Comprehensive two-dimensional liquid chromatography tandem diode array detector (DAD) and accurate mass QTOF-MS for the analysis of flavonoids and iridoid glycosides in Hedyotis diffusa
- 1k Downloads
The analysis of chemical constituents in Chinese herbal medicines (CHMs) is a challenge because of numerous compounds with various polarities and functional groups. Liquid chromatography coupled with quadrupole time-of-flight (QTOF) mass spectrometry (LC/MS) is of particular interest in the analysis of herbal components. One of the main attributes of QTOF that makes it an attractive analytical technique is its accurate mass measurement for both precursor and product ions. For the separation of CHMs, comprehensive two-dimensional chromatography (LCxLC) provides much higher resolving power than traditional one-dimensional separation. Therefore, a LCxLC-QTOF-MS system was developed and applied to the analysis of flavonoids and iridoid glycosides in aqueous extracts of Hedyotis diffusa (Rubiaceae). Shift gradient was applied in the two-dimensional separation in the LCxLC system to increase the orthogonality and effective peak distribution area of the analysis. Tentative identification of compounds was done by accurate mass interpretation and validation by UV spectrum. A clear classification of flavonol glycosides (FGs), acylated FGs, and iridoid glycosides (IGs) was shown in different regions of the LCxLC contour plot. In total, five FGs, four acylated FGs, and three IGs were tentatively identified. In addition, several novel flavonoids were found, which demonstrates that LCxLC-QTOF-MS detection also has great potential in herbal medicine analysis.
KeywordsComprehensive two-dimensional liquid chromatography LCxLC Hedyotis diffusa Chinese herbal medicine Flavonoids Iridoid glycosides
The authors thank Agilent (Waldbronn, Germany) for the test version of the new LCxLC add-on for Chemstation ver. B.04.03 and an additional UHPLC pump and Phenomenex (Aschaffenburg, Germany) for the columns.
- 12.Cho WC (2011) Evidence-based anticancer materia medica. Evidence-based anticancer complementary and alternative medicine. Springer, Dordrecht Heidelberg London New YorkGoogle Scholar
- 16.Hamad MN (2012) Pharm Globale (IJCP) 4(1):1–3Google Scholar
- 18.Fathiazad F, Delazar A, Amiri R, Sarker SD (2010) Iran J Pharm Res 5(3):222–227Google Scholar
- 19.Lajis NH, Ahmad R (2006) Phytochemical studies and pharmacological activities of plants in genus Hedyotis/oldenlandia. In: Atta-ur R (Ed) Studies in Natural Products Chemistry, vol 33. Elsevier: pp 1057–1090. http://www.sciencedirect.com/science/article/pii/S1572599506800463#