Two-stage mass spectrometry approach for the analysis of triterpenoid glycosides in Fagonia indica†
Triterpenoid glycosides are molecules widely distributed in plants and have shown a wide range of biological activities against various diseases. This paper describes the qualitative and quantitative analysis of triterpenoid glycoside (saponins) using a two-stage mass spectrometry approach in five samples of Fagonia indica collected from various parts of the country. In the first stage, triterpenoid glycosides were identified using liquid chromatography high-resolution mass spectrometry using UHPLC-QTOF-MS system. In the second stage, compounds were quantified using a multiple reaction monitoring (MRM) approach using an UHPLC-QQQ-MS system. Fagonia indica has shown a wide range of biological activities and found to be rich in saponin or triterpenoid glycoside constituents. A total of thirteen triterpenoid saponins were identified based on high-resolution analysis, MS/MS and database comparison, while six of them were simultaneously quantified using the multiple reaction monitoring (MRM) approach. The results indicate that the samples share a similar UHPLC pattern, however, the amount of these saponins in samples varies greatly. Compound 4 i.e. nayabin D was the major constituent (1.4–3.8 μg g−1) among the six analyzed compounds. The results demonstrated that the developed multi-compound determination in combination with a fingerprint analysis method is rapid, accurate, precise and sensitive and can be utilized for quality control and high-throughput quantification of various saponins in Fagonia indica may be extended to other plant species.