Rapid analysis on chemical constituents in roots of Rheum pumilum by UPLC coupled with hybrid quadrupole-orbit trap MS / 中草药

ABSTRACT

Objective: An ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbit trap mass spectrometry (UPLC-quadrupole-orbit trap MS) method was developed and used to rapidly recognize and identify the chemical constituents in the roots of Rheum pumilum. Methods: With 100% methanol as extract preparation for solution, the extract was separated on an ACQUITY UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 μm) and eluted with a gradient of methanol-water containing 0.1% formic acid. Mass spectrometry using positive and negative ion monitoring mode. The constituents in the roots of R. pumilum were rapidly recognized and identified by HRMS in the negative ion mode using both full scan and automatic triggering of the function of the two stage mass spectrometry scanning. Results: A total of 34 compounds, including 11 anthraquinones, 4 acyl indicans, 3 tannin precursor and tannins, 9 toluylenes, 2 flavonoids, 3 nai glycosides, and 2 benzyl butyl ketones were identified. Among them, 7 compounds were unambiguously identified by comparing with the reference standards and. 28 chemical compositions were reported for the first time in the roots of R. pumilum. Conclusion: The high resolution mass spectrometry database has been established by UPLC-quadrupole-orbit trap MS and the fragmentation pattern of reference substances is summarized. Many constituents from the roots of R. pumilum could be rapidly analyzed and identified. This study demonstrates that the UPLC-quadrupole-orbit trap MS is a powerful, rapid, and accurate tool in the structural identification of unknown constituents in Chinese herbal medicine with a good application prospects.