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Quassinoids, the predominant constituents in the seeds of Brucea javanica (BJ), have gained an increasing interest over the past decades since the discovery of their extensive biological activities. In the present study, a method based on the segment and exposure strategy coupled with two mass spectrometer data acquisition techniques was firstly developed and validated for comprehensive profiling of quassinoids in the seeds of BJ via high-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS). The segment and exposure strategy could significantly improve the detection efficiency for trace quassinoids in the seeds of BJ. Furthermore, the five-point screening approach based on modified mass defect filter (MDF) and the visual isotopic ion technique could rapidly screen the precursor ions of interest. The fragmentation behavior of quassinoids was systematically investigated, and a total of 148 quassinoids including 86 potentially new ones were unambiguously or tentatively identified in the seeds of BJ. Collectively, our results demonstrate that the integrated strategy reported in this study has considerable potential for rapid screening of natural compounds especially for the trace ones in herbal medicines. [ABSTRACT FROM AUTHOR]

Absolute quantification of triacylglycerols (TAGs) in plant oils is a challenge for analysts, because most of the necessary chemical standards are unavailable. In this study, a new method for absolute quantification analysis of multi-components by use of a single marker (AQAMS), using two crucial technologies, evaluation of the collection recovery without chemical standards and enzymatic hydrolysis, was used for determining the absolute content of TAGs in brucea javanica oil (BJO), using glycerol as the marker. The TAGs in BJO were initially characterized using ultrafast liquid chromatography tandem atmospheric-pressure-chemical-ionization mass spectrometry. Then the TAGs in BJO were individually collected, by target-fraction collection via high-performance liquid chromatography coupled with an evaporative-light-scattering detector (HPLC-ELSD), and their recoveries were calculated by use of a novel non-standard evaluated recovery strategy (NSER). The results revealed that the collection procedure was feasible and reliable. Finally, modified commercial TAG assay kits using glycerol as the marker were used to determine the absolute abundance of individual TAGs in the plant oils. Comparing the result with that obtained by HPLC-ELSD analysis using triolein standard, the content of triolein determined by AQAMS was closely matched. The proposed strategy is a practical measure for solving the problem of the lack of chemical standards, and provides a new method for absolute quantification in natural products of multi-components with the same backbone. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]