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.
ABSTRACT
A quantitative analytical method of ultra-high performance liquid chromatography (UPLC) was developed for simultaneously determining twelve components in Tibetan medicine Zuozhu Daxi. SIMPCA 12.0 software was used a principal component analysis PCA) and partial small squares analysis (PLSD-DA) on the twelve components in 10 batches from four pharmaceutical factories. Acquity UPLC BEH C15 column (2.1 mm x 100 mm, 1.7 µm) was adopted at the column temperature of 35 °C and eluted with acetonitrile (A) -0.05% phosphate acid solution (B) as the mobile phase with a flow rate of 0. 3 mL · min(-1). The injection volume was 1 µL. The detection wavelengths were set at 210 nm for alantolactone, isoalantolactone and oleanolic; 260 nm for trychnine and brucine; 288 nm for protopine; 306 nm for protopine, resveratrol and piperine; 370 nm for quercetin and isorhamnetin. The results showed a good separation among index components, with a good linearity relationship (R2 = 0.999 6) within the selected concentration range. The average sample recovery rates ranged between 99.44%-101.8%, with RSD between 0.37%-1.7%, indicating the method is rapid and accurate with a good repeatability and stability. The PCA and PLSD-DA analysis on the sample determination results revealed a great difference among samples from different pharmaceutical factories. The twelve components included in this study contributed significantly to the quantitative determination of intrinsic quality of Zuozhu Daxi. The UPLC established for to the quantitative determination of the twelve components can provide scientific basis for the comprehensive quality evaluation of Zuozhu Daxi.