Identification and characterization of the chemical constituents in the roots of Ilex asprella by high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry

The roots of Ilex asprella (Rla) are a well-known traditional Chinese medicine for the treatment of viral and bacterial infectious diseases, such as influenza, tonsillitis, sphagitis, and trachitis. However, due to the complexity of the chemical constituents in Rla, few investigations have acquired a comprehensive understanding of material basis. High-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) was used for the identification of chemical constituents from the extract of Rla in negative ion mode. Their chemical structures were tentatively elucidated based on exact formulas, fragmentation patterns and literature data. A total of 32 compounds were discovered and tentatively characterised in Rla, including 4 phenolic glycosides and 28 triterpenoid glycosides. 10 compounds have not been previously reported in Rla and 8 of them have not been previously reported in the literature. The chemical composition of Rla was identified and summarised, providing a basis for further study on Rla.