Identification of compounds in Lycii Cortex by UPLC-LTQ-Orbitrap-MS / 中国中药杂志

This experiment was performed to analyze and identify the chemical constituents of Lycii Cortex by UPLC-LTQ-OrbitrapMS. The analysis was performed on a Waters Xbridge Shield RP18( 4. 6 mm×250 mm,5 μm) column with the mobile phase of 0. 1%formic acid( A)-acetonitrile( B) under gradient conditions at a flow rate of 1. 0 m L·min-1 and the temperature maintained at 35 ℃ ．Electrospray ionization ion trap time-off light multistage mass spectrometry was applied for qualitative analysis under positive and negative ion modes. The results indicated that 55 compounds consisted of 39 phenolic amides,6 organic acids,3 cyclic peptides,2 coumarins and 5 others. In conclusion,an UPLC-LTQ-Orbitrap-MS method was established to qualitative analysis of Lycii Cortex in this study,and the fragmentation rules of phenolic amides were summarized,which provides a good foundation for further study of Lycii Cortex.

Analysis of aristolochic acids, aristololactams and their analogues using liquid chromatography tandem mass spectrometry / 中国天然药物

More than 80 aristolochic acids (AAs) and aristololactams (ALs) have been found in plants of the Aristolochiaceae family, but relatively few have been fully studied. The present study aimed at developing and validating a liquid chromatography tandem mass spectrometry (LC/MS(n)) for the analysis of these compounds. We characterized the fragmentation behaviors of 31 AAs, ALs, and their analogues via high performance liquid chromatography coupled with electrospray ionization mass spectrometry. We summarized their fragmentation rules and used these rules to identify the constituents contained in Aristolochia contorta, Ar. debilis, Ar. manshurensis, Ar. fangchi, Ar. cinnabarina, and Ar. mollissima. The AAs and ALs showed very different MS behaviors. In MS(1) of AAs, the characteristic pseudomolecular ions were [M + NH4](+), [M + H](+), and [M + H - H2O](+). However, only [M + H](+) was found in the MS(1) of ALs, which was simpler than that of AAs. Distinct MS(n)fragmentation patterns were found for AAs and ALs, showing the same skeleton among the different substituent groups. The distribution of the 31 constituents in the 6 species of Aristolochia genus was reported for the first time. 25 Analogues of AAs and ALs were detected in this genus. A hierarchical schemes and a calculating formula of the molecular formula of these nitrophenanthrene carboxylic acids and their lactams were proposed. In conclusion, this method could be applied to identification of similar unknown constituents in other plants.