The qualitative and quantitative analyses of Gelsemium elegans

Abstract

Gelsemium elegans is a traditional Chinese medicine that has been used to treat eczema, bruises, rheumatoid arthritis and skin ulcers for many years, and alkaloids are its major active and toxic constituents. This study aimed to comprehensively assess the quality of G. elegans samples including different plant parts and origins using ultra high-performance liquid chromatography coupled with photo-diode array and quadrupole time-of-flight mass spectrometry (UHPLC-PDA-QTOF/MS) and high-performance liquid chromatography coupled with UV detector (HPLC-UV). Firstly, the UHPLC-PDA-QTOF/MS approach was developed for the characterization of alkaloids in G. elegans and understanding the differences between multiple groups of samples. Based on the exact mass information, the fragmentation characteristics and the retention time of compounds, 38 alkaloids were identified or tentatively identified. 24 potential chemical markers for differentiating different plant parts of G. elegans were selected through PCA and OPLS/PLS-DA analysis. Secondly, a heatmap visualization was employed for clarifying the distribution of 24 selected alkaloids with high response in the UV. The roots, stems and leaves from Yunnan Province possess relatively consistent alkaloids composition, respectively. Most compounds in the root have a higher content than stems and leaves. Thirdly, a HPLC-UV approach was developed for quantitative analysis of three major alkaloids (gelsemine, koumine and gelsenicine) of G. elegans, and the results showed remarkable variation in the contents of these constituents. While, the contents of three alkaloids fluctuate relatively less in the stem. These results indicated that integrated chemical profiling and quantitative analysis of alkaloids in G. elegans from different plant parts and origins could be assessed by this method, which would establish the foundation for the application of G. elegans.