A targeted strategy for analyzing untargeted mass spectral data to identify lanostane-type triterpene acids in Poria cocos by integrating a scientific information system and liquid chromatography-tandem mass spectrometry combined with ion mobility spectrometry

Rapid structural identification of natural compounds in the crude extract of traditional Chinese medicine by conventional liquid chromatography-mass spectrometry is complex and challenging. In particular, it is difficult to distinguish and identify structural isomers. In this work, we proposed a novel strategy that combines a typical ultrahigh-performance liquid chromatography-multidimensional mass spectrometry approach and the post-processing UNIFI scientific information system to rapidly identify lanostane analogs and isomers in Poria cocos. First, this strategy requires setting up a high-resolution key MS database and an in-house compound library. Then, ultrahigh-performance liquid chromatography coupled with high-resolution tandem data-independent mass spectrometry and ion mobility mass spectrometry was used to acquire untargeted multidimensional mass spectral data. Finally, a new and reliable multidimensional MS analytical workflow was developed to targeted filter the acquired data based on an in-house compound library via the UNIFI (TM) software. As result, a total of 121 lanostane-type triterpene acids were identified by high-resolution molecular mass, fragment ions, and collision cross-section values. Eight triterpene acids were unambiguously identified by comparing the retention time and MS/MS data with those of reference compounds. Three compounds were detected and reported for the first time based on their neutral losses, characteristic ions, and fragmentation pathways compared with those of known compounds. We anticipate that such an analytical approach can be extended to rapidly screen and characterize other herbal medicine compounds with multiple isomers. (C) 2018 Elsevier B.V. All rights reserved.