for Rapid Screening and Structural Identification of Trace Diterpenoids in Flowers of Rhododendron molle
Article first published online: 23 JAN 2014
Copyright © 2014 John Wiley & Sons, Ltd.
Volume 25, Issue 3, pages 255–265, May/June 2014
How to Cite
Zou, H.-Y., Luo, J., Xu, D.-R. and Kong, L.-Y. (2014), Tandem Solid-Phase Extraction Followed by HPLC–ESI/QTOF/MS/MS for Rapid Screening and Structural Identification of Trace Diterpenoids in Flowers of Rhododendron molle. Phytochem. Anal., 25: 255–265. doi: 10.1002/pca.2501
- Issue published online: 14 APR 2014
- Article first published online: 23 JAN 2014
- Manuscript Accepted: 29 NOV 2013
- Manuscript Revised: 27 NOV 2013
- Manuscript Received: 29 JUL 2013
- Rhododendron molle
‘Naoyanghua’, composed of the flowers of Rhododendron molle G. Don, is a traditional Chinese medicine that is widely known for its toxicity. Grayanane-type diterpenoids are the main active ingredients in R. molle, as well as possibly their toxicity: they are, however, difficult to isolate and analyse using common chromatographic methods, due to their small amounts and absence of conjugated groups, such as phenyl and α, β-unsaturated ketone.
To establish a highly sensitive, selective and reliable method for the qualitative evaluation of trace diterpenoids in the flowers of R. molle by using tandem solid-phase extraction followed by high-performance liquid chromatography with electrospray ionisation quadrupole-time-of-flight mass spectrometry (HPLC–ESI/QTOF/MS/MS).
Tandem solid phase extraction (SPE) was undertaken using a polyamide cartridge and a C18E cartridge in succession to enrich the trace diterpenoids. HPLC–ESI/QTOF/MS/MS was used to determine the fragmentation patterns of diterpenoids and to tentatively characterise their fragmentation pathways.
HPLC–ESI/QTOF/MS/MS detected a total of 14 diterpenoids, eight of which were identified by comparison with literature sources and six based on fragmentation analysis. Among the latter six, rhodojaponin VI-3-glucoside was tentatively identified as a new diterpenoid glycoside and rhodojaponin VII, rhodojaponin IV and rhodojaponin I were reported from R. molle for the first time.
By qualitative research of diterpenoids in this plant by HPLC–ESI/QTOF/MS/MS, a reliable methodology for the analysis of these active constituents of R. molle was established for the first time. Copyright © 2014 John Wiley & Sons, Ltd.