Trace amounts of components in traditional Chinese medicine are considered pharmacological active substances used for treating many serious diseases. However, purifying all the trace substances and making clear their structures are not easy. In this context, high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry based molecular networking was applied to investigate the chemical constituents of the roots of Aconitum kusnezoffii Reichb., which led to the identification of 33 nodes in different groups (N1-N33). Based on the excremental fragmentation pathway of known diterpenoid alkaloids (1-9) and comparisons of characteristic ions and characteristic loss of analogs in literature, the structures of unknown ions were deduced. This work lays a foundation for the evaluation of the clinical basis and mechanism of traditional Chinese medicine from the aspects of chemistry. In this paper, the method speculation of unknown natural products by means of molecular network method is expected to be applied in the discovery and change law of relevant active components in clinical pharmacology and the change of complex systems caused by trace active compounds.

Developing methods for the systematic and rapid identification of the chemical compositions of fresh plant tissues has long attracted the attention of phytochemists and pharmacologists. In the present study, based on highly efficient sample pretreatment and high‐throughput analysis of high‐performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry data using molecular networks, a method was developed for systematically analyzing the chemical constituents of the fresh flowers of Robinia hispida L. and Robina pseudoacacia L., two congeneric ornamental species that lack prior consideration. A total of 44 glycosylated structures were characterized. And on the basis of establishing of the fragmentation pathways of 11 known flavonoid glycosides, together with the molecular networking analysis, 18 other ions of flavonoid glycosides in five classes were clustered. Moreover, 15 soyasaponins/triterpenoid glycosides were tentatively identified by comparison of their tandem mass spectrometry characteristic ions with those reported in the literature or the online Global Natural Product Social Molecular Networking database. The water extracts were separated by flash chromatography, which resulted in the discovery of one new compound, named rohispidascopolin, along with five known entities. The pharmacological targets were predicted by SwissTargetPrediction.

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