Characterization of Steroidal Saponins from Dioscorea villosa and D. cayenensis Using Ultrahigh Performance Liquid Chromatography/Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry
2014
Yam ( Dioscorea spp.) is an important edible tuber plant used for
medicinal purposes to promote health and longevity in Chinese tradition.
Steroidal saponins were reported to be the major physiologically active
constituents in yams. In this current work, the structural characteristics
of steroidal saponins in methanolic extracts from dried rhizomes of two
Dioscorea species ( D. villosa L. and D. cayenensis Lam.) and dietary supplements have been identified and analyzed using
UHPLC/QTOF-MS in both negative and positive ion modes. The fragmentation
patterns of reference standards were determined and the steroidal saponins
in the extracts were identified or tentatively characterized from their
retention times and mass spectra. The fragments produced by
collision-induced dissociation (CID) revealed the characteristic cleavage of
glycosidic bonds, and the fragmentation pattern provided structural
information about the sugars. Twenty-one saponins, including four
tentatively identified compounds, were detected in the crude extracts of two
Dioscorea species. These saponins can be used to distinguish
D. villosa from D. cayenensis . For example, asperin and
gracillin are found only in D. cayenensis , and dioscoreavilloside A
and B and parvifloside are only found in D. villosa . This can be used
to determine the presence or absence of D. villosa in commercial
products, which may help determine the spiking of plant material, and/or
prevent the use of potentially mislabeled or misidentified
“ Dioscorea” material. The analytical method also provided an
alternative, fast method for quality control of Dioscorea species in
dietary supplements. Principal component analysis showed that
Dioscorea species and commercial products were easily
distinguished. From this a partial least squares model was constructed to
determine what species are in different products.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
28
References
13
Citations
NaN
KQI